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APPROPRIATE INDUSTRIAL TECHNOLOGY FOR PAPER PRODUCTS AND SMALL PULP MILLS UNITED NATIONS INDUSTRIAL DEVELOPMENT ORGANIZATION Vienna
Monographs on Appropriate Industrial Technology No. 3
APPROPRIATE INDUSTRIAL TECHNOLOGY FOR PAPER PRODUCTS AND SMALL PULP MILLS
*mr UNITED NATIONS New York, 1979 The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Mention of firm names and commercial products does not imply the endorsement of the United Nations Industrial Development Organization (UNIDO). Material in this publication may be freely quoted or reprinted, but acknowledgement is requested, together with a copy of the publication containing the quotation or reprint. All the material selected for the monographs has been revised by the secretariat of UNIDO to meet space and publication requirements. The views expressed are those of the authors named and do not necessarily reflect those of the secretariat of UNIDO. EXPLANATORY NOTES
A full stop (.) is used to indicate decima's. A comma (,) is used to distinguish thousands and millions. A slash (/) is used to indicate "per", for example t/a = tonnes per annum. A slash between dates (for example, 1979/80) indicates an academic, crop or fiscal year. A dash between dates (for example, 1970-1979) indicates the full period, including the beginning and end years. References to dollars ($) are to United States dollars. References to rupees (Rs) are to Indian rupees. In October 1978 the value of the rupee in relation to the dollar was $ 1 = Rs 7.90, The word billion means 1,000 million. The word lakh means 100,000. The following notes apply to tables: Three dots (...) indicate that data are not available or are not sepa- rately reported. A dash (-) indicates that the amount is nil or negligible. A blank indicates that the item is not applicable. Totals may not add precisely because of rounding. In addition to the common abbreviations, symbols and terms and those accepted by the International System of Units (SI), the following have been used:
Economic and commercial terms
c.i.f. cost, insurance and freight f.o.b. free on board GNP gross national product
Organizations
ATDA Appropriate Technology Development Association FAO Food and Agriculture Organization of the United Nations SFRI Swedish Forest Research Institute SIMO Société Industrielle du Moyen Orient Technical abbreviations and symbols (with approximate metric or other equivalents) acre 1 acre = 0.405 ha ft foot (1 ft = 30.5 cm) ft2 square foot (1 ft2 = 9.29 dm2) gal British Imperial gallon (1 gal (Imp) 4.546 litres) hp horsepower (1 hp = 746 W) in. inch (1 in. = 2.54 cm) rpm revolutions per minute
Technical terms
BOD biochemical oxygen demand CMP chemico-mechanical pulp COD chemical oxygen demand CTMP chemicothermomechanical pulp G.E. General Electric brightness meter reading GWP stone-ground wood MP mechanical pulp NSSC neutral sulphite semi-mechanical pulp RMP refiner mechanical pulp The concept of appropriate technology was viewed as being the technology mix contributing most to economic, social and environmental objectives, in relation to resource endowments and conditions of applica- tion in each country. Appropriate technology was stressed as being a dynamic and flexible concept, which must be responsive to varying conditions and changing situations in different countries. It was considered that, with widely divergent conditions m developing countries, no single pattern of technology or technologies could be con- sidered as being appropriate, and that a broad spectrum of technologies should be examined and applied. An important overall objective of appropriate technological choice would be the achievement of greater technological self-reliance and increased domestic technological capa- bility, together with fulfilment of other developmental goals. It was noted that, in most developing countries, a major development objective was to provide adequate empl/>yment opportunities and fulfilment of basic socio-economic needs of the poorer communities, mostly resident in rural areas. At the same time, some developing countries were faced with considerable shortage of manpower resources; in some other cases, greater emphasis was essential in areas of urban concentration. The appropriate pattern of technological choice and application would need to be determined in the context of socio-economic objectives and a given set of circumstances. The selection and application of appropriate techno- logy would, therefore, imply the use of both large-scale technologies and low-cost small-scale technologies dependent on objectives in a given set of circumstances. Report of the Ministerial-level Meeting. Interna- tional Forum on Appropriate Industrial Technology
VII
0°ilí°¡
CONTENTS
PiW
Foreword xi Preface
PART ONE Issues and considerations
Note by the secretariat of UNIDO 3 Report of the Working Group 12
PART TWO Selected background papers
THE PULP AND PAPER INDUSTRY IN BRA2TL 5. Klabin 23
EVOLUTION OF THE PULP AND PAPER INDUSTRY IN THE PHILIPPINES P. M. Picornell 26
APPROPRIATE INDUSTRIAL TECHNOLOGY: APPLICATION IN THE PULP AND PAPER INDUSTRY IN THE PHILIPPINES J. O. Escolano and F. N. Tamolang 30
THE PULP AND PAPER INDUSTRY IN EGYPT M. A. El Ebiary 36
^240 THE EXPERIENCE OF A DEVELOPING COUNTRY OF AFRICA V. L. Moorthy 43
STRATEGIES FOR DEVELOPING PULP AND PAPER INDUSTRIES IN DEVELOPING COUNTRIES A. D. Adhikari 53
FURTHER DEVELOPMENT OF MINI PAPER TECHNOLOGY IN INDIA M. K. Garg and M. M. Hoda 66
i.\ CONTENTS (continual)
THE SEARCH FOR AN APPROPRIATE TECHNOLOGY FOR THE PAPER AND BOARD INDUSTRY OF THE UNITED KINGDOM D. Attwood 7#
PULPING TECHNOLOGY AND REQUIREMENTS AND POTEN- TIALITIES OF DEVELOPING COUNTRIES G. Gavclin #1
APPROPRIATE TECHNOLOGY FOR A LOW-COST PAPER PRO- JECT TO STIMULATE THE RURAL ECONOMY /. Jeyasmgam 95
PROSPECTS FOR ESTABLISHING VIABLE SMALL-SCALE PULP AND PAPER INDUSTRIES IN DEVELOPING COUNTRIES Food and Agricultural Organization of the United Nations 98
PAPER, PAPER PRODUCTS AND PULP MILLS A. Western K)g nOnül SMALL PULP AND PAPER MILLS IN DEVELOPING COUNTRIES u **-T« AND THEIR RECOVERY SYSTEMS H. H. Hackland L. W. P. Ehling 123
UNIVERSAL PULPING E-S. Prior 133
(W\}Y) A PROSPECTIVE FIBROUS RESOURCE FOR PULP AND PAPER \S\K\4. IN INDONESIA - ALANG-ALANG (Imperata cilindrica) R. Joedodibroto 1^5
LIME BURNING AND ALKALINE PULPING J - Leffler 139
Annexes I. Selected documentation published or compiled by UNIDO relating to the subject 145
II. Working Group participants and observers 149 Foreword
As part of its effort to foster the rapid industrialization of developing countries, the United Nations Industrial Development Organization (UNIDO), since its inception in 1967, has been concerned with the general problem of developing and transferring industrial technology. The Second General Conference of UNIDO, held at Lima, Peru, in March 1975, gave UNIDO the specific mandate to deal in depth with the subject of appropriate industrial technology. Accordingly, UNIDO has initiated a concerted effort to develop a set of measures to promote the choice and application of appropriate technology in developing countries. Approp'riate industrial technology should not be isolated from the general development objective of rapid and broad-based industrial growth. It is necessary to focus attention on basic industrial development strategies and derive from them the appropriate technology path that has to be taken. The Lima target which, expressed in quantitative terms, is a 25 per cent share of world industrial production for the developing countries by the year 2000, has qualitative implications as well. These comprise three essential elements: fulfilling basic socio-economic needs, ensuring maximum development of human resources, and achieving greater social justice through more equitable income distribution. Rapid industrialization does not conflict with these aspirations; on the contrary, it is a prerequisite to realizing them. But, in questioning the basic aims of development, we riso question the basic structure of industrial growth and the technology patterns it implies. Furthermore, it is easy to see that the structure of industrial growth that should be envisaged and the corresponding structure of technology flows should be different from what they are today; a fresh approach is called for. This does not mean that the flow of technology to the modern sector and the application of advanced technologies are unnecessary. On the contrary, it is essential to upgrade the technology base in general, and it is obvious that to provide basic- goods and services, there are sectors of industry where advanced or improved technology is clearly necessary. It would be difficult to envisage a situation where the dynamic influence of modern technology is no longer available for industrial growth and development in general. However, an examination of the basic aims of industrial development leads to the conclusion that there must be greater decentralization of industry and reorientation of the design and structure of production. Such decentralized industry in the developing countries calls for technologies and policy measures that often have to be different from those designed for the production of items for a different environment, that of the developed countries. As a result, there is a two-fold, or dualistic, approach to
XI an industrial strategy. Morever, the two elements in sueh an industrial strategy need to be not only interrelated but also integrated. In approaching the question of appropriate industrial technology from an examination of basic development needs, a mechanism is necessary to link and integrate appropriate industrial technology to the overall development process. Through such a process the concept of appropriate industrial technology could be placed in the mainstream of the industrial development effort. It is hoped that these monographs will provide a basis for a better understanding of the concept and use of appropriate industrial technology and thereby contribute to increased co-operation between developing and developed countries and among the developing countries themselves. It is also hoped that the various programmes of action contained in the monographs will be considered not only by the forthcoming meetings of the United Nations Conference of Science and Technology for Development and UNIDO III but also by interested persons working at the interface over the coming years.
Abd-EI Rahman Khane Executive Director
XII Preface
To focus attention on issues involved in choosing and applying appropriate technology, UNIDO organized the International Forum on Appropriate Industrial Technology. The Forum was held in two parts': a technical/official-level meeting from 20 to 24 November 1978 at New Delhi and a ministerial-level meeting from 28 to 30 November 1978 at Anand, India. In response to a recommendation of the ministerial-level meeting, UNIDO, with the help of a generous contribution by the Swedish International Development Authority, is publishing this series of monographs based mainly on documents prepared for the technical/official-level meeting. There is a monograph for each of the thirteen Working Groups into which the meeting was divided: one on the conceptual arid policy framework for appropriate industrial technology and twelve on the following industrial sectors: Low-cost transport for rural areas Paper products and smi'll pulp mills Agricultural machinery and implements Energy for rural requirements Textiles Food storage and processing Sugar Oils and fats Drugs and pharmaceuticals Light industries and rural workshops Construction and building materials Basic industries The monograph on the conceptual and policy framework for appropriate industrial technology also includes the basic part of the report of the ministerial-level meeting and some papers which were prepared for the Second Consultative Group on Appropriate Industrial Technology, which met at Vienna, 26-29 June 1978.
XIII PART ONE
Issues and considerations
UNIDO
INTRODUCTION
Paper is considered a prerequisite of modern existence. Correlation has liv n?Th" en ,hC "-f• '" "*<*r of a country and its sia d "d , living The importance of the pulp and paper industry has long been recô.n zed many developing countries are desirous of establishing their own inaufnTto d eS C needS Many ,tem as telwell Tsas TOUTof pulp rfor conversion" ' into paper"' The ^ sunnlv «>" of¡-"Pom nan,, oT^S ;l tu r • ^howevcr^becomin8 ¡--AÍA
W Reduced availability and high cost of traditional raw materials rendermg the production of common varieties of paper una.trac te h retato! to investment, as well as ,o the profitability „f «ter grades of paper
(b) Decime m investment owing ,„ ,he increasing cost intensity of conventional paper-maktng, and low profit margins; * Disparity of consumption levels For developed countries, per capita consumption levels exceed 100 k»/a CreaSÌng arOUnd S Per Cem a ed levelskvehX of the d'^developtng 7 countries " range from 20 •kg/a*' "" The problem To achieve a minimum per capila consumption of 30 kg/a, the developing countries would need around 100 million t/a of additional production capacity. Assuming that the greatest use for such an increase would be for writing and printing paper grades and newsprint, approximately 30 million t/a of long-fibre pulp and 70 million t/a of short-fibre, hardwood or similar pulp would be necessary. The implications in terms of fibre requirements and investment needed are staggering. The raw materials required for such pulp would present no insuperable difficulties in availability but considerable problems in orderly exploitation. The capital intensity for the exploitation operations by modern standards would be prohibitive for most developing countries. The scale accepted as economic for production cannot be absorbed domestically, while export as finished materials can be ruled out as a practical alternative because of the intense competition from developed countries that are already producing for export. Even otherwise, the scale and sophistication of paper production have advanced to levels where conventional wood-pulp mills have become almost prohibitive in terms of capital investment. The standard size of new plants working on wood fibres, ranges from 500 tonnes per day (t/d) to 1,00/t/d and costs over $300,000 per unit of capacity, or $150 million to $300 million for a complete plant. The tendency in developed countries is to install increasingly larger pulp mills, mainly to reduce the operational costs per unit of production, which have increased steeply in conjunction with the sophistication and requirements necessitated to improve the product quality, chemical recovery and efficiency in pollution control in the pulp-production process. Developing countries having long-term plans to establish paper-production capacities are thus faced with problems originating, on the one hand, from the compelling need for development of domestic production capacity and, on the other, from the size, sophistication and cost of the conventional technology. The size and sophistication of conventional paper-making machines have grown in response to the pulp yield of the conventional modern pulp mills. The need for mass-scale production as a way of survival in the international paper trade has more or less compelled paper-production technology to increase the size and speed of paper machines. Over the past several decades, the paper machine has increased in width from 2 m to around 10 m and operating speeds have increased from about 100 m/min to 900 m/min. In terms of annual production capacity, the single machine has moved from approximately 500 t/a to upwards of 15,000 t/a. As a result, paper production based on conventional processes has become prohibitive for developing countries in terms of both the production volume in relation to domestic market and of cost. I. OBJECTIVES Because the difficulties of establishing paper production capacitit s based on modern conventional technology have proved so intractable, the idea has grown that another option, to build small, viable mills, should be possible. The need of developing countries to establish their own production capacities is so compelling, while the negative factors of establishing production capacities based on available modern technologies are so consequential, that the feasibility of establishing small, viable mills based on local available raw materials needs serious consideration. What may be more appropriate for most of the developing countries with low consumption bases and limited domestic markets, would probably be a process system designed around a small, simple, low-cost installation reasonably fast and flexible, to be operated with averse expertise and producing low pollution levels and being able to use all practical sources of non-wood fibrous material to produce paper. Paper and associated products must be cheap if they are to be available in sufficient quantities to the lowest-income population. The need for development of low-cost standard but versatile paper machines is extremely urgent. However, the established machinery manufacturers and leading consultants cannot be expected to develop the production of such equipment because the concept is contrary to their present production structure. It is therefore imperative that capacities to fabricate such machinery be developed, as far as possible, within the developing countries themselves. The wood-based fibre resources of developing countries are mainly tropical hardwoods, which are difficult to exploit and, from the pulping point of view less sat.sfactory than conifers. The exploitation of hardwood resources on the conventional scale requires a considerable infrastructure and is highly capital intensive. The use of corrosive chemicals and of high temperatures and pressures m many stages of the process also requires the installation of expensive and highly sophisticated equipment. The strategy for development of the paper industry in developing countries should therefore be based primarily on the utilization of alternative non-wood fibre resources on an appropriate scale. The objective of any strategy for development of paper production in the developing countries is, in the first place, to create domestic availability of the varieties of paper such as the writing and printing and newsprint grades and essential industrial grades of paper such as packing and wrapping paper and boards, within the following limits: (a) The capacity of plant and machinery should match the small and scattered nature of the domestic market, which is in turn difficult to integrate owing to internal transport bottlenecks; (b) The technology selected for the production of paper should be accessible in terms of the capital cost involved, cost of the resultant product, available material resources, skill and expertise, and domestic engineering capabilities; (c) The resultant products should be cheap, both absolutely and in relation to comparable products now imported. II. TECHNOLOGICAL OPTIONS Pulp-making processes and materials The sophistication of conventional paper technology has advanced to a level where it offers practically no immediate solutions to the specific problems and constraints of the developing countries. The conventional technology, which is based entirely on wood fibre and which produces highly bleached and sophisticated products, has no satisfactory answers for the technological needs of the use of non-wood fibres. However, the successful operation of small plants, some even of only 20 to 25 t/d capacities and using non-conventional fibres such as paddy straw, reeds and bagasse of the types found in Brazil, Egypt, India and elsewhere, may provide an option and may be seriously considered for widespread use in the developing countries. In general, it might be advisable for the developing countries to concentrate on alternative raw materials such as wastes from associated timber or agricultural industries and alternative fibre sources such as reeds, bamboo and straw. Pulp produced from these raw materials would, however, need to be blended with coniferous wood-pulp and other long-fibre pulp to improve their runability and to obtain the required strength properties while manufacturing lightweight printing and writing paper, kraft paper and the like. Secondary fibre can also be obtained from waste paper and used as part of the fibrous furnish for the production of all grades of paperboard such as cardboard and cartonboard and for the manufacture of substitute flutings and liners for case-making. Most developing countries are too deficient in coniferous tree species such as fir, hemlock, pine and spruce to produce the commercially developed long-fibre pulp. There are a few agricultural crops such as sun hemp, common hemp, sisal, abaca stems, banana stems and jute that could provide long-fibre pulp for developing countries. However, economic factors such as limited availability in terms of quantity, low yield of fibre per hectare and the high cost of preparing them, limit the use of these raw materials to only speciality grades of paper such as cigarette tissues and carbon paper at present. In recent years, work done on kenaf indicates the possibility of substituting this pulp in place of long-fibre crops and wood-pulp. However, further investigation of the suitability of this raw material would be required before it could be adopted on a commercial scale for the production of long-fibre pulp. Considering the present state of the development of alternative long-fibre pulp sources, it would be necessary for the developing countries to import long-fibre pulp to produce writing, printing and speciality grades of paper as well as certain industrial grades. A shift from wood to non-wood raw materials for the production of pulp is necessary not only for its own sake but also to provide an alternative to the conventional technology involving the installation of high-cost sophisticated plants for the production of wood-pulp. For achieving pulp brightness in small-scale operations, the bleaching sequence could be made simpler and avoid the use of the expensive chlorine- dioxide necessary to obtain high brightness. A simple system using hypochlorite in chest bleaching could, in many cases, produce pulp with sufficient brightness. 1* is possible to think of a viable pulp mill of 50 to 80 t/d capacity without the use of chlorine and caustic soda. The recovery of cooking used to produce wood-pulp involves highly capital-intensive processes and equipment. No answer has been found to this problem suitable for small-scale pulp plants and therefore, although it involves higher energy and chemical costs, some of the existing small-scale .SO to 100 t/d pulp mills still use the old-fashioned low heat-economy chemical recovery systems Processes using soda and batch digesters have been found to be particularly expedient for use in small-scale pulping plants based on non-wood fibre resources. The soda process may be particularly relevant to the needs of developing countries owing to its simplicity, low capital retirement and sulphur-free cooking. The use of batch digesters permits moie flexible operation, particularly where different types of raw materials are intended to be used. Soda and lime cooking is successfully practised in small-scale pulp production in Egypt, India and a few other developing countries, using straw, reeds, bagasse and other non-conventional fibre materials. There are, however, serious technical and economic limitations to the known processes for small-scale pulp-making, and these would need the specific attention of R and D in the future. There is no proven process for recovery of cooking chemicals used in small-scale pulp-making. This means that the black liquor containing as much as one half of the raw material feed and all of the cooking chemicals must be discarded. If chemical recovery were possible, dissolved organic material could be burnt and steam generated or recycled for cooking. Many developing countries have plans to develop sugar production based on cane. Small-scale paper mills based on surplus bagasse produced in cane crushing (about two thirds would be required by the sugar mills for their own use) can be established in conjunction with sugar mills. This will provide a commercial outlet for the surplus bagasse and also yield a low-cost source of raw material for paper mills. The fibrous constituent of bagasse is an excellent raw material for the production of pulp and paper; a number of paper mills based on it are in operation in Egypt, India and some Latin American countries. With the simple soda process, chemical recovery is practical at pulp production levels of 50 t/d and upwards, and paper production is viable at about the same level. Technologies have been developed and are available that use process systems designed around small, simple, low-cost installations capable of using all practical sources of fibrous materials to produce paper-making fibre. Machinery and equipment needed for such small-scale plants ranging from 15 to 100 t/d are fabricated in some of the developing countries and can, with advantage, be installed and operated in other developing eountries. The advantages of these processes, which are not available in large-scale modern pulp plants, are the following: (a) They are labour intensive; (h) They are simple in operation and maintenance; (c) They can be linked with other agricultural operations and industries; (à) They can be integrated with the existing levels of technological development; (e) They facilitate the profitable use of materials for which there is no other economic use. Furthermore, some of the raw materials available in developing countries, such as hemp, flax, cotton and jute, can be processed in small- cale plants for the production of special pulp grades that have great export potentialities. Papei-making machinery and processes Studies of the economics of operation of large-scale paper machines have revealed that mass production plants have no special commercial advantages over smaller plants. On the other hand, these studies reveal that paper machines of widths from 2.5 to 4 m, depending on the paper grades required and designed for speeds up to 300 m/min can be very economic as well as technically viable. Such machines, based on a few standard designs and rated to capacities of 25 to 100 t/d, can be produced in a number of developing countries and might, in general, be ideally suited to the needs of developing countries intending to produce paper mainly for import substitution. Such machines installed in the 1930s and even earlier are still in operation in a number of developing countries and have proved to be extremely versatile. The design and specifications have, however, in many cases, been adapted to suit local conditions and might, with further modification, be profitably adopted for local fabrication in other developing countries. It is also possible and would, indeed, be desirable to take advantage of genuine improvements achieved in paper technology in subsequent years, such as the combi-press pick-up, grooved or fabric presses, and substance and moisture control. The advantages of such small machines include: (a) Economy of capital cost; (b) Simplicity of operation; (c) High degree of labour intensity; (d) Adaptability to the substance range required; (e) Suitability in terms of decenualization and regional dispersal of the paper industry; (f) Ease of installation of additional paper machines sequentially, with cash-flow and operating cost benefits as well as in response to expansion of the demand for paper. HI. POLICY MEASURES of paper as ää;;• d * -"""•" 'ÄS' :; production based on non-wood fibre resoli• T., h- Í . P P Ipüüüipulp requirements, however, pla-^nToT^fi^ÄÄ^ "î enclaging resuLT P'dn,a"°nS gr"Wm* ,te sPeci« "-e yielded interSutXTro':^ conceF•dhewi' hSt ,5,0 yearS' R and D in the PaP" ¡"«-"'O- has been mainly concerned w,tht tlthe requtrements of the basic processes and innovations in lo machinery and equipment, particularly from batch to continuous operations, the introduction of computerized process control systems, the automation of various phases, recovery and recycling of chemicals used etc. The aims have been to improve product quality, eliminate losses, and increase production. Until recently, very little R and D was undertaken on alternative technologies, processes and raw materials to meet the specific needs of the developing countries. From what is known about the relative efficiencies of the small- and large-scale technologies, it is clear that innovations in the small-scale technology and processes should aim at improving the quality and strength of paper produced in the small-scale plants, and at facilitating the use of non-wood fibres and recovery of the chemicals used. This is an area where the working group could present a concrete plan of action to be taken up later by the developing countries and international organizations such as UNIDO as a part of their work programmes. The specific areas in which further R and D work is indicated include the development of a more versatile paper machine incorporating some of the genuine improvements noted earlier in the section Paper-making machinery and processes. To reduce the cost of such a plant, it could be designed for modular, pre-assembled construction to minimize site assembly requirements. The entire machine house and preparation plant could also be considered as a part of the standard design for modular construction. Also, further R and D work would be needed to solve the technological problems associated with the use of paddy and wheat straw to facilitate its wide-spread use in paddy and wheat-growing areas. IV. PROGRAMME OF ACTION In its national dimension, the programme of action might include the following: (a) Assessment of the long-term domestic requirements of paper on the basis of present consumption and growth trends, taking into account population increase, progress of education and overall development; (b) Identification of appropriate small-scale technologies based on non-wood fibres now in operation in some of the developing countries and assessment of their suitability to local conditions; (c) Establishment of domestic capabilities for the fabrication of plant, equipment and components based on existing small-scale technologies and processes; (d) Formulation and implementation of crash programmes for the development of plantations for the production of coniferous and other long-fibre species both as part of afforestation programmes and independently of them; (e) Encouragement, through a rational scheme of financial and technical assistance, of the establishment of small-scale paper mills as adjuncts to existing and future sugar and timber mills. Considerable technological expertise of a level of sophistication appropriate to the developing countries in general exist in a number of // developing countries, among them Brazil, Egypt and India. C o-operation and interaction among these and other developing countries can be greatly rewarding. Such co-operation can be fostered either on a b.lateral basis or through international agencies such as UNIDO. fariUt.Ate UNIDO FAO and other international organizations can greatly tacitate the establishment of paper industries in developing countries and may address themselves to the following programme of work: (a) Establishment of a comprehensive data bank on the snail-scale technologies developed and in operation in some of the developing countries, using non-conventional fibres, (b) Participate, both financially and technically, in national R and D projects in the field of small-scale pulp and paper technologies; (c) Assist in the establishment of regional research centres for R and D on specific alternative raw materials that are or may be available in these regions; id) Facilitate transfer and application of small-scale technologies from developing countries where such technologies are in operation to other developing countries by providing the requisite advisory services to them; it) Assist developing countries in formulating comprehensive production programmes that would include the establishment of production capacities for critical varieties of paper and paper products. Report of the Working Group DISCUSSION of »^Tvol^^•b,m Were disc^ed: fibre supplies scale -chine, utfetion a nXaTwTrUd'h"8' T"^ P~^ waste paper. of Wds,cs ¿"d by-products, and utilization of Fibre supplies hardwoods, bamboo, bagasse ,S u h wel|-es>ahlished sources as rCeds materials such as banana £,¿?a u/^'uT "l" ' ""«sdeve ^ The prospects for Inn» Rh showed promise. ' versati,ily„fb:mtao^J«- -ourees were less encouraging The no satisfactory process for „^',^f""f h»\"^ " be a goodUc. bu results as pulp but was more suiteble for n P, yet becn found- Hemp gave - forea concerted effort ¿Ä** «-Ä pressures of the harvesting mach „t wer" found '," ^'"P•"'- The ground been ach.eved in seasonally marshy •, r ,mP «* -se St: eStaWiSh ,0n8-fibre "**"««. «»•» as such or through appropriai ÄT^^""0"8 *" "*•»*. "-dwoods and, where ») Research into fas,.grüwing coniferous ^.^ (e) An interchange of development technology where advances have been achieved, as with work with grass species (alang-alang) in Indonesia, with reeds in Iraq and with the Manila-stripping process in the Philippines. Scale of operation It was agreed that, subject to product and substance range, integrated pulp and paper mills might be classified in terms of their capacities as follows: Small-scale, up to 30 t/d Medium-scale, between 30 and 100 t/d Large-scale, above 100 t/d With regard to viability of small-scale mills, it was agreed that they could be established and operated economically and were less harmful to the environment than larger ones. However, to ensure viability and adequate- product quality, it was considered more appropriate to establish non-integrated small-scale paper mills linked to parent pulp mills of adequate scales for the supply of quality pulp to those paper mills A 25-t/d bagasse-based paper mill producing wrapping paper ot the substance range from 60 to 120 g/m2 from a furnish composed of SO per cent bagasse, 10 per cent jute and 10 per cent waste writing paper was discussed. The overall bagasse consumption was 6:1 as pulp, and the bagasse was obtained by improving the thermal efficiency of the sugar mill. The paper mill was very profitable: two similar ones were under construction. Establishment ot such small-scale mills in conjunction with existing and future sugar mills was considered both desirable and appropriate in specific situations. One of the basic questions examined in that connection was whether it was the availability of raw materials or the availability of markets that should be the prime factor in any consideration of the establishment of a small-scale mill. It was generally agreed that availability of raw materials was in itself not a sufficient condition for the establishment of a paper mill. Nevertheless, since a market could be created, small paper mills should be set up wherever adequate quantities of raw materials were available, particularly in areas where there was sufficient local demand. A local mill had the advantage of lower transport costs. With regard to the product range for a viable small-scale plant, it was felt that packaging materials not requiring high technical qualities could be profitably manufactured. They included packing paper, corrugated paper, wrapping paper etc. Since gunny sacks were becoming scarce it was emphasized that paper must be progressively substituted for them. Demand for corrugated paper containers was also expected to increase rapidly. The advantages of solid board stiffened by lignin were emphasized. It was also asked whether ordinary grades of writing and printing paper could also be manufactured in small mills if standards such as brightness, tensile strength etc. of such paper could be relaxed. It was agreed that there was a market for handmade papers produced by small cottage-type undertakings, principally for prestige or for legal and archive papers. Efforts should be made to improve designs of machines used for such 14 small-scale hand production. It was mentioned that UNIDO could assist, on request, such efforts. Process constraints For unbleached products, appropriate technologies were available to contain pollution within limits. Bleached grades, however, presented greater problems. Recovery oí chemicals was a major constraint in the case of small-scale pulp mills. In this connection, the need for effective means oi desilication was emphasized. Progress had, however, been made by carboni/mg, and the mam problem now was not precipitation but separation. It was agreed that would be a fitting subject for sponsored research. The caustic soda process was recommended as less polluting, being free of sulphur and not requiring alloy steels. A new process which was still at the laboratory stage of development was described. The new process was based on the use of nitric acid, did not require pressure, was non-polluting, and was capable of circulating the black liquor to the paper-making process or of converting it to animal feed. Results of tests that had been undertaken were considered highly promising. A feasibility study for a 50-t/d plant using straw, was stated to have been commissioned. The process was considered appropriate from 10 t/d upwards. It was recommended that the carbonizing proccs be tried whereby the lignin could be separated at the liquid stage. Although tue lignin would still need evaporation or full drying, it would be of a higher concentration level and could result in a higher added value product such as carbon black. Since no satisfactory solution was readily available to the problem of full chemical recovery in small-scale plants, the low-pressure technoU ¿y prevalent in Sweden 25 years ago, with the improvements made on it in some of the developing countries, could be conveniently adopted. In that connection, development of satisfactory processes for desilication was considered as a priority area. It was pointed out that UNIDO could make use of assistance in testing from manufacturers of plant or pulp. An offer was made on behalf of a major mill in Egypt to undertake trials for desilication in close co-operation with UNIDO. The advantages of lagooning and natural evaporation were outlined by a participant with experience in the process. It was claimed that the process added considerably to the recovery and operational efficiency. Chemicals had been recovered after 10 years of lagooning, and the method was relatively inexpensive. The question of disposal of lime mud was raised; it was agreed that only 30 per cent of the lime mud, which could be reduced to 15 per cent in a bleached mill by using calcium hypochlorite and an additional slakei could be dumped when its silica content could be limited to 5 per cent. Generally, however, where silica content in the lime mud was a problem, lime was not recovered. It was dumped almost universally in India, for instance, with no apparent ill effects. There were a few isolated instances of its re-use as a fertilizer. Where soil conditions permitted, line mud was sometimes used as a fertilizer, but the sodium residues in the mud might adversely affect the soil and also crops In that connection, using a newly developed process ot lime mud with rice husks' to produce a new binding material was mentioned The possibilities ot fibre fractionation in conjunction with waste papei or bagasse pulps was discussed and were considered to have practical advantages together with a relatively low level ot investment The process had been successfully adopted tor waste paper Willingness to co-operate with IIN1DO in trial work on bamboo at a mill in Assam. India, was expressed ivlanpower training The importance of training tor local technical and managerial personnel was emphasized not only in view ot the ahsoluie need for development ot local expertise but also in view of the rising cost ot hiring expatriate technicians The cost for expatriate management had reached $10,000 per person per month. t was pointed out that, within the framework of its fellowship operations, UNI X) could organize individual training programmes at the request of Govi rnments. For instance, up to then, 300 fellowships had been awarded in the pulp :nd paper field. Training facilities existed in many countries, and some of them were described. Most of them accepted non-residents, at least to a limited degn e. A participant from India stated that 65 per cent of the technical personnel could be trained in the existing plants, and 25 per cent in the training institutions at relatively low cost. About 5 per cent might need other overseas training, but it should not exceed three months. The views of the meeting on training may be summarized as follows. (a) In-plant training is most satisfactory, but it should be undertaken effectively, with full facilities; (b) Overseas training is costly, disturbing to the trainees and not always satisfactory and should therefore be kept to a minimum; (c) UNIDO should prepare for general circulation a schedule of available training facilities; id) Because of the high costs of training. Governments should share at least 50 per cent of the cost; (e) Practical training, including maintenance training, is often difficult to impart. Consideration should be given to establishing demonstration units for this purpose, possibly ones producing speciality papers so as to recover some costs; if) A training scheme and a roster of instructors backed by a team of instructors should be taken up by UNIDO; ig) The language of the manuals and literature should be English, but expatriate instructors serving longer than one year should learn the local language; (h) The educational qualifications prescribed for trainees by some 1 "Cementitious binder from waste lime siudge and rice husk", Technical Note No. 75 (Roorkee, India, Central Building Research Institute, 1978). Ih institutions should be relaxed in vr».,,.,i . «.< I»«- sulfK-k-m turnes P "^ S",m' a"",tlia' *""** d<> '"» N-m^h'CJ^rX ht")''5' ,'hCi SWKl"Sh '"r"'ry """»<"> »> Vic, hal C U, ry Was ll b .raimngeostsCs WIK c iMimHkd stm^d at , 1$101Ï, million n and "V involved " "200 Su/pHkh ""' ~.~^ •"»i• and expatriate supervision lo, ,hc firs, yea, „I opcr.hon P ' ""' .Small-scale paper-making machine A participant outlined some work in prowess hv •• untivi, Cìovernmcnt aid on the •!,-««„ „i .. , , ,g y "lsh lons»r""ni. with meet optimun c Z ornic ZdlIZ I"'"-'•»1""* •*• ""at would development H ^' " '"'7^ "' Cany '" WÍ,h "* .hat would ne,,rp,,r,H ht t'w mac near'MP,rh"a,nS'rU,C'Cd P"PCT ^ demonstrated 1that for -n,,;!. , "^hme Mathematical analysis had pCr C 1 between Ï, „ 1 4 ,'''' ,",*m '°"" "'l""** - ""•• »P«in.u», width lav consumption ^JZl^t^l^T "" ""T• •• indicated. This mathematica „S , . P" minuk' (m/min» **• The machine ^^t^^Tl ? T•' Para"C' *""*" vaeuumless formers and he c-mJ, ,f , •"«""•¿"nier w„h optional g WÍdc ran e a rs hoard between T, o/m" and T 2 K" " " « '" P l* »»* .ha, economi s t t pe 1" tT*/ Pre"m|'nary C"S"ngS indic"'cd standardization could he acceniéd h„ ,L C C,aP"i'' "*' WOuld resu" if in .raining requirements AÏhï^ " ° consc«lue'"»1 ^»tages •he time feouled for^Tm ^ Ä io^T' ""'7/^ *"* «udi« were exited to be complete, ÇA nl 1,79 "'*" *"" *"***> Many established manufacturers did not favour the concent „f » countries. Some initial tsi^lgh, ^'n^sTT '" ^""T8 manufacturers in developing countries to estahlish 1 V •mu•& ">e of such machines. The estimafed potet a m" e (r 20 Z" ^""'T within the next two decades ' ' Such ""chines suggested .ha: ctrTI I 1P t;r,<:lmea i,' '"í •e "^"^ "" pressing ,„ eliminate the size pre» f<""n-jddlt've «««men. at the third Utilfcation of agricultural wasles and by-producis ju, I^'cS Z£^£Z%£Z<*« "»• *« --*• reeds, rubber p,an, residues and paírrHeaves " "' COCOnU* "*">• Success or encouraging results had been obtained with all of these in 17 relation lo various processes, including neutral sulphite semi-chemical (NSSC), cold soda and thermo-mechanical pulping (IMP), in addition to the more traditional processes. It was recommended that UNIDO be kept informed so that it could act as a central agency to provide information to others. In addition, the advantages of decentralization of the chipping operation in the production of pulp from bamboo at collection points in India were mentioned. The density of bamboo chips being higher than that of whole bamboo, the overall transportation cost decreased, while decentralization of the chipping operation helped in the dispersal of employment opportunities in the paper industry. Work in connection with pulping mixed hardwoods and blends of hardwood and bamboo and work in connection with the development of various tropical conifers were also described. The new harvesting methods for rice straw in Indonesia and the techniques and equipment developed for harvesting reeds in Iraq were described. It was agreed that work of that nature was of extreme value, and the co-ordination of such R and D was vital to avoid duplication of effort and to achieve accelerated progress. It was agreed that UNIDO should collect and disseminate relevant information in this regard through its Industrial and Technological Information Bank. Utilization of waste paper The availability of waste paper was considered as a function of annual paper consumption. For instance, in Malaysia, per capita paper consumption was 18.8 kg/a. However, in populated areas it reached 60 kg/a, whereas in rural areas it was as low as 2 kg/a. These figures indicated the potential for recycling where the population was dense. It was stated that the industry in Sri Lanka had benefited considerably by the collection and re-use of waste paper. The prime factor was to pay a good price. Paper makers in Sri Lanka paid up to 50 per cent of the price of equivalent pulp for mixed waste. A participant from India commented that the Government of India was encouraging recycling and waste utilization. However, it was stated that waste paper in Europe and North America was of a better quality, whereas in India, to the extent that it consisted of paper made with pulp made from bamboo, reeds, grasses etc., it could not be recycled. Newsprint waste was costly and was re-used many times, before it was available for collection. De-inking, although techni- cally feasible, was therefore difficult and not worth while in general. The policy adopted in Iraq was outlined. By Government decree, paper must not be dumped. Re-use had quadrupled since that measure was taken and was then 9,000 t/a and was expected to reach 27,000 t/a by 1981. Government policy possibly had the greatest influence in that success. A feasibility study was then in hand for the establishment of a collecting and sorting centre. Indonesia had a number of small mills entirely based on waste, producing mainly wrappings and chipboard. In consequence, the price per tonne of mixed waste had increased from 10 rupiah to 45 rupiah, but the mills were still IS , e ,he W I/d 4 1/d SCale WaS,e neWS rim WaS used and !;n!'!cost ,n!,100 rupiah , per '" tonne. ° ' ' '' "> «•PP¡"8 rearanSaÍd ^ Waf "PaPer col,ection and re-use in the Phillippines had ^Sr consumpt,on-statist,cs md,catmg thc ,m^ • It was agreed that the waste available from the United States of Ameriea was good, being practically virgin fibre. The majority of such waste arose near the eastern coast, where shipping was available, and it offered a good opportunity or low-cost long-fibre supplies. In the United States, it was stated that waste com rvg fh I doWn8raded the quality of the paper; in Europe, on the contrary, the emphasis was on upgrading. that OUt f 3 000 l of a er now bein mnnih" ^MT f T ^ ° ' P P S •P°rted per month 600 t of waste were recovered because, by contract, 20 per cent ot the paper supplied to packers must be returned. The system was working A recent UNIDO study revealed that Malaysia had 13 mills, all based on waste, but expatriate technicians were disappointed to find up to 30 per cent losses as fibre. There was a need for technical advice 1 noíftPafríÍCÍPfn!L8aVf nhe eXample °f a mil1 in EnSland that was Producing 1,000 t of waste-based fluting where the losses were less than 3 t and there was virtually no effluent. !raSfmerÌOn!dùhat SWeden WaS consider*ng legislation making it compulsorymm for households, offices and the like to collect and grade waste paper n e SP r t mlI, f de inked recentlyrecent!v beenbeë n commissioned. ° ?°° ^ '^ ^ "^ °" ^ock had The development of techniques for the utilization of wastes was emphasized. In the Federal Republic of Germany, 100 g/m* liner and flutmg were being produced from an all-waste furnish, and they performed satisfactorily representing 25 per cent of the market. In the United States, liner of less than 160 g/m2 was rare. Some participants suggested that further information be circulated on fillers and additives. Generally, the group recommended maximum use and upgrading of waste-paper resources. They asked whether UNIDO would sponsor an up-to-date paper on the subject. It was commented that such a paper had been prepared in 1971 and might be updated.2 Work now being undertaken in Europe in the dry treatment, cleaning and deftbenng of waste paper was described. The process offered the advantages of reduced waste and steam consumption, low energy input and reduced pollution. II. POLICY Government policies Participants from India and Kenya described the policies of their respective Governments with regard to the paper industry. In India, mills above a specified 2 "Collection and utilization of waste paper in Ceylon" (ID/WG.Ï02/9). he S d fi "nd mus, pay an ¿^^jh^TI Ï7"? '" °' "* " *«< "*« USC ra mal s »•her than bamboo, acc, dL ,, ,hc s ' 1X1hc•*"% Î!" "' " •" exempt from ,h, <)b|j • ¿.'" "^ °' ""»• Waller mills were als,, PCr C production »f »rdinary^riúU a d Pr nl¡n"fn T' '" '*"" "P*¡'¡<* »» eeni refund of ,he excise 2t Z g P PCr a"d C"uld "blain UP "> " Per -¡"s were granted c^Ä^S,'" ^ ,'" K"^- " "« »tated 1 malC ls C U d wt competing imports a„d ob, 7^ rn ', nT" """ • ' ° ' " retirements sueh as housing ^^^^^ **»°">• *» mfrastruetura, y a h Ugh ^vU^fX ,r^4 '^ ;; -T-1 '«"" P— as 'he objective of cheap paper s iL '" ,t. 'f"""" ^ '"efficiency and defeated during the early years «ff de e „ten f,h"" ^ "'","dcrcd csscnlial :" '«*> f»r government protect ""H«m £ Zuïd'tT A ?"*"* ^ assistance with infrastruclural costs dmv^v formulated, such as m s mills, relaxation of poUutior^¿^^ """" - <« "-'lief and. for sma,l Banking policies n for more faraurabie deb, ^tri'^uti::' ä :h r «"%-«- paper projects and the need „ dlvelolen ' 7 "*" '" the CapiU" inlCTsi» <"< P per nduS,ry in countries, institutional credi, „ould be ? M" " ' ""eloping 0 Ìhera lmns A range varying from -NÍD £.T " ' ' - recommended that for deve 1^ S'a,ed '" bc Wimble. I, was with fav„urab,e longtrnToanTrtn^•5' "" bankS Sh»"ld «"»« «=* ,KUllKS »«nnr;„^\Xt^ll^ f' <*<**"<«« i" some second-hand machinery. There was a nee^f Pr<>JCC'S inTOlïing imp,m of assess and certify the eredi, worthiness o,,H C°mPe,ent 'echnical »**** ,o hmaf and certify on the conditio I )e eeÒnd uLTT'nd """ ' '" '" •<•< «rder ,„ ahlain finance fmm^•^' •*•»»«gh« to be imported in preconditions in many of the devel.m „ ü'ff,cu" '" fulfil those financial institutions "we egenerav^TT "• a'S° P°in,ed "»' '"* use of second-hand plants. The as is,a„ce of i'l^nn'"8 Pr°JeCIS inVolvin8 Ihe reputable independen, agencies tovanW J, ? u•5 reques,ed ,0 idenlify ffered such se while national Government ml, .K'" """ ° •es financial institutions to enaWe ?^ÌL"Tj ^Z "" 'endin* ^¡cies of '"voting the use of seo.n^^t,^^ «* -eds o, projects HI. PROGRAMME OF ACTION nation SKaSr a Pr08ramme °f aCti0"t0 * follo-d o- -he 20 National level (a) The long-term domestic requirements should be assessed, extrapolating factors such as population growth trends, increases in living standards and consumption, and progress in education; (b) Small-scale pulping and paper-making technologies now in operation in some developing countries should be identified and assessed as regards their suitability to various local situations; (c) The establishment of local (national or regional) capabilities for fabricating the plant, equipment and components to support small-scale technologies; (d) The formulation and implementation of crash programmes to develop plantations of coniferous and other long-fibre species for the production of wood-pulp. These programmes could be part of larger programmes for afforestation or separate from them; (e) The establishment of small-scale paper mills associated with sugar and timber mills should be encouraged through a rational scheme of financial and technical assistance. International level Considerable technological expertise appropriate to developing countries already exists in some of them, among them Brazil, Egypt and India. Co-operation among such countries and between them and the less developed countries should be encouraged. Such efforts could be fostered bilaterally, through international organizations such as UNIDO, or in both ways. UNIDO, FAO and other members of the United Nations system could approach these problems in the following ways: (a) The establishment of a comprehensive data bank on appropriate pulp and paper operations that use non-conventional fibres existing in some developing countries; (b) Participating, financially and technically, in national R and D efforts in small-scale pulp and paper technologies; (c) Assisting in the establishment of regional R and D centres on specific alternative fibrous raw materials that are already available or that could become so; (d) Facilitation of the transfer and application of small-scale technologies from countries where they exist to others by providing the needed advisory services; (e) Assistance to developing countries in the formulation of comprehensive production programmes that would include the establishment of production capacities for paper and paper products for which there is special need. PART TWO Selected background papers I The pulp and paper industry in Brazil S. Klabin* It should be understood that the history of the development of pulp and nacer manufacture in advanced industrialized countries cannot be repeated today The primitive labour conditions, the lack of pollutton control and « economics oi production prevalent in the early days of the tndustnal revoluta phases of developmenf and problems experienced by already "riutrufeed coumries h must face other complex challenges. Techmcal developments >n ndtlhzed countries tend to involve methods that are more and more caMd inttn ve and less and less labour absorbent. The economtc s.ze of product on unitsTalso continuously increasing. Such a picture scarcely describe he ^litonsof a country or region without an industrial infrastructure. Unless drâs, c^hn canZvations ta\e place, which are unlikely, there is no way « a« fsÏÏl pulp müVcan compete on the world market. However, there Is room for sminale mills designed for domestic or regional markets protected aga ns, om£ton from abroad. Larger and more complex umts, compe«.« m he woZ market, may then follow the later development of .ndus.nal and personnel infrastructure. Technical options Softwood is conventionally used for wood-containmg pr.ntmg papers^ HoweTer Brazilian experience shows that fast-growing hardwoods can be used " welf wi h onsiderable savings in energy. Shortages of softwood or mechanical pulp have induced some producers to adopt ehem.-mechamcal nuToing of hardwood. Such chemi-mechanieal pulping wtdely d.scussed ahe ?97 European Committee for Cellulose and Paper Sympostum ,n Madnd nvo ves modest investment in comparison with chenucal pulpmg, creates only a Zderate pollution load, is adequate for hardwood and produces a pulp su.tab.e for nrintine and writing papers, including newsprint. taXng papers, the kraft process is the most suitable for a number o raw materials Thfs process requires quite heavy investment but, tn mos, cases, tt »Director, Cia. Fabricadora de Papel, Sào Paulo, Brazil. 2.? 24 is the only way to enter the packaging-paper field. The investment level can be reduced by compromising in heat recovery by using smelters instead of conventional recovery boilers. Additional direct-contact evaporators can be considered. Such an arrangement allows for smaller-scale 50 to 100 t/d units. There are several such smelters in operation in Brazil. Some of them obtain marginal capacity increases with positive results. For paper making, multi-grade machines are often the best technical option. Their efficiency may initially present problems, but later, when markets expand, such multi-grade machines can still be profitably utilized for a single grade without further investment. For example, there are integrated mills producing bleached and unbleached grades in a single machine without any noticeable loss of efficiency. As a general rule, in choosing technical options for new industries, it is advisable to stay with already well-proven processes and equipment and to adapt them to the local conditions. Human resources For a newly established industry, it is vital to get not only appropriate equipment but also appropriate personnel. After the Second World War, it was easy to find immigrants in Brazil who had backgrounds in the pulp and paper industry. Since then, however, education of personnel has become more and more important. Consequently, the pulp and paper industry has set up technical schools in co-operation with Government agencies. A research and development centre is also advisable for each mill or group of mills, depending on size. Experience shows that the success of an industry depends very much on its ability to adapt to local conditions and solve its problems from within. Industrial infrastructure In many cases, industrial infrastructure may cost more than the plant itself and, if the industry must build the infrastructure, the overall investment may invalidate the project. Therefore, industrial locations must be selected carefully and, in some cases, a pool of industries must share development costs. In Brazil, several industrial concentrations in new and remote areas have been developed. The results are still to be assessed. Industrialization policies International competition in the pulp and paper market has in many cases created quality criteria that do not serve the best interests of either the producer or the consumer. Brazil, facing a competitive domestic and international market, is no exception. It is felt that such a burden to production and investment should be avoided, particularly in developing countries that protect their industries against imports. Common sense should establish quality specifieations according to the end use of the products and not the quality standards required to compete in world markets. It is also imperative that a clear policy be adopted to provide even small units with adequate environmental control equipment, as later improvements will be costly and painful, leading often to early obsolescence. This additional capital cost for pollution control is partly compensated by the benefits of avoiding wastage of valuable raw materials. Finally, experience shows that strong government support is needed for developing country pulp and paper industries, particularly in sharing the cost of infrastructure and afforestation and setting, at least temporarily, a policy of import restrictions. Evolution of the pulp and paper industry in the Philippines P. M. Picornell* The establishment of a modern pulp and paper industry in a developing country such as the Philippines depends on: Availability of a market Availability of raw materials Adequate financing Realistic feasibility studies Proper design, construction and start-up Attitude of the Government These points are not listed in the order of importance. They are equally important, and a defic.ency in any one of them can have serious consequences The story of the development of the pulp and paper industry in the Philippines is typ.cal of what may be experienced in other developing countries It has examples of the effects of all the factors given above. It is a story of successes and failures, of projects gone sour and dreams come true. Onlv the h.ghhghtscan be ment.oned here, but it is hoped that these will enable the cader to get a clear picture. conskL0ffA,ogUStn1978; the PU1P and Paper industry in the Philippines consisted of 19 mills, only 5 of which were fully integrated pulp and paper mills. Their capacities and products are shown in the accompanying table HOW THE LOCAL PULP AND PAPER INDUSTRY DEVELOPED Before the 1 "30s the Philippines imported paper, either from China or the nmnZl iT*"' T^' Spai" (,565~1898) and «he united States 1Z >' C,°Untry d,d n0t haVe the market to >müfy mass Production of paper, and its vast forest resources were not believed suitable for this purpose However, the rapid development of the sugar industry and the development of iTfoeTwOs" maSS"Pr0dUCing Paper from straw and bamboo changed the picture In 1939, the Compañía General de Tabacos de Filipinas organized the Compañía de Celulosa de Filipinas which built the country's first pulp and paper mill, a 10 t/d bleached paper mill at Bais, Negros Oriental, based on bagasse from a sugar mill they controlled in this area (Central Azucarera Philipp^"" VÌCe PreSÌdent' PaPer IndUS,rÌeS COrp0ratÌOn °f the PhÌ"PPin-- Makati, Rizal. 26 PlJl P ANI) PAPI R Mil I S IN IUI PUH iPPINr S (1478) ( (i/HH m Name I'rodtuls (1 (MHIt ul Hrnuirk\ Aclem Paper Mills Printing writing, wrapping 6 600 B Arco Pulp anil Papei Co. Sanitary, wrapping. corrugating medium 4 440 B Balaan Pulp and Paper Mills, ne- Punting/writing 2S 200 A Central A/ucarera de Bais Printing writing, chipboard n 17 s A Container Corp. ol the Philipp mes Boxboard. chipboard IK (KM) B Hastern Paper Mills, Ine Corrugating medium, sack kratt 17 460 B Globe Paper Mills. Inc. Printing/writing, wrapping 8 4KO B Kimberly (lark (Philippines) 1 íe Sanitary 8027 B Manila Paper Mills. Ine Printing writing, sanitary, linei hoard, corrugating medium wrapping. sack krail. boxboard SO 240 B Men/i Development Corp. Printing writing 4 620 A Paper Industries Corp. of the Newsprint, liner board corrugating Philippines Bislig Mill medium 136 Mo A Paper Industries Corp. of the Philippines Iligan Mill Liner board, abaca pulp 30 (MM) A Philippine Paper Mills, ln< Boxboard. chipboard II 470 B Premier Paper Corp. Printing writing 2 200 B Scott Paper (Philippines) Printing writing, sanitary Ifi 500 B United Pulp and Paper Co.. Sack kraft 30 000 A Worldwide Paper Mills, Ine Others 8 US0 B Canlubang Sugar Estate, Inc. Abaca pulp C Isarog Pulp and Paper Co. Abaca pulp C aA = pulp and paper. B = p< iper only, ( pulp only de Bais). This mili used the Pomilio process, consisting of a mild caustic cook, chlorination with gaseous chlorine, followed by a conventional bleaching system. It now has a capacity of 45 t/d of bleached writing paper. In 1950, the Government-owned National Development Corporation brought in a 20 t/d paper machine to produce cement bags from imported pulp. This machine was later transferred to the APO Cement Corporation for the same purpose and operated intermittently for a few years but was finally shut down. In 1948, the San Miguel Corporation started up the first paper corrugator in the country, using imported container board. The popularity of this packaging product increased swiftly and created a growing demand for container board. Because of a deteriorating balance of payments position, the Government was forced to institute import controls in the late 1940s, and these continued through the 1950s. Such controls encouraged the establishment of a number of small paper mills operating on imported pulp or waste paper. The first of these was the Philippine Paper Mills, Inc., which started up in 1951 to produce chipboard from waste paper. Most of these mills have been successful, having been given a head start during a time when pulp and waste paper were readily available in world markets. Although they are all relatively small, it is doubtful that such mills could be built and operated profitably at present, when the supply of market pulp is tightening up. Since those days the Government of the Philippines has established a policy that no new mill that is not integrated with a 2 S pulp mill will be allowed unless it can get a long-term agreement with a domestic- pulp producer for its supply of raw materials. In I960, a group of local businessmen organized the Bataan Pulp and Paper Mills, Inc. to build a pulp and paper mill based on bamboo. This mill, with a capacity of 75 t/d of bleached writing paper, started up in 1962 but ran into serious problems with the supply of raw materials. The availability of bamboo turned out to be limited, and the mill had to compete for it with other users of this very versatile material. After a number of years of difficulties, this mill was successfully converted to use hardwood sawmill waste and is operating profitably at capacity today. During these years the need to establish a paper mill to produce cheap but high-demand papers such as newsprint and container board was evident, but two problems had to be solved in order to do so. Newsprint and container board are low-cost products, and a large market has to be available to justify a mill of the size to take advantage of the economies of scale necessary to produce them cheaply. The only raw material available in the Philippines in sufficient quantities to feed such a mill was wood. However, most of the woods available are hardwoods, which are short-fibred, and up to the late 1950s they were nt.t believed to be suitable for the manufacture of newsprint or container board. There are limited amounts of pine, a long-fibred species, available in the highlands of northern Luzon, but detailed surveys indicated that they could not be extracted in sufficient quantities or at a low enough cost for the economic manufacture of such low-priced products. In other words, to be able to produce newsprint and container board, both a market and a technology to process local raw materials were needed. However, the demand for these products was growing steadily, and the availability of a market sufficient to justify a mill that would give the desired economies of scale was but a matter of time. The use of domestic raw materials for this purpose was seen as the main problem. In 1950, Bislig Bay Lumber Company, Inc., began to operate a timber concession on the eastern coast of the island of Mindanao, which was to form the raw materials base for a large-scale pulp and paper mill. Bislig's leadership was confident that technology could be developed to use the short-fibred Philippine mahogany in the manufacture of paper and was particularly interested in producing kraft container board for use in the corrugated carton plant of San Miguel Brewery, Inc. A research programme was started on the use of Philippine woods for this purpose, and in 1953 Bisling Industries was organized to implement this project. Bislig Industries, Inc. is now the Paper Industries Corporation of the Philippines. In addition, the International Paper Company, the largest paper company in the world, joined this project, and by the late 1950s, after exhaustive tests which included full-scale mill tests carried out in International's mills in the United States of America, it was concluded that, with improved technology, both newsprint and container board could be made out of Philippine hardwoods' It took another ten years until the market grew to a point that would justify an economically sized mill and to iron out technical, legal, and financial details. Construction started in 1969 and the mill, with an initial capacity of 71,400 t/a of newsprint and 63,600 t/a of kraft container board came on stream in 1972. Start-up was not easy, as problems that were not evident in laboratory and pilot-plant work eame up in full-scale commercial operations, but they were solved one by one. Technology was perfected in actual operations, and capacity was expanded twice without major additions of machinery and equipment. By the end of 1978, the mill had a capacity of 100,800 t/a of newsprint and 73,000 t/a of kraft container board. This mill has proved beyond doubt that good-quality newsprint and kraft container board can be made out of tropical hardwoods, thus adding them to the list of raw materials for the paper industry throughout the world. In the late 1960s there was renewed interest in paper made from abaca (Manila hemp), because prices for high-grade papers increased, and this material became available as rope manufacturers, who previously took up most of the supply, turned to synthetic fibres. Therefore, Rustan Pulp and Paper Mills, Inc., built an abaca pulp mill at its plant at Iligan. Menzi Development Corporation built a pulp and paper mill at Talakag, also on the northern coast of Mindanao, and two abaca pulp mill', Canlubang Sugar Estate and Isarog Pulp and Paper Company, were built in southern Luzon. All of these mills are small (under 20 t/d) and manufacture a highly specialized product. In 1973, United Pulp and Paper Company built an integrated pulp and paper mill in Bulacan (Luzon) to produce 30,930 t/a of sack kraft for cement bags. This mill uses bagasse pulp manufactured in its own pulp mills and imports long-fibre pulp. In 1978, Cellophil Corporation broke ground for a 200-t/d pulp mill in the province of Abra (northern Luzon) to produce long-fibre pulp from the pine stands on the highlands in that region. This mill will start up in 1979 and is expected to supply a part of the long-fibre requirements of the country. The pulp and paper industry of the Philippines has been badly hit by the present recession. Developed countries have repeatedly dumped paper into the country at incredibly low prices, and have severely upset local markets. Nervertheless, the pulp and paper industry of the Philippines is starting to recover from the worst crisis of its short existence. A number of new mills are on the drawing board, although only that of Cellophil Resources Corporation is under construction. High costs and relatively low prices will continue to retard new construction for some time to come. However, it can be expected that the pulp and paper industry of the Philippines will survive the current crisis and emerge in a more efficient and stronger financial condition. Steps are being taken to increase the reserve of raw materials through an extensive reafforestation programme, and the country is expected to become a significant factor in the pulp and paper industry in Asia. Appropriate industrial technology: application in the pulp and paper industry in the Philippines J. O. Escolano* and F. N. Tamolang** INTRODUCTION Most developing countries lack the softwoods traditionally used to manufacture pulp and paper. They must therefore use other resources available to them to meet their raw material requirements for the production of different grades of paper, and there are specific instances where appropriate industrial technology will apply. For the purpose of this paper, the specific applications of appropriate industrial technology may be classified into two categories: (a) Small pulp mills using high-quality materials for speciality grade paper; and (b) Large-scale integrated pulp and paper mills using non-traditional raw materials. Although conventional pulp and paper mills require high investment costs, small pulp mills are economically feasible if the end-product commands a high market price as is the case with abaca pulp and the speciality papers made from it. Although the prevailing cost of abaca pulp is about four or five times that of coniferous wood pulp, there is increasing demand for it in world markets. The second category involves the application of alternative technology in the utilization of the available local materials. The utilization of mixed hardwoods presents complicated problems owing to the heterogeneity of species and properties, but it is imperative that developing countries adopt and develop new technologies suitable for the raw materials available to them. STATUS OF THE PHILIPPINE PULP AND PAPER INDUSTRY Philippine pulp production rose some 300 per cent to over 100,000 tonnes per annum (t/a) during 1971-1975. Paper and paperboard production climbed »Science" Research Assistant Chief, Forest Products Research and Industries Development Commission, College, Laguna 3720, Philippines. "Commissioner, National Science Development Board, Bicudan Mundingluba, Metro Manila, Philippines. 30 nearly 60 per cent to over 220,000 t/a during the same period. As a result, imports of paper and paperboard decreased over 70 per cent to some 40,000 t/a by 1975. This increase in pulp and paper production and the reduction oí imports was due to the operation of two integrated pulp and paper mills, both based on the utilization of mixed tropical hardwoods. At present, the Philippine pulp and paper industry consists of 22 firms; 6 integrated pulp and paper mills, 3 pulp mills, and 13 paper mills. Of the 6 integrated mills, 3 utilize mixed tropical hardwoods in their operation. These 3 mills alone account for 83 per cent of total pulp capacities and 46 per cent for paper and paperboard, which shows the important role which tropical hardwoods play in the Philippine pulp industry. Other raw materials used by the industry include abaca and sugar-cane bagasse. Additional fibrous material requirements of the paper mills are met by imported pulp (18 per cent) and secondary fibres (41 per cent). Research and technology transfer The Forest Products Research and Industries Development Commission (FORPRIDECOM) has been engaged in pulp and paper research for more than twenty years, and is the only such R and D institute in the Philippines. As an agency of the Government of the Philippines, FORPRIDECOM is willing to co-operate with both national and international organizations in the further development of appropriate industrial technology. The investigations have identified abaca and mixed hardwoods as the potential domestic materials for the production of various types of paper products, using differing pulping processes. Abaca Abaca is a perennial plant belonging to the banana family. About 90 per cent of the world's production is grown in the Philippines. Before the widespread utilization of abaca for pulp and paper, the bulk of production was utilized by the cordage industry. Recent trends, however, have led to increasing use of abaca for the production of a variety of high-grade speciality papers. Its desirable characteristics include high holocellulose and pentosan contents, and low lignin, ash, silica, alcohol-benzene extractives, and hot-water extractives. Furthermore, abaca has extremely long fibres (over 3.5 mm), and a thin cell-wall in relation to fibre diameter. Mixed hardwoods FORPRIDECOM has long conducted studies on the pulping and paper- making qualities of Philippine hardwoods. They demonstrate the suitability of mixed hardwoods for the manufacture of newsprint and other types of paper. Industrial application of appropriate technology Abaca pulping In the Philippines, there are at present four abaca pulp mills and one integrated pulp an paper mill. The total production of these mills 32 is some 18,000 t/a. All four are small mills with capacities of 1,000 to 6,000 t/a. There are three technical options that can be used: the alkaline-sulfite, soda, and kraft processes. Although the overall pulp strength properties obtained are almost the same for all three processes, the alkaline-sulphite process is preferred, owing to its higher yield. Most mills therefore produce alkaline-sulphite pulps. However, there are also certain instances where the end-user of the pulp specifies that either the kraft or soda process be used, and such small mills can easily shift from one pulping operation to another. The bulk of the abaca pulp produced is exported to the Federal Republic of Germany, Japan and the United Kingdom. The limiting factor on further increased usage is its prohibitive cost. If the price could be reduced, a tremendous expansion in the utilization of abaca for different grades of paper could be expected. Present prices vary in the range of $1,400 to $l,600/t. A small percentage of this abaca pulp is also used locally as part of the furnish for the manufacture of cigarette and other speciality papers. Utilization of mixed tropical hardwoods As mentioned earlier, tropical hardwoods contribute significantly to the Philippine pulp and paper industries-83 per cent of the total pulp capacities and 46 per cent for paper and paperboard. The largest mill in the country is an integrated wood-processing complex that includes veneer and plywood, sawmill and lumber processing, and wood-seasoning plants. It has a very selective pulping system wherein only logs with specific gravity of 0.55 or lower are accepted for pulping. These logs are then sorted out into light-coloured and dark-coloured woods. The light-coloured logs are used for the production of refiner-ground pulp, whereas dark-coloured woods are sent to the kraft pulp mill. The main products of this integrated mill are newsprint and kraft liner board. Other grades of paper are also manufactured, depending on the demand. The kraft line produces an easy bleach cook for the bleached pulp used in newsprint manufacture and a hard cook for the kraft liner board. The liner board is made from a blend of the hard-cook kraft pulp and a small percentage of imported kraft pulp. The imported kraft pulp is necessary to improve the tear resistance of the liner board. The newsprint mill can be considered unique in that it is the only such mill in the world that uses 100 per cent hardwoods, i. e. 30 to 40 per cent bleached kraft pulp and 60 to 70 per cent refiner groundwood (bleached with peroxide). The two other integrated mills do not have forest concessions of their own. Their raw material needs are supplied through purchased logs and wood-processing wastes. In spite of the heterogeneity of the species used, Philippine pulp and paper mills have overcome the attendant difficulties through the application of appropriate technology and the availability of highly qualified and well-trained technical personnel. Impact on regional development With the establishment of these mills, especially the mixed hardwood mills, new communities, together with attendant services and infrastructure have been established in areas that used to be wilderness. In the case of the abaca industry, a new outlet has been developed for the cordage industry, and for the handicraft or cottage industry. The export of abaca pulp has earned more foreign exchange and also resulted in the reduction of imports of flax pulp for cigarette paper manufacture. The existing production of newsprint is now sufficient to meet the local requirements, and it is planned to increase present capacity to meet additional projected demand. Furthermore, the operation of the mixed hardwood mills has encouraged planting of fast-growing trees for pulpwood. Recent trends in research and development Potentials of coconut trunk A massive replanting programme of coconut farms is scheduled to begin in 1980 to replace older low-yielding coconut trees. Under this programme, some 6 m3 of coconut trunks will be cut annually over 40 years. In anticipation of the forthcoming availability of a sizeable volume of potential raw materials, FORPRIDECOM has initiated studies on the utilization of coconut trunk. These indicate it could be a potential source of raw material for the pulp and paper industry. A new process and machine for fibre extraction A new and efficient process and machine for extracting and processing fibres from fibrous materials of agricultural and minor forest-products origin has been invented by the authors. The machine and process continuously extract abaca fibres with a fibre yield higher by 50 to 60 per cent than those of the other processes. Normally, these stripping wastes have practically no value and are left in the field to rot. It was found that good-quality fibres can be recovered when processed by the FORPRIDECOM machine and process. Construction of a commercial prototype is now in progress. In 1978, this invention won the Presidential Award because of its importance to rural development. A non-polluting pulping process Another FORPRIDECOM invention is a new process for producing high-grade chemical pulp. It utilizes the properties of potash liquor to dissolve the lignin and hemicellulosic components of fibrous materials while preserving the cellulose so that it can be recovered as a high-quality paper-making pulp. The spent liquor recovered directly from the digester has potential as a liquid fertilizer. At present, there are small pulp mills in the Philippines, where chemical recovery is not economic. This condition may be remedied by the FORPRIDECOM pulping process, which features a new cooking formulation uuu ,,.t,uuccs noi »my a h.gh-quality unbleached chemical pulp tor a wide range 1 b,Cachcd PU PS for makin fi papers.nanirVh I he pulps T "^produced ^f' from the process ' possess properties« • comparable^ spccialiVv to those prepared from the other well-known alkaline pulp.ng processes. However a main advantage of this new pulping process is thai the potash salts in the speni liquor, combined with the extracted organic compounds of the fibrous material are directly recovered after the cooking cycle and can be utilized as fertilizer No pulp.ng effluent ,s wasted, and the dangers of environmental pollution'are minimized. * aiL BIBLIOGRAPHY A new process of producing high-grade chemical pulp. Letters paten, no. 91 54 Bv J. O. hscolano «/M/ others. Philippines Patent Office 1975 Bawagan, P^ V Pulping abaca fibers for export speciality papers. /„ Selected abaca AÍaca ¡97K ^^ ^""^ lnte•«•«« documentation Centre on Bawagan, P. V. and LO. Escolano. Kraft pulping of some Philippine wood mixtures and their pulp handsheet qualities. Philippine lumberman (Philippines) 13:2:20-27. harf^ndrUJS!r and Papt;rmakine of naturally-occurring mixtures of Philippine hardwoods. Philippine lumberman (Philippines) 9:2 : 76-83. December 196"> and PaPCr rCSCarCh at review^MR^Rwf HJRPRIDk digest• ^(Philippines)•? 6: I • I6-"M 1977 ^RPRIDECOM: A Escolano, J. O. and E. P. Villanucva. Abaca for pulp and paper. FORPRIDECOM technical note no. 140. Philippines, 1974 MarnLr M' F°Tyuar- dcvel°Pment Plan Philippines. National Economic and Development t Authority, 1974. mgUrl R L^arket ír abaCa and °thcr fibers- '" Ah• and other perennial crop McJ ,' Ph,,ipP,ne Councii for Agricultural Research, 1974. pp 73-79 NSSC pulping and paperboard making of , hardwood mixture. Bv J. O. Escolano and others. Philippine forests (Philippines) 5:2/3'16-18 1971 Parchment paper from abaca fibers. By E. P. Villanueva and others. Philippine forests (Philippines) 4:1:27-34, 1970. «'//""< jonsis Philippine pulp materials for newsprint. By J. Ü. Escolano and others. Philippine lumberman (Philippines) 18:11 25-30 1972 ««/'/'»« Pr°Zli^hZ for eXtTtÌOn and/rw-si"g fih-s f«>m fiber-bearing materials of agricultural and minor forest products origin. Letters patent no. 9200 Bv E C Armo and others. Philippines Patent Office 1975 Proximate chemical analysis of fibers from seven abaca varieties. Bv E. U. Escolano and others. Philippine lumberman (Philippines) 22: 12:20-26, 1976. Proximate chemical composition of the various parts of the coconut palm. Bv P C branca and others. Philippine lumberman (Philippines) 19:7:20-23, 1973. ' Short-cycle sulfate pulping of abaca chips and fibers at low alkalinity. Bv F P Villanueva and others. Philippine lumberman (Philippines) 17:7:28-33, 1971. Tamolang, F.N. Coconut trunk utilization research at FORPRIDECOM Paner prepared for the Seminar on Coconut Processing and Product Development Los Banos, Laguna, Philippines, 1977. í.s re d Paper P P;« uij|.za|¡on ()f „,„,„„, ,runk and othcr parts ,n the Ph.bppmes. N.SDB ^J^VZta^t^^ Pape- P--P. "• <«*«"<-' (P _^ ÏÏÏ^SÎ rnalenaMor ££ pacRaging; abaca fibers. N.S'O« ,. **v yoMrnn/ (Philippines) 3:1:50-56, 1978. The pulp and paper industry in Egypt M. A. El Ebiary' HISTORICAL DEVELOPMENT The ancient Egyptians used papyrus paper as far back as 4300 B.C. Indeed, the word "paper" comes from papyrus, which is composed of layers or strips from the stem of the papyrus reed, pressed together. At the beginning of this century, the first mechanized paper mill in the Middle East opened at Alexandria with one machine. Its output was some 10 tonnes per day (t/d) of lightweight solid board for small boxes. In 1922, a new machine of slightly larger capacity was added, followed by another in 1953. Since then no expansion has taken place at this mill. There are no plans to modernize the existing equipment, but at some future date it may be replaced by a new installation. The next development was the foundation of the National Paper Company mill at Tabia, east of Alexandria. The reasons for selecting this location were the proximity of rice-growing areas and the port of Alexandria, as well as the possibility of discharging effluent into the sea. Two paper machines and a straw-pulp plant started up in 1940. New paper machines were added in 1945, 1961 and 1968. In 1965 and 1970, reconditioning and rebuilding of some of the machines took place. A sixth machine was added in 1977. In 1945, the Société Industrielle du Moyen Orient (SIMO) was founded north of Cairo. This mill started with three paper machines producing wrapping paper. It was complemented by two small plants for air-dried grey and coloured boxboard. A sixth machine is now under construction. That machine is intended to produce 50 t/d duplex folding board. In the early 1960s there was an important jump in production capacity. In 1961, the sack kraft paper mill in Suez and the writing and printing paper mill Rakta near Alexandria came on stream. The Suez mill used imported kraft pulp, and was supposed to use a part of the unbleached bagasse pulp from the mill in Edfu which would start a few years later. In 1967, the decision was made to dismantle the Suez mill owing to military action in the Canal Zone; the installation was re-erected at the National Paper Company mill at Tabia. The Rakta mill started in 1961 with a bleached rice-straw pulp mill and two paper machines for wood-free writing and printing papers. In 1967, a 30 t/d •Chairman, Rakta Pulp and Paper Mills, General Company for Paper Industry, Alexandria, Egypt. ?o TT chemi-mechanical rice-straw pulp line and a waste-paper pulping line were added to supply furnish for a 50 t/d multilayer board machine which was installed. A year later, a third 60 t/d machine for writing and printing paper was added. . . A new bleaching plant for 100 t/d of bagasse pulp started up in 1970. It was designed to work in tandem with the existing rice-straw line. In 1976, the two oldest paper machines each were modernized to produce 60 t/d of writing and printing paper. A new additional rice-straw pulp mill with 90 t/d capacity is now under construction. The bagasse bleaching plant will be modified to handle this quantity of rice-straw pulp. The last new enterprise in the pulp and paper field was the Edfu bagasse mill. It started operation in 1965 and was designed to produce 60 t/d of unbleached bagasse pulp. . From the above it is clear that the bulk of pulp and paper now produced in Egypt is made with relatively modern equipment. EXISTING PRODUCTION AND CONSUMPTION OF PAPER The existing domestic paper industry produces about one half of the paper products currently consumed in Egypt (table I). Current total paper consumption in Egypt is 300,000 t/a or 7 kg/a, per capita and is forecast to rise to some 567,000 t/a by 1985 (table 2). TABLE 1. PRODUCTION OF PAPER IN EGYPT (1978) Basis Production weight rate Type (g/m*) (t/a) Writing and printing paper 40-100 48 000 Manifold 30 2 000 Duplicator (stencil) 70 2 000 Coating base 70-80 1 500 Greaseproof 40 1000 Kraft and kraft wrapping 40-150 15 000 Sulphite wrapping 55-60 1 800 Corrugating medium 130 5 000 Kraft and kraft liner 130-200 5 000 Cover paper (all grades) 130-350 15 000 Duplex board 250-550 14 000 Textile cone paper 270-^00 10 000 Wrappings (low grade) 110-240 25 000 Heavy boards (low grade) 600-1 000 6 000 Total 151 300 I ABl.H 2. DOMESTIC CONSUMPTION OF PAPFR AND HOARDS (Thousands of tonnes per annum) Type !')?.< IV7-4 I97S l>>76 / W0' IW<¡a Printing and writing 46.9 53.7 75.7 87.7 124 170 Industrial (including corrugating, liner. sack etc.) and board 122.ft 126.6 145.0 156.0 209 302 Newsprint 26.9 41.6 49.0 60 75 | 46 7 Magazine 3.0 12.0 12.6 15 20 "Based on an estimated 8 per cent annual increase The papers produced are printing and writing papers, wrapping papers and boards. No newsprint is produced. Raw materials used are rice-straw, bagasse, waste paper and imported long-fibre pulp. There are 15 paper mills and one market pulp mill. Nine of the paper mills are small, primitive, privately owned mills with capacities ranging from less than 1 t/d to 16 t/d. Combined production is only 57 t/d. These small mills produce the lowest grade of coarse wrapping paper and chipboard and are marginally profitable. The production of the six government-owned paper mills is 440 t/d or close to 90 per cent of the total p-oduction of paper in Egypt. RAW MATERIALS FOR PULP AND PAPER The principal raw materials available for the production of pulp in Egypt are bagasse and rice-straw. These short-fibre raw materials produce pulps similar to hardwood pulps, and consequently, there are limitations as to the types of papers that can be produced using a high proportion of local raw materials. Long-fibre softwood pulp must be imported to blend with the locally produced short-fibre pulps for the production of most types of paper. Both rice-straw and bagasse materials are available in far larger quantities than are being used today. Rice-straw Egypt is a major producer and exporter of rice. The area planted with rice amounts to about 420,000 ha. Annual production of white rice stands at some 270,000 t/a. The corresponding quantity of rice-straw reaches approximately 1 million t/a. Table 3 shows the areas of crops under cultivation which, in principle, could be considered potential sources of paper-making fibre. The mill at Rakta, established 1960, is probably the world's largest and leading rice-straw pulp mill. Rice-straw is also used by the National Paper Company and by SIMO, Total consumption of rice-straw for pulping is at present 100,000 to 110,000 t/a; another 10,000 t/a of rice-straw is being used by the soft-board plant in Dam ietta. TABI H 3. ARFAS OF CROPS UNDER CUL- TIVATION (1478) A ri'ii ( rop (hai Rice 442 260 Sugar-cane 60 900 Wheat S85 500 Cotton 565 300 Flax 22 680 Corn (maize) 768 600 Rice-straw can be easily pulped, and an alkaline cook is considered the most suitable. There is, however, no proven process for recovery of the cooking chemical, and this is a severe handicap. It means that the black liquor, containing about one half of the straw quantity and all of the cooking chemicals, must be dumped. If chemical recovery were possible, dissolved organic material could be recycled, and pollution would be much lower. The quality of rice-straw pulp can vary considerably, depending on the amount of leaves and sheaths that remain in the straw after cleaning. These parts of the plant contain mainly non-fibrous cellulose. The result is a pulp that drains very slowly. To a certain extent, this is not undesirable as sheet formation may improve. On the other hand, it seriously limits paper machine speed. Effective removal of sheaths and leaves would reduce pulp yield. Methods used today at Rakta are rather effective. Hence, yields are still reasonably high, but the pulp waters very slowly. This problem manifests itself on vacuum filters in the pulping and bleaching operations and on the paper machines. New high-yield varieties of rice tend to be shorter. Furthermore, the piant has more leaves. This is very undesirable for pulp- and paper-making operations based entirely on rice-straw Another limiting factor is the high silica content of rice-straw, which causes difficulties when attemping to recover pulping chemicals from an alkaline cook. It is resposible for very high black liquor viscosity at the concentrations needed for combustion and for inadequate sludge settling after causticizing. Better removal of leaves and sheaths before pulping would definitely be a- step in the right direction, since they contain three to four times as much silica as the stalks. Unbleached semi-chemical rice-straw pulp made by soda or by a lime cook yields fibre with good stiffness properties. It could be used to produce corrugating medium of acceptable quality, but paper machine speed would be low, cwing to slow stock drainage. Bagasse Bagasse consists of the remnants of sugar-cane stalks from which the sugar-containing juices have been extracted by crushing. For decades it was used exclusively as fuel in the sugar mills. Small and older mills need all of their bagasse for the generation of process steam. Larger and more modern mills have a surplus of bagasse. In Egypt, six sugar mills were in operation in 1976; they and their bagasse outputs are listed in table 4. TABLE 4. BAGASSE OUTPUT OF SUGAR MILLS IN EGYPT IN 197ft Amount of sugar- Moist Height Dry weight of Residual cane crushed Proportion of ihr bagasse Moisture thi bagasse sugar (thou sands of of bagasse (thousands of content Uh oitsands ol ( miteni Sugar mill tonnt s) Ipi rent) tonnes) (per cent) tonnes) (per cent) Abu Qurqâs 547 33 180.5 54 83.0 4.6 Nag Hammâdi 1 364 35.3 484.3 54.6 220.3 5.3 Qus 741 34.3 254.5 52.6 120.6 5.4 Armant 882 30.8 271.5 50.8 133.5 6.1 Edfu 760 33.2 252.5 51.1 123.4 5.1 Komombo 1 090 34.9 380.7 52.4 181.2 5.2 Total 5 383 1 824.0 862.0 One sugar mill, Edfu, has a relatively small bagasse pulp mill attached to it. The present output of this mill is about 40 t/d, althought the availability of bagasse from the Edfu mill would be sufficient for a pulp mill of 100 to 140 t/d. The price of bagasse to be charged to a pulping operation is essentially a direct function of the quantity of oil that is required to replace the depithed bagasse. It is economically advantageous to return pith to the sugar mill for use as fuel. The Edfu pulp mill bales and stores moist depithed bagasse. Pith is returned to the sugar mill as fuel. The cost of depithed, baled bagasse is currently $ 11/t. Bagasse could be available in large quantities to the Egyptian pulp and paper industry. The present sugar-cane production, if completely converted to pulp, would yield more than 200,000 t/a of bleached pulp. In addition, the cultivation of sugar-cane has grown steadily over the years, and the Government is planning further increases. Bagasse is composed of two distinct cellular constituents: fibre and pith. The fibre fraction of long, strong fibre bundles from the rind and from fibrovascular bundles within the cane stalk. This fibrous fraction is an excellent raw material for the production of pulp and paper. The pith fraction consists of thin-walled non-fibrous cells that contained the sugar juices before crushing. These pith cells are of no value for the production of pulp and paper. In fact, their presence is detrimental to the production of pulp and paper, and they must be removed prior to pulping. Furthermore, there is a dense non-fibrous waxy epidermal material which is of no paper-making value. In addition, bagasse contains residual sugars and other water solubles and it invariably contains appreciable quantities of dirt, stones and other foreign matter that enter the crushing mill with the cane. Rather significant variations in the composition can occur, owing to differences in cane variety, climatic conditions, time of cutting and mill operating conditions. The first step in a bagasse pulping operation is pith removal. This is now usually accomplished in two stages. In the first stage, moist bagasse in its natural state of approximately 50 per cent moisture is shredded and screened in a rotary mill. The pith, along with some l'ine libre, are rejected ami returned to the sugar mill. The accepted fraction contains about KO per cent fibre and 20 per cent pith. Part of this fraction is conveyed to an area where it can be stored for several months for use when the sugar mill is not in operation Most authorities agree today that bagasse should be stored on a slab in bulk The other part of the accepted fraction is conveyed to a wet depithmg operation where the fibre content is raised to ')() per cent. The washed fibre is drained, pressed, impregnated with alkaline cooking liquor, either soda or kraft, and fed to a continuous digester. From this point on, conventional washing, screening and centrifugal cleaning equipment are used to produce finished pulp. By varying the amount of cooking chemical and the digester dwell time, all grades of pulp from semi-chemical to bleachable can easily be produced. PAPER MAKING A combination of bagasse pulp and rice-straw pulp could offer certain advantages. It would be possible to use a high quantity of short-fibre pulp while maintaining good drainage rates. The formation and sheet properties would also be good. Also, although neither dry strength nor initial wet strength can be increased with modern paper machines, problems with low initial strength can be overcome with closed draws from wire and through the press section. Furnish composition for making various papers using rice-straw, bagasse and imported pulp in various combinations and proportions are shown in table 5. TABLE 5. FURNISH COMPOSITIONS USING RICK -STRAW, BACIASSI AND IMPORTED PULP {Percentage) Rice- siran Ramasse Type of paper Unbleached Bleached I 'nbleached Bleached Imponed Wood-free printing and writing - < 80t - £ 90 £10 Bleached Bristol board - - - 50-100 0-50 Bleached Tissue - - - 60-90 10-40 Wood Lightweight paper, manifold - < 60 - - ^ 40 Wood Glassine, grease-proof 30-90 30-90 30-90 30-90 10-70 Sulphite Groundwood printing and writing - 20-50 - 20-50 20-40 Wood Newsprint - - 70-80 20-30 Bleached kraft Duplex and triplex 30-80 30-80 30-80 30-80 20-70 Wood Wrapping and bag paper < 60 — < 85 = 15 Waste paper or wood Cement-sack kraft paper - - < 70 ^ 30 Kraft Corrugating medium < 100 - < 100 ^ 0 Waste paper or wood Coarse board S 80 - < 100 è 0 Wood Testi ine r 50-80 20-50 Kraft However, as table 1 shows, some grades of paper cannot be easily manufactured with only non-wood fibre raw materials. These are: (a) Cement-sack kraft paper. The best kraft paper, suitable for cement sacks, is made from softwood pulp. With a Clupack installation, a high bagasse pulp content could be achieved; (b) True linerboard, which needs softwood kraft pulp; (c) Newsprint and magazine paper. Newsprint especially requires groundwood. The only substitute to produce true newsprint appears to be chemi-mechanical bagasse pulp. The presence of wet-strength paper in waste does not yet create operating problems in Egypt. This is largely because the paper producers themselves use little or no wet-strength resins. De-inking is not yet practised in Egypt. This could provide a new source of good-grade fibre, but the economics of the operation require examination. FUTURE PLANS FOR THE PULP AND PAPER INDUSTRY IN EGYPT Forecast for demand for pulp and paper in Egypt are more than sufficient to justify the cont uction of a number of new mills. Future plans can be placed in three categories: (a) Modifications and additions to existing mills to optimize their production; (b) Smaller projects suitable for private owners; (c) Major new projects. The first group consists essentially of projects to overcome technical and production problems facing existing mills in order to improve their operations. 0*ÎMO The experience of a developing country of Africa V. L. Moor thy* Introduction The $50-million Pan African Paper Mills project was sponsored by the Government of Kenya, the International Finance Corporation of the World Bank Group and Orient Paper Mills Ltd., India. Private financing was made available by a number of banks: the African Development Bank, the Citibank of New York, the Development Finance Corporation of Kenya Ltd., the East African Development Bank, the Industrial and Commercial Development Corporation of Kenya and the Industrial Development Bank of New York. In addition, the Export Development Corporation of Canada, the Export-Import Bank of the United States and Lazard Brothers and Co. Ltd. of the United Kingdom arranged loan finance for the purchase of machinery. Orient Paper Mills provided technical and management services to the new company. Thus, the mill is a true and fine example of international co-operation and, in particular, a show-piece of co-operation between the developing countries, India and Kenya, working on a viable industrial venture. Pan African Paper Mills was formed in 1970. Construction of the mills at Webuye, about 20 miles (32 km) west of Nairobi, began in 19^2 and was completed in late 1974. Capacity trials were started in November 1974, and by January 1975 the plant was on stream. The rated capacity is 45,000 tonnes per annum (t/a) of cultural and industrial papers. Review of alternative technology Range of technical options In the selection of appropriate industrial technology, it was found that, among the various pulping processes, the conventional sulphate, of kraft, process is versatile in teims of raw materials as well as the range of end-products. On the one hand, fine writing and printing grades of bleached paper were to be manufactured. The raw materials available in the country are pine, cypress and eucalyptus. Judicious blending of these fibres was intended to * Production Manager, Pan African Paper Mills (EA) Ltd., Webuye, Kenya. 43 44 obtain the required properties in the end-product, based on laboratory and pilot-plant studies contucted in India prior to project implementation. Market study and pricing In determining the capacity of the mill, a thorough market study was conducted as early as 1968 by a consultant firm in the United Kingdom of Great Britain and Northern Ireland. Further studies were conducted by Orient Paper Mills and the capacity of 45,000 t/a was decided upon. Local consumption was estimated at 70 per cent of capacity, with the remaining 30 per cent providing exports. Area development The paper mill brought an economic transformation to a rural situation on a scale never before seen in Kenya. From a typical village of no more than 500 persons at the inception of the project, the town of Webuye in the Western Province has, over the last few years, grown into a major commercial centre with a population of more than 20,000 centred around the paper mill. Besides providing direct employment for about 1,500 persons, the mill has created indirect employment opportunities for about 4,500 persons in reafforestation programmes, transport of materials, and auxiliary services. Assurances from the Government In any developing country, the Government must show keen interest in a large project and provide facilities and support. The Government of Kenya extended the following assurances: (a) Exemption from import duties and refund of all customs duties in respect of imports of materials, equipments, machinery, spare parts and fuel; (b) All exchange-control approvals required for the completion and operation of the project were granted, and necessary foreign exchange was made available for payment of commitment fees, interest and the principal amount of loans and dividends on the share capital; (c) The provision, without capital cost to the company, of a housing estate with 800 houses for the company's employees; (d) The creation of the necessary infrastructure for the development of the township including roads, water system, hospital and lighting; (e) The introduction of a system whereby no paper can be imported into Kenya unless a "no objection certificate" is issued by the company. Mill facilities The facilities of the mill encompass batch digesters; a 100 tonnes per day (t/d) bleachery; two 75 t/d paper machines, a boiler and turbo-generator of adequate capacity for the plant to be self-sufficient, a captive electrolytic plant for the production of caustic soda and chlorine, a chemical recovery system, a lime-recovery kiln and workshops, water-treatment and effluent-disposal facilities. 45 Forestry and fibrous raw materials Wood supply Kenya's potential for the low-cost production of industrial wood is one of the main reasons behtnd the Government's extensive forestry programme The pulp and paper mill obtains its wood requirements from forTpZta.bn situated at a distance of 60 to 90 miles (95-145 km) from hemi 7e ofPePurc~ COnSUmP"°n iS mVm m3/a °f Pine' <*<• •"" »• t-mmes Establishment of plantations and growth rate A novel reafforestation method has been adopted in Kenya called agr,-s,lv, plantations". After clear-felling a block, the area is given ,o farmert on ease, free „f charge for a period of two years. The farmer gTw maizeZh C a aS ,aPle P an S are immediatemme e area.aZ î,It is ,hthe responsibility ^L ?* of """"> the farmers ' ' to take « care of'" the< Äo ^^T """ "" P'an' " ~» —*-* '* f" The costs of plantations established by the Government are recovered bv royalties (stumpage) charged to private concessionaries when h es,"»; the Plant ,,o„St As an essentially commercial activity, Kenya's Lveno• of .ndustnal forest plantations, once fully developed, could be «"andalk sel -sustaining, and the cos, of maintenance and replanting aftenclear fei inL me, from income realized from the sales of standing timber 8' Pulp wood logging and transport The mill's round-wood requirements are me, by totally mechanized loeaine operations based on the handling of long fogs, which are considered to bf L mos, economic for ,he situation. Felling is done with power chain saws in accordance with a predetermined plan established for each planta Ln n £?Ärskidder efficiency- "•*• - »«-« is s Hauling ¡s done direct from the forests to the mill site with heaw-dutv S ofTm^O ,o„8neWayp'°8gin8 *"** ^ «**» ^ * «•» <Ä>' we gm ot some 30 tonnes. ExperimentsUnloading are also atunderthe way to obtain wood hv S^äÄ**"* -•"-"- Wood preparation and pulp manufacture Wood preparation 46 a stringy bark, a rine-tvpe debarl^r »,o t ¿ barker has provision forco^r";^•"d'„ * .he mos, su.table. Th,s r,ng with .he barking knive/on Ä feed side" °" "* ""M S'des "f "* d.r. pick-up is experienced in oJen ni^T " * I?"""""1 H"WK'- *« and cn,ps arc moved by be„ •^^Zt^^;'^ •e Pulp mill (unbleached) »st,, less maintenance, assurance oc2 u ,v in „ Î^ SyS'em arc: '— produce various paper qualities. cc""mmyln Production and flexibility to Bleach plani chlorine-alkaline X^^Z ^T?"«*«* «he s.ra,gh, sodium hypochlorite Äi7«Ä, — (CEHH) Se"uence wi<" and caus g.v,ng an end-brightness of SWr cem Ph T"T '¡c extraction. ,b aching was no, considered became .he „i,^? Pl"P' Chlorine dí•°c - »-. .onnage and because „ £ £."t^^*^ ** Cai«/«- chlorine plant A caustic chlorine niant of n t/A regarded as economically v ab e HoweveT'c "í CaPadtV is n0rmal|y « : COnS d erln international transport and the fluc.uaZ n , f' u « «* rising costs of ? chemk small captive plan, for ,he Zte 02 1°' ^- ¡» "as felt that a Admittedly, fixed costs on .his Xtarr^IT, „T be WOr,h ¡»«««¡"g. h.gh total cos, of production. Ho" M ^f,?"•«' to a" <"«•" Currently, the Government wishes to exnanri t ? he deC'SÌOn was P">P«- hydrochloric acid and chlorine produce mthf P a"' '° ""P^ caus«c »da. Diaphragm cells have hZ produf's *° th« local market. laws in KPenya^n^;:: br ;X ÍO ^ "" "i* "—.»«««0- co m u 10to,5 er ce cells). Caustic purity ¡s compara fvH. .P "t lower than mercury nevertheless acceptable foímosfuseT * """ dÌaphra«m ce"s "ut is M contea S^TZTH ^ s r • ^ sal. has high soda-ash has, however, the J^Jofn^XZ^ "" """ ^^ " ^¿^^r^^^rV- —ed, mainly to consumption, both as ^¿£OZ?£££ £ * captive Paper manufacture and marketing Paper manufacture Prior .o the operation of the Pan Africa„ Paper M¡1)s ^ ^ 47 imported all of its requirements of paper and board, whether for packaging, wrapping, or writing and printing grades. However, the packaging industry was well advanced, with sophisticated, high-speed converting and printing machines. In order to satisfy the needs of quality for these machines and at the same time keep operation and maintenance as simple as possible, the selection of stock preparation plant, paper machines and other finishing equipment was based on the following principles: (a) Equipment had to be rugged, require little maintenance and be simple to operate; (b) Wherever possible, low-energy systems were selected; (c) Capital costs had to be kept down by resorting to simple design and proven conventional equipments, but without sacrificing flexibility of production capability over the entire range of products. There are two turbine-driven paper machines: one for unbleached and one for bleached papers. The unbleached machine manufactures sack kraft, kraft liner, bag kraft, machine finished kraft, gumming kraft and unbleached and semi-bleached printing. The substance range on this machine is 40 to 300 grams per square metre (g/m2). The second paper machine, which is producing varieties of fine bleached papers over a wide substance range, was the real challenge. For example, this machine is now making four completely different categories of papers from 38 to 225 g/m2. To meet the local demand for quality paper and to cover the entire range of categories as far as possible, considerable research had to be done both in pulping and paper in order to evolve the mill's own norms and conditions for optimum production of each individual quality. In the area of stock preparation, double-disc refiners were chosen because of their lower power consumption and easy maintenance. Marketing To plan paper production in a developing country, the following important factors must be" carefully identified and ensured: (a) The flexibility of the domestic market to adapt to the commodity produced; (b) Export potential; (c) Unequivocal support from the Government. Problems of marketing posed a great threat in the first two years of production, as heavy imports were continuing. At this juncture the Government came to the rescue, and the "no objection certificate" system was introduced. This strong backing to industry by the Government was of paramount importance and paved the way for successful production. Furthermore, the product range had to be diversified to meet local consumption in as many qualities as possible, and the substance range of manufacture had to be streched over wide limits, for example, on one machine, 40 to 300 g/m2 and on the other 38 to 225 g/m2. In addition, a scheme called "re-exporters' rebate" was introduced to enhance foreign marketing and 48 stimulate the local converting industry. This scheme gives special rebates on paper purchased locally but destined for re-export. A similar plan was implemented, called the "educational rebate scheme", to encourage local industry to print textbooks for education. Export markets have been developed by constantly improving quality so that products will match international standards. Today, Kenyan paper is regularly exported to numerous countries in Africa, Asia and the Middle East. During 1977, some 15,000 tonnes of paper (30 percent of production) was exported. Utility service Water The character of the river water used shows the presence of heavy metals in the reduced state. As the mill is designed to make fine bleached-grade papers, a simple and ingenious system of static aerators is provided without any energy consumption. The heavy metals are thus oxidized and precipitated out of the water at the clarification stage. A solids contact clarifier was chosen owing to the low turbidity of the river and for conservation of flocculation chemicals by partial return of floe sludge. Conventional rapid sand filters were also provided. Steam and power A medium high-pressure boiler of 42 bar was chosen for steam production. The turbine is a reduction-geared unit with a single helical gear. The alternative is air cooled and has a brushless system with electronic excitation and voltage regulation to keep the maintenance factor low. Chemical recovery In the selection of multiple-effect evaporators, ease of operation and maintenance of the equipment was kept in mind, and thus an in-between concentration of 48-50° Twaddell (tw) is taken out of the evaporators; this is coupled with a direct-contact evaporator to achieve a firing black liquor concentration of about 65° tw. The furnace is a conventional chemical-recovery one. The precipitator is of the low-temperature type with a modified wet bottom. This has eliminated the agitator and its associated maintenance problems. In the causticizing section, clarifier-cum-storage tanks are provided for green liquor, white liquor and the lime-mud washer. The open-air type of equipment in this area was preferred, mainly owing to its simplicity and to lesser problems with corrosion. The clarity of white liquor from the open-air type of clarifiers is within 100 parts per million (ppm), sufficient for use in a pulp mill. Limestone in Kenya is of comparatively poor quality, with high contents of iron, aluminium, silica and inerts. This factor was taken into consideration when determining the design capacity of the limekiln. The lime sludge is also quick settling, and provision has been made in the discharge line and pump capacities of the clarifiers in the causticizing section. 49 Environmental protection An ecological survey of the middle and lower Nzoia river valley was conducted, and the scientific data and field observations of various disciplines were brought together to delineate and analyse the main variables of the environmental quality in this part of western Kenya. A water quality plan was then established for the receiving water, stating all its beneficial uses. This formed the rationale for setting standards for waste discharge and for a treatment sufficient to protect the beneficial uses of the water supply. Discharge water quality requirements were fixed by the Government, and the mill's effluent-treatment facilities have been designed in such a manner that the treated water characteristics are well within maximum permissible limits. The facilities for waste water treatment at the paper mill are of proven conventional design and include primary clarification, followed up through secondary biological treatment by the aeration ponds system (70 acres-28 ha) of land constituting four ponds; the first two have an area of 30 acres (12 ha) and are biological ponds with six surface aerators of 75 horsepower, each capable of treating 10,000 kg/1 of BOD). Detention time in the first two biological ponds is 13 days, and the total detention period for effluent is over a month. Sludge lagoons are also used for settling the underflow sludge from the clarifier. After drying, the sludge is either disposed of as land fill or incinerated. The choice of the aeration pond system for secondary biological treatment ideally suits the climatic conditions of the site as well as land availability, with suitable contours for gravity discharge throughout. Engineering Mechanical The following principle dominated equipment selection during the project: (a) Simplicity, sturdiness and easy maintenance, for example, totally scaled units were avoided wherever possible; (b) Direct drives with gearbox and flexible coupling were preferred, as they work even with slight errors of alignment; (c) Wherever possible, drive elements were used that could be taken out without disturbing the main parts (motor or pump base), for example, universal joints or Hardy Spicer couplings. The advantage is that they can take more angular and axial misalignments, which are bound to happen with limited skills in manpower; (d) Metallurgy is given high emphasis; no compromise was taken in this area although it meant a higher capital cost; (e) The lubrication system should, wherever possible, be of the "centralized oil" type; (f) Standardized pumps and couplings of limited types and sizes should be selected. While duplicate equipment has been reduced to a bare minimum, the .ï(> inventory of spare parts must be rather abundant, and planning for them is done at least 12 to 18 months ahead. Furthermore, workshop facilities should be soundly based on the following guidelines: (a) All major equipment should be able to be maintained locally; (b) A lathe machine capable of coping with the longest and largest of the appliances in the mill should be on hand; (c) A shaper and planer i .achine of similar size, as well as a milling machine, should be available; (d) Special metal-spraying equipment should be stocked for metallizing and building up worn parts without distortion. Electrical In the design and selection of electrical equipment, the following points were paramount: (a) Equipment is kept more conventional, simple and sturdy. An example is the salient-pole, air-cooled brushless alternator, which facilitates easy dismantling, inspection and repair. Similarly, cable insulations are of higher temperature rating and insulation value than conventional requirements for the service they supply; (b) Less automation of controls, giving a better conception of different operational procedures is preferable. For example, variable-speed electrical drives are not provided for brown stock washers, bleach washers etc.; instead, mechnical drives with PIV gears are used. The paper winder is provided with a mechanical brake back-stand, thus eliminating the extensive electronics of regenerative brake winders. Non-computerized controls are employed for boilers and paper machinery; (c) Additional safety interlocks are used to minimize possible damage by improper operation. For example, chippers fitted with precision sensing of synchronous time trip out at the slightest malfunction of synchronizing conditions and they are also determined electrically. A memory circuit is also provided to prevent re-starting before the predeterminded cooling time; (d) An adequate inventory of spare parts is kept on hand to cope with possible damage by incorrect operation and coverage for delivery delays. Instrumentation and controls This is the area where the lack of skilled manpower presented the most problems; the instrument requirements of the mill had to be very carefully planned. Depending upon the application and precision required, pneumatic, electric-electronic and hydraulic instruments are used to the maximum extent. Their components (for example, orifice and booster relays etc.) are simple in design, dependable, cheap and easy to maintain. With limited manpower skills, sophisticated instruments are not desirable because it is possible that the use of a potentially valuable control system must often be abandoned because of a lack of proper understanding of its maintenance as well as operational needs. Large instruments are preferred to small ones because of easy servicing s/ without affecting the process. Most of the control valves are of simple design The eccentrically rotated plug design of the camflex-typc control valve and the rotary shaft control valve with a V-notch ball were chosen tor many functions not only for economic reasons but also because of their suitable control characteristics and tight shut-off. Electronic instruments are in use where accurate direction is required, such as in the control of the speed of paper machine turbines, the basic weight valve of the paper machine and in the recovery bioler turbine for controlling the furnace pressure. Hydraulic systems were chosen for paper-winders, re-w.nders, the log-conveying system in the wood room and log-debarking units. Building design Owing to the mild to tropical climate, building designs could be kept simple, with maximum utilization of locally available material. Reinforced concrete buildings with structural steel columns, and flat roofs with pre-cast sections were selected This choice reduced the cost of construction and, to a certain extent, ventilation problems. Spread footing-and-pile foundation and bored //, suu cast concrete piles were used for heavy and settlement-sensitive buildings. For grouting, dry-packed Portland cement was chosen in preference to non-shrinking special grout materials, and the results were positive. TRAINING Training is perhaps the most important aspect of a pulp and paper project in a developing country. Paper technology and allied operations were new to the country/and no training facilities were available in any of its educational institutions. Therefore, to generate necessary skills, an extensive training programme was drawn up at the planning stage, and continues in effect. The basic features of the programme are: Training of Kenyans in pulp and paper mills in India for taking over supervisory positions Training for workers in Kenya In-plant vocational training in the mills and in the logging division Instruction under the Industrial Training Act Training of craft and technical apprentices Overseas training for senior Kenyan operational staff Under the pre-operational training programme, 28 Kenyans were sent to India for periods of 18 to 24 months. Most of these ex-trainees are now f0reiFor" preparing the local work-force, training began with people selected from the contractor's labour force. Related instruction concerning the various installations was given during the erection period. Then screening was done, and suitable candidates selected both for operations and maintenance. Subsequently, the Director of Training allowed the mills to designate them as -indentured learners" for a period of 18 months to be trained in the process, .52 Utility, instrument or drawing sectors or any other trade that was not covered under the Industrial Training Act. By this method, a core of about 100 persons were prepared for semi-skilled jobs. Positions such as electricians, fitters, turners and machinists are covered under the Industrial Training Act. Under the Act's Craft Apprentice Scheme candidates are sent by the company to the National Industrial Vocation, Training Centre, Nairobi (NIVTC) or the Mombasa Polytechnic and Industria Training Centre, Kisumu. In-plant training is given within the mil. and theoretical training is covered at the institute in a three-year course for candidates holding Form IV Technical. Examinations are then conducted by the Directorate of Training for preliminary, intermediate and final levels The final evel certificate ,s called Craft Test Grade i and the holders of this certificate form the core of skilled workers in the engineering departments For logging operators, a separate scheme of training was prepared for handling and operating of logging equipment and was conducted by a logging consultant firm in Canada as well as by the logging-equipment suppliers Supervisors are encouraged to prepare as external candidates for City and G*Tin lt,0nS and °rdinary and higher diP,0ma certificates in their sphere ofn wo k. Since institutions in Kenya do not offer courses for boiler and turbine operations, the company training school introduced a course in 1976 both for supervisors and workers and gave instruction in the operation of boilers h Ca W the centreë^fora^^C for City and Guilds^ of\ í""?'London ^ certificates ^ *in "° East Africa <** examination «Mir t«T! °P^rat,nS Per*onnel such as graduates and executive trainees are sent to pulp and paper technology courses such as those given in Scandinavia by the Swedish International Development Authority (SIDA) and the Norwegian Agency for International Development (NORAD). Programme of action Keeping in view Kenya's vast forest resources and its planned development of valuable long fibre, plans are underway to enlarge the Pan African Paper Mills in two phases. F 45 000 ïf In mir' thu paPer"makin8 faci,ities would be expanded from 45,000 to 60,000 t/a with a view to diversifying the product range This expansion would involve modifications to the bleached-grade paper machine particularly «n the press section, to achieve higher web dryness for reducing energy consumption in terms of steam and fuel oil, and incorporation of size press and auxiliary equipments for production of surface-sized and coated papers, and diversification of the product in order to cater to new areas of application. In the second phase, it is planned to establish a market pulp mill to manufacture bleached sulphate long-fibre pulp for export. The unbleached paper machine will also be modified to include the latest technology, particularly in the press section, so as to conserve energy. Mill production capacity will be increased to 75,000 t/a of paper. y New technological options will continue to be considered for further product diversification and application to new areas. Strategies for developing pulp and paper industries in developing countries A. D. Adhikari* THE SITUATION IN INDIA India entered the pulp and paper industry in an organized manner only towards the end of the nineteenth century. The mills which were set up at that time were all of the integrated type, utilizing mainly bamboo as the raw material With the increased production from 150,000 tonnes per annum (t/a) in 1950 to 960,000 t/a in 1977, there are visible signs that raw materials such as bamboo are becoming scarce. In the last decade the price of bamboo has more than doubled. The steadily decreasing availability of bamboo has caused many integrated mills to begin increasing their use of domestic mixed hardwood and a number of small mills have also been built in various parts of the country based on agricultural residues such as rice straw, wheat straw, kenaf, bagasse jute cuttings and other seasonal materials. Compared to capacities in developed countries, even India's 25 largest mills must be considered small. Nevertheless, the products manufactured with the technology currently available in India are good enough to meet the domestic requirements. This being the case there seems little reason for increasing capital investment to acquire more sophisticated technology. The more developed the technology, the lower the labour input and the higher the investment In a country where wages are relatively low, there seems little reason to cut costs by increasing investment and reducing labour. In India, therefore, a wide range of technology in the paper industry is available for capacities of 3 to 200 tonnes per day (t/d), using materials such a* agricultural residues, bagasse, bamboo and mixed hardwood. Employment per 1,000 t/a of production was as high as 75 people in mills set up earlier than 1950. For mills being currently established, the figure has come down to 35 per 1,000 t/a. In developing countries, no lower employment ratio than this is needed. On the basis of Indian experience, four technologies represent the present stage of technological development: (a) A chipping plant located where bamboo or wood is plentifully available, but the cost of transport of other inputs for further processing to pulp and paper is uneconomic; (b) A sun-dried pulp sheet and common paper or board plant based on * Managing Director, Ashok Paper Mills Limited, Jogihopa, Assam, India. S 4 agricultural residues. Suggested capacity is 25 t/d. It has been found that fertile agricultural land of 10 km2, growing two crops per year, can sustain a mill of this size If an efficient transportation network exists, the capacity can be higher. For making pulp sheet, it has been assumed that sun-drying is possible for 250 days per year. Employment would be 450 in the factory and about 500 in the field; (c) An integrated paper plant based on bamboo chips producing both medium grade kraft and white in four 25-t/d units. The plant would have a chemical recovery unit and an effluent of a quality that would allow its disposal on surface waters; (d) An independent paper plant using purchased pulp, domestic or imported. The capacity suggested is 25 t/d. The alternative is for a port area where pulp can be imported and converted into paper and be consumed in the vicinity. To promote the successful application of these technological options in developing countries it is suggested that national Governments adopt the following policies: (a) Reliable estimates of wood, bamboo, agricultural residues, bagasse and other potential raw materials should be available at regular intervals. Planting of fast-growing species yielding good quality pulps should be taken up; (b) Adequate infrastructural facilities for the integrated development of rural industry should be provided by national governments; (c) Power should be available at a concessional rate, and tax exemptions and transport subsidies are recommended; (d) The training of rural people should be organized and financed at a national level; (e) Finance has to be provide to the potential entrepreneur at low rates of interest; (f) Developing countries should also: (i) Earmark goods to be manufactured by developing countries, (ii) Relax tariff barriers in respect of goods and services from one developing country to another, (iii) Give preference to machinery from other developing countries if appropriate merchandise is available, (iv) Allow easy transport of goods through adjacent countries, (v) Promote bilateral and multilateral arrangements for efficient utilization of resources. THE PULP AND PAPER INDUSTRIES IN DEVELOPING COUNTRIES WITH PARTICULAR REFERENCE TO INDIA Raw materials Traditionally, softwood was the preferred raw material for making paper- grade pulps. Most developing countries are, however, devoid of softwoods. ss Hence the technology has to be oriented tor hardwood, bamboo, agricultural residues and similar raw materials. Bamboo, for example, is the principal raw material used lor paper making in India. However, in the context of depleting resources of this raw material, the technology for pulping hardwoods and agricultural residues is gaining momentum. At the same time, the use of agricultural residues presently used as cattle-feed or fuel in rural areas is either likely to meet resistance from the rural population or their price rises steeply, rendering them uneconomic as raw materials for the manufacture of paper and paperboard. The problems are illustrated by bagasse, which has long been used in sugar mills as the only fuel. As a pulp raw material, bagasse eliminates the harvesting and collection problems associated with many other fibre sources. Furthermore, it is found in good supply in areas where little or no native wood supplies for paper making are available. However, although bagasse is plentiful and available, it cannot, in any sense of the word, be regarded as a free material, since it is the main fuel used to supply heat for sugar-mill operations. Based on heat requirements for the mill and assuming good furnace efficiencies, an efficient raw sugar mill should be able to operate on about two thirds of the bagasse produced, leaving the other one third as surplus for other uses. Putting a monetary value on bagasse is difficult, but any realistic evaluation of the material must take into account such factors as current sugar mill practices, particularly regarding surplus bagasse, furnace efficiency and the neat values of bagasse and of alternative fuels, furnace efficiencies with alternative fuels and the monetary value of alternative fuels. The general trend in consumption of different raw materials for manufacturing pulp and paper in India is shown in table 1. TABLE 1 TREND IN CONSUMPTION OF DIFFERENT RAW MATERIALS (Percentage) Raw material /y.Sfl^y 1975 71> Bamboo 70 51 Hardwood 4 2K Softwood 6 3 Agricultural residues and grasses 16 12 Waste paper 4 6 These figures reveal a rapid increase in the utilization of hardwood. Paper production, consumption and trade In India, planned development of the paper industry began in 1951 when there were about 20 paper mills with a total installed capacity of about 150,000 t/a. Since then there has been rapid progress, especially in the second and third five-year plans. There are now about 25 mills with a capacity of more than 10,000 t/a and about 50 mills with less than 10,000 t/a, with a total Vi installed capacity of about 1.1 million t/a. The small mills account for 20 per cent and the large mills 80 percent of the total production. Wit n a nua average growth ot 7 per cent, it is estimated that by 1985 installed capTatv should be about 2.7 million t/a. capacity The relative position of developing countries ¡s indicated by table 2- 80 per cent of world production is from developed countries, whereas the developing countries account for only 20 per cent. TABLE 2. PAPER AND PAPER HOARD PRODUCTS BY REGION ( thousaiuh nf tonnes) Region Wrt / y North America 36 226 38 wi ; 58 914 60 881 65 325 Europe 19 621 25 h34 45 159 45 351 47 970 Asia and Oceania 4961 7 861 20 621 20 998 22 462 Latin America 1 192 1 656 3 712 3 835 4 252 Africa 178 288 892 943 1 017 World total 62 1 79 74 355 129 298 132 008 141 026 L. Following the oil crisis in 1973 there has been a strong recession in the paper market. For the last few years there has even been a buyer's market in it Developing countries have an in-built demand growth for paper arising mainly from educational needs of a large population base with a massive ¡literacy problem. The demand for newsprint goes up with the spread of iteracy Progressive diversification of industry and the growing need for various types of packaging materials as the economy expands further increases overall demand. In line with this, there is a wide gap in the annual per capita consumption of paper between the developed and developing countries: United States 267 kg Sweden 202 kg United Kingdom 140 kg Malayasia 20 kg China !okg India 2 kg Indonesia 2 kg Wood-pulp is a commodity of worldwide importance; in 1972 about 8 5 n 3) Mme share 40 pern°e r IZT?cent) of world íl trade ^ in paper " '"and ** paperboard ^ went^ ^^ to Canada, Roland ("early Sweden and the United States of America (table 4). Inspection of th se tables reveals that, owing to their present low production and levels of pe capita coumrie0"' e ,S a Very 8reat POtemial f0r Paper trade amon*the devel°P "8 57 TABLE 3. INTERNATIONAL TRADE IN PULP IN 1972 {Thousands of tonnes) Ixport Country Production Import 139 Brazil 1 029 146 102 Canada 19 091 106 Egypt Sf» 35 611 Finland 6 284 4 16 India 747 15 Indonesia 34 2 — Iran 26 13 47 Japan 9 458 807 Kenya 9 Malaysia 9 Nigeria 10 1 785 Norway 1 976 210 Philippines 63 31 7 Singapore 11 3 United Kingdom 357 2 190 2 237 United States 46 604 3 733 TABLE 4. INTERNATIONAL TRADE IN PAPER AND PAPER BOARD IN 1972 (Thousands of tonnes) Import h.xport Country Production 8 Brazil 1 367 250 9 515 Canada 12 699 347 6 Egypt 145 75 4 302 Finland 4 965 27 25 India 846 173 Indonesia 35 144 Iran 143 142 503 Japan 13 648 143 Kenya 8 71 11 Malaysia 18 179 Nigeria 10 41 958 Norway 1 348 98 Philippines 287 127 Singapore 5 135 Sweden 4 562 129 3 164 United Kingdom 4 338 3 054 247 United States 59 310 7 993 2 940 RECENT TRENDS IN MODERN PULP AND PAPER INDUSTRIES Coniferous woods such as balsam, fir, hemlock, pine or spruce are still the principal source of raw materials for the bulk of world production of paper and paperboard. However, in the context of depleting resources and rising demand, there is a gradual switch to hardwoods. Once considered as short fibred and hence unsuitable lor the paper industry, these hardwoods have become -in ,mp,»r an, source of raw material. ,„ many Asian countries, bamboo s e used as the principalmiH raw material.Bagasse In ,sIndia,bc ng nearlywili 5(1 per cent of naJer ŒZ5s anticipated thatZ^ bagasse'° and "f other \ agricultural ' residues ^ will'" -« play vital roles in the pulp and paper industry. Finally, lhere has been growing awLn s" ? he value ot waste paper. In many develop,, countries i, ,s expected h , its utilization is going to be as high as 30 per cent With regard to pulping, the kraft process still dominates the area of chemical pulping because of its distinct advantages over other nr^e se Continuous digesters have replaced the batch digesters in mos, of ,h large m range Iron. 52 to 75 per cent has aroused keen interest as a substitute for conventional pulps with yields of only 46 to 48 per cent su"s,"u"- '"' Polysulfide pulping has similarly created a good deal of interest in that the yield ,s about 4 ,„ 6 percent higher than conventional kraft pulping There is also great interest in whole-tree pulping as an important step to eo serve fibre resources. The concept of severing ,berree fromV s mP and processing every portion of i, above the ground-trunk, branches twigs and leaves-,„,„ a usable fibre source has become a reality. As the nd an paoer industry turns more and more ,„ hardwoods, the wholtrce pulpm .,„ en could be advantageously used for fibre conservation * P han a PUlPÍng he S,0ne 1 w d widely rdused. H,However,l refiner' f' mechanical-S•"< pulpine»" P• has*« recentlv» still the »„in,.,, mos, considerable importance because i, produces be'Jr slreng h p c plLf h " stone-ground wood pulp. Another specacular development in ^ie hañica" pulping ,s thermomeehanical pulping, which gives a pulp with e^n bene strength properties than refiner mechanical pulp. Single-stage oxygeUlkal cooked thermomeehanical pulp is expected to take „ve', confide ab e pof* of production o writing and printing paper in the coming dc"càdè Thermomeehanical pulping ,s already used for the production of newsp n,i„ Europe and the United States. "".»sprint in There has been considerable development in the bleaching of chemical and mechanical pu|ps Multi-stage bleaching of chemical pulps w"h chlorination-extraction-hypochlorite-extraction-hypiKhlorite (CEHEHI is s II used ,n many mills. The hypochlorite stages are mostly being replied by chlorine dioxide stages. As a result, whereas i, was no, possible earlier .„bleach kr ft pulps by the conventional CEHEH sequence ,„ more ,han 85» brightness n d,OXlde PU|PS Can m>W be bk d r'cEDED s;a ?" ^ «° «'-r «I» brig n s by a CEDED sequence (chlonnation-extraction-dioxide-extraction-dioxide) The use of chlorine dioxide bleaching calls for generation of ,he ehem calm IÏ, since ,, ,s a hazardous compound to transport. Although the initial^ op am and equipment for chlorine dioxide production is high, in the longrun , m, "e 0 f he Chl0rine id cansXTa tor a 1skilledLT'T and experienced" ° ' , crew. ** 4enera,ion pL, taw•£ hnah^nrOXÍde. bleauhingJS P•^ in some mi,,s whi<* manufacture high brightness pulps where brightness stability is very important Oxygen bleach n, has become a big issue in connection with environmental j£Z^ ^ so of the most important technical achievements in recent years. The method is not yet fully developed, especially from the economic point of view. Nevertheless, it is considered as established in bleaching of sulphate pulp, and further experience will make it fully accepted by the early 1980s for fully bleached sulphate pulp and presumably also for semi-bleached kraft pulps. In this case, one stage may be sufficient. For the bleaching of mechanical pulps, the application of peroxide and hydrosulphite is quite common. In the chemical-recovery section, considerable progress has been made. For example, several processes have been developed for treating black liquor with compressed air under high pressure at temperatures from 200°C to 300°C. Another process evaporates the black liquor to 30 per cent solids, heating to 330°C and then raising the pressure to 400 atmospheres. Stock preparation systems have been revolutionized by better understanding of the bonding characteristics of the fibre. Pressurized refining and the use of proper additives at correct points ensure better formation of sheet and retention of fibres, fines, fillers and pigments. Except for special-quality papers, beaters are almost compeletely replaced by conical and disc refiners. The designs of these refiners are being increasingly modified so as to reduce the specific power consumption in stock preparation. There has also been spectacular development on the wet end of the paper machine over the past 20 years. Numerous developments in the design of head-box, slice, foil, table rolls and machine clothing have resulted in increasing the machine speed. High-consistency forming has reduced the water-handling in recycling. With the advent of high-speed twin-wire formers, conventional Fourdriniers will find it difficult to retain their position in large-capacity mills in developed countries. The Fourdrinier is still the most common and widely used machine for the manufacture of paper. Phosphor bronze wire is being substituted by synthetic wires, and this has increased machine running availability by reducing the frequency of wire changing. Installation of fabric presses, combination fabrics, the uni-press, Venta-nip presses and the double-felted press have resulted in substantial improvement in water removal and felt life. Multi-nip presses have been developed and are being successfully used. In the drying of paper, steam drying is still the practice. There has been a good deal of work on the condensate-removal system. With the introduction of the closed-hood system in the drying of paper, a considerable steam economy has been achieved. The Madeleine blowing system is gradually replacing the conventional felt-drying system. Technology has been developed for infra-red drying. To what extent this could be commercially employed will be seen in the coming decade. TECHNO-SOCIO-ECONOMIC BASE IN DEVELOPING COUNTRIES In most developing countries, agriculture is the main source of employment. Agricultural residues such as rice straw, wheat straw, kenaf, (il) bagasse, jute cuttings and similar other seasonal materials can therefore be used u ,e^uw,««Ctr> °f PU|P- ,n ,ndÌa' aS many aS 5{) sma" P;,Pcr mill> Producing about 200,000 t have been established, using mainly such agricultural residues One technical option is for a 25-l/d mill using agricultural residue costing Rs 48 lakhs yearly. If the mill takes the agricultural residues from farms within a -5-km radius, the money that would flow to the farmers would come to $S8S per family per year, assuming an average family holding of 4 hectares. On the other hand, ma country such as India, which has a large cattle population, it may not be possible to use all agricultural residues for the manufacture of pulp If bamboo or hardwoods are used as raw material, for every one person employed in a factory, the employment of five persons is created ,n the forest to cut and fell bamboo. As most of this would be in rural areas, a large amount of money w.l flow to the rural people. For a 100 t/d integrated mill, as much as $ 176 m,lhon w.ll flow to rural workers, creating employment for nearly 10.000 people on a full-t.me basis or 20,000 people for six months. By creating d.rect employment in forest areas, the pulp and paper industry has an effect over a much bigger community covering an area where the employment potential is least and where people are reluctant to leave their normal habitat Developing countries with the resources for the production of pulp will earn more by manufacturing pulp and paper instead of sending the raw material outside the country. However, as has been seen in the north-eastern region of India, it «s too costly to take out bamboo for use in mills situated far away A mill has been set up near the raw material sources, and there has been a spurt in the cutting and telling of bamboo, from both the private and government-leased forests. The villagers, who grew bamboo for their own use for making of houses and furniture, are now getting a better price and cash by selling it to a pulp mill It has thus become a cash crop. A pulp industry, apart from the main raw materials such as bamboo or agricultural residues, also uses minerals such as coal, limestone and talc If these materials are available near the factory site, another economic activity is created that provides money for the rural people. CASE STUDY IN PULP AND PAPER PRODUCTION An integrated pulp and paper mill designed to produce paper (90 t/d) and pu p sheet (30 t/d) from bamboo was set up in an Indian rural area about -20 km from the nearest metropolitan city. The population in the area before setting up the mill ( 1971 ) was 3,000 in an area of 10 km*. The population of the if^Lm2 State WaS 2'225'000 and 14,626,000 in areas of 10,360 and /8 520 km*, respectively. About 8 percent of the people of the state live in urban areas The percentage of literacy of the immediate locality was about 8 percent and that of the district and state 22 and 28 percent, respectively Apart from some household cottage units and sawmills, there was no other industrial activity; the population depended entirely on agriculture. The average household consists of eight members, of which three are wage earners. About 80 per cent of the total income of the family is spent on cereals, 10 per cent for (il other foodstuffs, 8 per cent for clothing and 2 per cent for entertainment. Although per capita calorie consumption is around the minimum requirement, the basic needs of the people are covered. Most of the population are not exposed to an urban atmosphere, and the general level of ambition to improve their material well-being was on the low side. The area abounds in forest products, the main items being low-grade timber and bamboo; some afforestation has begun. Other resources of the area include jute, paddy and other grains. By the side of the mill flows a river, which is navigable throughout the year and has a strong current. The area is linked by a broad-gauge railway line, approximately 3 km away from the mill site and also by feeder road to a national highway. Electricity has not yet reached the villages. The construction of the project, costing Rs 220 million, was completed in three years; the mill went into commercial production in 1976. After two years the mill has reached about 80 per cent of the installed capacity. It employs about 1,400 people in unskilled, skilled, supervisory and managerial functions. About 90 per cent of the people are from within the state and 50 per cent are from the immediate locality. The supervisory and managerial people are mostly from other areas because of a lack of technically qualified personnel locally. The first step in the paper-making process, as practised in this mill, is the chipping of bamboo; conventional chippers are used. The chips are charged in a digester along with necessary chemicals in the form of recovered white liquor. Stationary, vertical, indirect, cooking-type batch digesters are used. After a predetermined period of cooking under controlled conditions of temperature and pressure, the contents of the digesters are blown to a blow tank. The pulp stock, containing the spent cooking chemicals, is next screened on an open vibratory screen to remove the uncooked and partially cooked chips. It is then washed in a three-stage countercurrent displacement washer. Hot water is used in the last stage for washing. The pulp from the last vat of the washer is next screened in a series of centrifugal screens, where the shives are removed. The liquor collected from the first-stage brown-stock washers, known as weak black liquor, is sent to the soda recovery section to recover the spent chemicals. The accepted pulp from the centrifugal screen is then dewatered and stored or directly sent to the bleaching section for production of bleached pulp. The weak black liquor is concentrated in multiple-effect, mixed-feed-type, short tube evaporators. The concentrated black liquor from the evaporators is further concentrated by allowing it to come in contact with hot flue gases from the recovery furnace in a venturi evaporator. The heavy liquor is then mixed with the necessary amount of salt cake (to replenish the loss of chemicals during the recovery cycle) and fired in the recovery furnace. The heat value of hot flue gases produced is utilized to generate high-pressure steam. The smelt left at the hearth of the furnace is dissolved with weak liquor obtained from the subsequent causticizing section, and the resulting liquor, known as green liquor, is reacted with lime in causticizers. The slurry, containing white liquor and mud, is then decanted in a white-liquor clarifier, and the clear liquor from the overflow launder of the clarifier, known as white liquor, is sent back to the digester house. The unbleached pulp is sent to the bleaching section. Multi-stage bleaching-chlorination, caustic extraction, hypochlorite stage I, hypochlorite 62 stage Il-produces bleached pulp for screening in a multi-stage centricleaning system to remove dirt, shives etc. It is then cleaned and sent to the stock-preparation section of the paper machine. Conical and disc refiners are used to refine the pulp. Alum, rosin, talcum powder, dyes and other materials are added to the refined pulp and stock. Finally before going to the head-box of the paper machine, it is screened in a three-stage centricleaning system. The accepted stock from the first stage is then diluted with white water and via pressure screen and manifold, enters the head-box of the paper machine. The paper machine installed in this mill is of a Fourdrinier type with a closed head-box and a suction pick-up. The wet sheet is dewatered in a series of plain and fabric presses and dried in conventional steam-drying cylinders with a closed-hood system. The dried sheet is then rewound, cut to size, and marketed. The product of the mill is well appreciated by the market and is selling at $540/1,000 t. The quality-control system adopted by the mill is quite simple. The quality of pulp is controlled, using a Kappa number to indicate whether it will be easily bleachable or not. The test takes about an hour. The quality of the cooking liquor is measured for active alkali, sulphidity and causticity and takes about 10 minutes. The quality of bleached pulp is measured as brightness in a 15-minutes brightness tester. The quality of boiler water is also controlled. Except for the brightness tester, these tests do not call for expensive equipment. A control laboratory with laboratory ware and necessary chemicals is all that is necessary. There is a control laboratory for testing paper installed in the paper machine building itself. It determines basis weight and certain strength properties. For common varieties of paper an elaborate testing facility is not required. A tensile, Mullen and caliper tester are necessary to control the quality; most of the equipment is available locally. The cost of production and profitability at 100 per cent capacity utilization is indicated by the following figures based on 1 t of writing and printing paper: Rupees Dollars Variable cost 2 200 259 Fixed cost 1 000 118 Total ex-factory cost 3 2000 376 Less incentives in excise duty 200 24 Net ex-factory cost 3 000 353 Interest and depreciation 1 100 129 Selling cost 350 41 Cost of sales 4 450 523 Selling price 4 600 541 Profit 150 18 With the granting of incentives, the economics would be even better. The socio-economic benefits that have resulted from such a labour-intensive industry in a rural area where there is unemployment and the living standard is low would justify the setting up of such units in rural areas of other developing countries. The visible benefits seen in this locality are as follows: (a) The villagers have an added source of income from selling bamboo to ù.-ì the mill. Previously, bamboo was used only for roofing and other domestic purposes. Because of the sale of bamboo, the per capita income of the locality has gone up by about $2.40; (b) Villagers are taking greater care in planting and cultivation of bamboo and are growing more of it; (c) The construction of the project was handled by local contractors who had little or no previous experience. This project has enabled them to acquire more expertise and they are now leaving the locality to take up sim.lar new or allied works in other industries that are emerging in the state; (d) The transportation network in the area has been developed; (e) People are gradually becoming accustomed to industrial ventures; as a result some of them are coming forward with signs of entrepreneursh.p; (f) Indirect employment of about 4,000 people in trading and transportation in the mill area has resulted. The capacity of this unit is higher than that offered in the technological options in this paper, but a similar smaller unit would be feasible ancI profitab e, provided the interest and depreciation component does not exceed $94/t for an integrated mill. CASE STUDY IN DECENTRALIZED PULP AND PAPER PRODUCTION Chip production A scheme of chipping units is under active consideration by the Government of Mizoram. A huge forest of untapped bamboo resources in the north-eastern region is beginning to decay for lack of adequate in rastructural facilities To combat this situation, the first stage of an integrated pulp and paper mill is suggested. It would generate employment in the forest, using available skills develop the bamboo areas with proper silvicultural operations and provide accessible roads to make the bamboo available at the nearest point of good communications at an economic rate. The scheme envisages setting up an 80-t/d chipping unit The capital investment, estimated at about $141 million, will generate gainful employmen for 70 people in the factory and 300 in the forest operation. With a If»percent return on investment, the landed cost of chips in a pulp mill situated 800 km from the chipping unit, works out at $29/t. The modestly sized chipping uni using bamboo resources has the maximum employment potential in the rural area The idea is to expand it gradually into pulp and paper. This would both allow study of the actual economy of a paper mill and permit training of local people for various jobs as new sections are added. Taking into consideration the various regional factors, one unit in the states of Arunachal, Mizoram, Meghalaya and Tripura, the north-eastern region is proposed. M Pulp production A pulp mill was set up in a rural area of Gujarat to produce 135 t/d of bleached dried pulp from bamboo or wood. The area abounds in forest resources, and the mill is located by a large river. The project, costing Rs 170 million ($20 million) and employing 600 people in the factory, went into commercial production in 1967. From the cost analysis it appears that the cost of the pulp is very high. This reflects the high incidence of the interest and depreciation component-a problem that is faced by any mill that has come into production since 1967/68. It has also been found that conventional steam-drying of pulp and the subsequent slushing of the pulp for the production of paper also makes for high cost. (This is the reason why most mills in India have an integrated pulp plant with a paper machine.) To offset this disadvantage, the mill has installed a paper machine recently. If the pulp could also have been dried by some other method, the story probably would have been different and the operation might well have been more profitable. Paper production A 45-t/d speciality paper plant, based on purchased pulp, was set up in an industrially underdeveloped area of the State of Bihar, at a distance of about 230 km from the nearest metropolitan city. The area lacks adequate infrastructural facilities, the general population has a low standard of living and the availability of surplus rural labour was high. The plant was originally planned as an integrated bagasse pulp and paper mill. This idea was later dropped, because bagasse could not be made available from the existing sugar mills in the region. It was therefore decided to set up a paper plant using purchased pulp only. The project, costing Rs 80 million ($9.4 million), went into commercial production in 1976. The power required is taken from the public grid. The mill has provided gainful employment for 800 people in the factory. The economics of the operation (production cost and profitability at 100 per cent capacity utilization) are indicated by the following figures based on 1 t of speciality paper: Rupees Dollars Variable cost 3 200 376 Fixed cost 500 59 Total ex-factory cost 3 700 435 Less excise subsidy 400 48 Net ex-factory cost 3 300 389 Interest and depreciation 900 105 Selling cost 400 48 Cost of sales 4 600 541 Selling price 5 000 590 Profit 400 49 The mill can easily produce at the designed rate. However, owing to some extraneous factors such as interruptions in the power supply, the mill has 65 experienced a tremendous setback in production during the last two years. It is felt that if this industry were set up near a port or in an area having good transportation facilities, the economics would have been better. CASE STUDY IN USING BAGASSE There is one mill in India that produces 35 t/d of paper from bagasse. Wet bagasse, obtained from sugar mills, is first depithed. Both dry and wet depithing methods are used and the yield is around 70 to 75 per cent. Depithed bagasse is then cooked at 160°C for about 15 min in a Pandia continuous digester with 10 to 15 per cent caustic soda. The unbleached pulp at 45 per cent yield is next washed in a two-stage counter-current washer and bleached in a conventional CEH (chlorination-extraction-hypochlorite) sequence. The bleached pulp is then centricleaned and sent via the stock-preparation section to the paper machine. With certain minor modifications to the paper machine, it has been possible to make paper using 100 per cent bagasse pulp. Further development of mini paper technology in India M. K. Garg* and M. M. Hoda** BACKGROUND Large-scale mechanized technology of paper making in India was introduced as early as 1905, but it started growing during the First World War. The industry at present is very well developed but still not able to meet growing demand (table 1 ). TABLE 1. INSTALLED CAPACITY AND PRODUCTION (Hundred thousand tonnes) Year Installed capcuitv I'rodiietion 1965 6.74 5.65 1970 7.64 7.73 1977 12.00 9.00 The total number of units is 75, of which 60 are of medium scale. Only four big industrial houses produce 50 per cent of the total production on an organized scale. The capacity of the large-scale paper-making industry, which was originally 30 tonnes per day (t/d) has grown to the order of 100 t/d and many units are as large as 150-200 t/d. The projection for paper demand as made in the five-year plan (1978-1983) is given as follows: "On the basis of the additional requirements of an accelerated programme of adult education, the demand for paper and paper board is expected to rise to 1.425 million in 1982/83. Capacity and production targets envisaged are 1.65 and 1.24 million tonnes respectively. Marginal imports, therefore, may be necessary. "The demand for newsprint is estimated at 270,000 t in 1982/83. With the commissioning of the newsprint project in Kerala, capacity of the industry would reach 155,000 t. A production target of 120,000 t is envisaged for 1982/83."1 The raw material for the paper industry has to be planned on a more »Director (Projects) Appropriate Technology Development Association (ATDA), Lucknow India. "•Executive Director, (ATDA), Lucknow, India. 1Draft five-year plan 1978-1983, p. 194. f>6 rational, systematic and long-term basis, taking into account the limited forest resources and the long time needed for their regeneration. A policy maximizing the use of potential non-conventional raw materials for the production of paper is being formulated. This has assumed importance in the context of a number of new small plants being set up, based on agricultural residues, and the emerging shortages of conventional raw materials to support a growing paper industry. The possibility of establishing large pulp mills to provide long-fibred pulp to small paper mills to upgrade the quality of their output will need consideration. However, given the country's limited availability of long-fibred timber and the options available for making optimal use of them, the establishment of additional capacity for newsprint may not be justified. In this context, provision of public funds is limited to ongoing programmes and for a new pulp and paper project. At present, despite the shortage, only a very small amount, (15,000 t) of special paper is being imported. The need to scale down the capacity of large-scale paper units was felt some time between 1958 and 1960. Conventional paper-making raw materials were becoming scarce and were available only in distant places out of the reach of modern transport. It was therefore felt that smaller units based partly on recycling of waste and partly on utilizing agricultural waste as a raw material could be a possibility for augmenting production, especially for meeting requirements of school exercise books and cheap writing and printing paper. An All-India Seminar on small-scale paper was held in Dalmianagar, Bihar, in 1961. Two types of units were found feasible: (a) a 2-t/d paper plant based entirely on recycled waste paper, and (b) a 10-20 t/d plant based partly on recycled paper waste and partly on agricultural waste such as paddy and wheat straws. The pulp unit for treating the agricultural waste was costly both in terms of unit capital investment and in operating cost. Though half a dozen units were installed based on this process, by 1968 these units were only marginally successful. A new approach, the hot caustic soda process, for preparing pulp for agricultural waste was worked out partly by industry and partly by the Forest Research Institute, Dehradun.2 The costs are estimated as shown in table 2. TABLE 2. RELATIVE COSTS OF CAUSTIC SODA PROCESSES (Rupees) 10-20 I'd plum 10-20 id plain licm (conventional process) (new processi Estimated investment (per t/a capacity) 5 500-6 000 4 500-5 000 Production cost (per tonne) 3 500 2 700 With the adoption of this process by medium-scale paper units, the units have become viable and have been expanding; three to five units every year are on order and there is the possibility of further growth and extension. 2Paper Production-A New Approach (National Industrial Development Corp, 1978). HANDMADE PAPER lls S Paper ¡nduSIry \I " ' ^'" *P* -ere la|fe„ „.^ < »•»«»n was accoun,s f P 7hc han Paper in lh<- r, , T <"- <>-5 Per ceni ,.f ,K Papers. ,„ «dd!,•^ '^ ""T""' "•• ^Sl'" "T «^teï inVÌ,a,ÌOn C«*ÄÄ,=MU*- e,e«* insula^ J^^^^ PAP1:R , ~, - - Ha* material ArtandAr engineering drawing paper ? Permanent document papers" " ^hitc rag, ,a„or "~ rctf,in A|K «f fancy colours ^ * S* Coloured and white r,p Album papers ,C rd8s- ««ton and jute Fi,,e r and meS;¿ ^i •;. —-, firms, s:i:r ^ ^cutt,ngS p.,,,- - "-"'»pañíesP e ai disti,te PlottingB'ottmg paperpape; (white(wWte andrj l^pink •» "^ "^ «^ Packing boards Main ,„H I ipiain and laminated) O'd rags, paper cuttings c„rxra,ionw*•^ File boards Grey boards Road «D,n.f ÍPl"" cu"inSs Straw boards sw a y u r,en7S,y : n¿ *"' "*»" dge dust '" "« Commission, ,ü75) APPROPRIAI* TK, HNO, o<;V KOR PAPKR MAK1N(; water in a tank fr,„„ Ä i^^r^'T'1'•11'' 'S sus technologically not possible """'"'"" "' «>mmon-usagc p:lpcr ,„ P-pe^J uiïo^^rtT T' "'r PUl"-nWk"'* W- medium-scale paper i„«fcs, £ ' v,i.aMi,v ^ '"""' 'n dCmand ^ 'hc innaied lo a level where even vl , vall''•"y is uncertain and their cost is paper industry ,s ^"Ä Z^Z^IZ" "> "" i"""*•'* S mcans lhal if development effort made over the last ihr,, 7 "" L 'he development and improvement of h, T , " "' hc SUS,alncd- fu"hcr , The Appropriai TX, ^tmeT Assf' ,"' M"•" <"" Lucknow has investigated ,h,s prohlem in dTn ^S°C'a""n .ech„„,„gis,s and experts ,„ ^^Z^Tu^'Z^^ papc mechanized,^s^z^^^z^^uir- the manufaernr,. J i V hls proccss can "'»>* * he• scheel exer ise Lok tex L '¡^f^^^e paper, especially for rural undertaken. This r^^J^^/^»•'« P"/P»- can he Already 2-to 3-t/d cylinder machine h Paper-lifting machine, and triplex boards"w^ ^ ÄrT fT^ '"' makÌ"*d"P'« low-grammage paper from this ty ."^ „ ' jfd" ^ a"emP'S *" n""'e prototype of a Fourdrinier naner liftV m*mne dld n<" prove successful. A has h developed. If i, ca "be "fr ,!T Z *? * ^ <"**»' «" low-grammage paper for ZT I ^ handmadc Pa^r industry. could be mlfactuTed. The im du non'of T• J*"** M¡Í ,c»,h•* W U d rCV IU, niZC the presen, rural handmadT pa£ • d st T • " ' " '° feas.ble and economically viable wonmlti 7, , """^ " "-^nically - ^ -Per competitive,^ %>%££ Z£%j£* "*» r ma,ería, Any meanin8ful paper Lnu;:,t^7at,:,a:e ::,e 'H P•«•"* "f Moreover, long-fibre I** T' ^ S<"Cly "" rec*ded "as"-' Furthermore, in order ,o keep he còl Î' '"g k,w-«••««e Paper. P PU P Plants down, the pulp ^ «iTC Äe^lncr T^"'h""", "^ ' kinds of pulp-making their canadtv »IH ^std. The technology „f both the capacit/of the t^ZZ^Zi T^TT"' " "^ capacity of the agricultural waste pulpÄ«^, w.TV^'' '* Viable cent of the pulp wil, be ^ £~ £¡^ » per 71) requires an investment of more than 100 million rupees (Rs). AIDA has been investigating the possibility of scaling down the size of the plant and has had some support for designing a long-fibred chemical pulping plant with a capacity of 30 to 50 t/d if bleaching is not adopted. ATDA has therefore worked out the following programme for upgrading present handmade paper units: (a) Set up a 30—50-t/d capacity chemical long-fibred plant by development organizations and government institutions and arrange distribution of the pulp to rural handmade paper units. Such a plant can be at the State le ¿1. The pulp will be supplied to the small units; (b) Set up a regional pulping plant from agricultural wastes covering two to three districts to be owned and operated by local development agencies, both governmental and non-governmental. The pulp to be supplied to small units; (c) Set up a 1 -t/d rural paper unit complete with a recycling pulping plant on the pattern of the Khadi Commission but with the 2-t/d prototype paper- lifting unit mentioned above. The paper will be manufactured with a suitable mixture of long-fibre pulp obtained from the State pulping plant, agricultural waste, short-fibre pulp and recycled pulp; (d) The handmade paper units will also benefit by obtaining part of their pulp requirements from these State-level and regional-level pulping plants. It is not the intention completely to convert the handmade paper units to the mechanized lifting process. Handmade paper sections will be a useful adjuct to the mechanized-lifting units. The special-quality paper, which is best manufactured by the hand-lifting process, could continue at a better economic level because of the supply of good-quality, lower-cost pulp. Such a programme will increase small-scale paper production to a meaningful level and will meet the local paper requirements in rural areas, generate employment in them and improve their capital formation and economic condition. 71 Annex I TECHNICAL NOTES ON THE MANUFACTURE OF HANDMADE PAPER AND BOARD Handmade paper manufacture uses the following sequence of processes: Rag sorting, cutting and dusting Cooking (digestion) Beating Lifting and couching Pressing and drying Tub sizing Calendering Sorting and cutting Rag sorting Rags are sorted thoroughly for removal of all impurities, that is, all non-fibrous materials such as bidi and cigarette ends, nails, buttons and wood chips. They are then cut into small pieces of approximately 1 -in. x 1 -in. size and dusted through a dusting frame covered with four- to six-mesh wire. Digesting The cooking or digestion of the rags is carried out with a mixture of 1 per cent caustic soda and kept at boiling point for about five to six hours. They are washed thoroughly for removal liquor and sent to the beater. Beating The beater is filled with the required quantity of water, and the digested rags are added gradually. Bleaching powder (1 percent) is then added. After allowing sufficient time for bleaching, the rags are washed thoroughly by lowering the washing drum. The time required for pulping is about six to eight hours where good hydration is desired. Titanium dioxide or other fillers are then added along with dyes (for coloured paper) or optical bleaching agents (for white paper). Rosin soap and alum are added later. Lifting and couching From the beater, the pulp is sent to storage vats near the lifting vat and mixed with a sufficient quantity of water to dilute it to form a uniform suspension and free it from clumps, knots etc. A certain quantity of diluted pulp is then lifted from vats on a wire screen, and the rtsulting sheets are covered by felt. Pressing and drying When a sufficient number of sheets have been formed, they are put under a press to remove the water. The sheets are then separated and, to avoid shrinkage, placed under absorbent boards and pressed again. The sheets are then hung to dry in bunches of three to six, according to thickness. Tub sizing For strong, durable paper, tub sizing or surface sizing is carried out. The sized papers are again dried and cleaned with a brush or cotton wadding to remove dirt specks. Calendering The sheets are then placed alternately under metal plates to form a "post", which is then passed to and fro in between calender rolls to obtain the desired smoothness. Sorting and cutting After calendering, the sheets are carefully sorted and cut to size. The cut sheets are then packed in rolls and dispatched. 7? Annex ¡I TENTATIVE SCHEME FOR HANDMADE PAPER UNITS The unit is expected to produce bond paper, drawing paper, quality cards for invitations, greetings and other quality grades. Other varieties such as file boards and grey boards can also be manufactured. The financial requirements and working of the scheme are based on a unit for producing 240 kg/d of speciality paper or 72 t/a. The total cost of installation is Rs 3 14,000. Financial requirements (a) Building Land about 0.75 to I acre Pucca (brick and mortar) building, 3,200 ft2 Kachcha (mud plaster) building, 2,000 ft2 Water and power facilities (including construction of water storage tank) Cost: Rs 137,000 (b) Machinery Vomiting type digester, 5 ft x 4 ft Rag chopper, 10-in. blade with 3-hp motor Beater, 24-in.x 30-in. roll size (x 2) Electric motor for beaters of 20 hp, 960 rpm, slip-ring with oil-immersed starter (X2) Lifting semi-automatic vats (x 6) Hydraulic press, 40-in. x 50-in. plate size, double ram with 5 hp motor Screw press (36-in. x 42-in. or 35-in. x 45-in. plate size for processing of sized paper etc.) Calender machine for paper glazing (12-in. x 36-in. roll size, complete with accessories) Electric motor for calender machine (10 hp, 960 rpm, with starter) Paper-cutting machine (42-in. x 48-in. blade size) Small beater of 2 kg capacity with V2 hp motor for experiments Washing machine Additional transport costs, taxes, costs of erection etc. Cost: Rs 132,250 (c) Equipment Chain pulley block with tripod, 2-t capacity Platform weighing balance, 500 kg capacity Pulp storage tanks for lifting vats (x 6) Washing cradles for pulp washing Press boards for paper lifting (x 24) Zinc sheets for calender machine, 4 ftx 3 ft (x 40) Woollen felts (x400) Complete sets of carpentry tools, pipe-fitting tools etc. Small (2 kg) pan balance Towel horses for keeping felts (x 6) Sizing trays Grinder Dusting frame Spare parts for moulds etc. Couching tables (x 6) Stools for vats, paper separation Drying arrangement Other miscellaneous articles: buckets, brushes, hardware stores etc. Additional taxes, transport etc. Cost: Rs 29,700 (d) Office equipment Typewriter, cupboards, tables, chairs, racks, clocks etc. Storing arrangements for finished paper, chemicals etc. Cost: Rs 15,000 Total cost Building Rs 137 000 Machinery 132 250 Equipment 29 700 Office equipment 15 000 Rs 313 950 Working of the scheme In order to operate the unit smoothly and economically, it is necessary to work in several shifts. The economics of working the basic unit in two shifts is as follows: Beater operation in three shifts Lifting, pressing, paper separation, digestion (if necessary) in two shifts Other processes in one general shift (a) Raw materials and chemicals New rags, 90 t at Rs 1,700/t Caustic soda flakes, 1 per cent: 900 kg at Rs 3.50/kg Bleaching powder, 1 per cent: 900 kg at Rs 1.50/kg Titanium dioxide, 1 per cent: 900 kg at Rs 8.50/kg Rosin, 1.5 per cent: 1,350 kg at Rs 3.00/kg Soda ash, 400 kg at Rs 1.50/kg Alum (non-ferric), 3 per cent: 2,700 kg at Rs 1.00/kg Glue flakes, 3 per cent: 2,700 kg at Rs 7.50/kg Optical bleaching agent: 50 kg at Rs 50.00/kg Formalin, 720 I (700 kg approximately) at Rs 2.50/kg Diacol M, 15.5 per cent: 450 kg at Rs 5.00/kg Miscellaneous chemicals such as colours (dyes), soap, kerosene and ultramarine Nue Cost: Rs 203,500 (b) Labour Number of persons Remark s Rag sorting 6 female General shift Rag dusting 4 female General shift Rag cutting 22 male In shifts Digester 2 male In shifts Beater men 4 male In shifts Beater assistants 4 male In shifts Vat men 12 male In shifts Couch men 12 male In shifts Press and wet paper separation 8 male In shifts Paper drying 4 female General shift Paper sorting and khurapi 6 female General shift Glue sizing 4 female General shift Calendering 2 male General shift Paper cutting and packing 1 male General shift Labour for miscellaneous work 5 male In shifts Chowkidar (night watchmen); number of working days in a year: 300 4 male In shifts Carpenter/mechanic 1 male In shifts Helper 1 male In shifts Additional costs: holiday salary, provident fund, gratuity and other labour benefits, 30 per cent Cost: Rs 163,020 (c) Other manufacturing expenses Water charges Power charges Fuel (for cooking and drying) Cost: Rs 33,600 (d) Staff and other expenses Manager Supervisors (2) Accountant/storekeeper Clerk/typist Messenger Additional holiday salary, provident fund, gratuity. Employées' Social Insurance scheme etc. at 3 per cent Cost: Rs 31,410 (e) Repairs and replacements Telephone, taxes, insurance etc. Postage and stationery Travelling expenses Repairs and replacements Cost: Rs 10,000 76 (f) Depreciation On puce a building On kachcha building On machinery On equipment On office equipment and furniture Cost: Rs 22,650 (g) Interest at 9 per cent On capital expenses of Rs 314 000 On working capital (roughly equivalent to four months' requirements) Rs 100 000 Rs 414 000 Cost: Rs 37,260 Summary of expenses Raw materials and chemicals Rs 203 500 Labour 163 020 Other manufacturing expenses 33 600 Staff and other expenses 31 410 Repair and replacements 10 000 Depreciation 22 650 Interest at 9 per cent 37 260 Rs501 440 This permits production of good-quality finished bond and drawing superior card at a rate of 240 kg/d, i.e. 72 t/a. Actual cost of production will be Rs 6.97/kg. Taking into consideration discounts and profit margin, the selling price will be Rs 8.25/kg. Sales revenue Rs 594 000 Less 10 per cent discount to be given to customers 59 400 Net revenue 534 600 Less expenses shown above 501 440 Net profit Rs 33 160 Notes Costs are those prevailing in urban areas. However, actual expenditure may come down at certain places owing to local circumstances. Also, some equipment items can be manufactured locally and thus further bring down cost. The same holds for raw materials, chemicals etc. if special efforts are made to obtain them at low rates. The sales price indicated above is an average. It may be a little higher for thinner varieties and lower for thicker grades. The scheme is based on the price prevailing in 1972. Since then, prices have fluctuated, but the basis will remain the same. With the increase in investment, production would have to be increased, for example, by installing on& ore more beaters and running the vats in three shifts. 77 In the same unit, with the help of the same machinery and equipment, the following varieties can also be manufactured: Filter paper Electric insulation paper Album paper File boards Straw boards Grey boards Blotting paper The processes and raw materials, chemicals etc. vary depending upon the type of raw material and quality of paper to be manufactured. The search for an appropriate technology for the paper and board industry of the United Kingdom D. Attwood* In more recent times, countries with forest resources have been keen to sell their products with the highest possible added value. Countries that once were prepared to sell pulp-wood now wish to sell pulp, and countries selling pulp wish to sell paper. This policy has been a contributory factor in the rise of global prices for pulp. . The United Kingdom has thus had to seek other sources of raw material and has turned to waste paper which it now sees as a major source of indigenous raw material. This is an example of the United Kingdom's use of appropriate technology. Other indigenous raw materials, notably straw, have been investigated in depth. The lesson here for a developing country seeking to build up its paper industry is to concentrate on the raw material and to give first priority to forests or other resources of fibrous material. Waste paper M a raw Material Paper making originally relied on rag merchants to supply its fibrous materials. After a period in which wood-pulp provided the bulk of the raw material, economic necessity is forcing United Kingdom manufacturers to rely much more heavily on waste paper and dealers in it are now an extremely important link in the supply chain. Waste paper was always a prime raw material for cardboard and carton board. It is now used also for the manufacture of substitute flutings and liners for case-making. Its use is also growing in the United Kingdom for manufactured newsprint. ,-••**. Another grade where waste paper is becoming more popular is tissue. The waste-paper processing system for soft-tissue manufacture is relatively simple. It •Director. The Research Association for the Paper and Board. Printing and Packing InduMriev Leatherhead. Surrey, United Kingdom of Great Britain and Northern Ireland. 7« 79 consists of a waste-paper pulper fitted with a junk trap, but no ragger, followed by high-density cleaning and centrifugal separation. Further high-consistency screening is carried out, and the rejects from the equipment are treated on vibrating screens. However, there are two weaknesses to the use of waste just described. First, the quality of the waste must be maintained so that the simple processing system remains adequate. Secondly, the quality of the product dictates that the waste be both bright enough and soft enough. Thus very little ink should be present, and the ash content should be very low. An alternative system under active consideration in the United Kingdom is to use a more extensive processing system. The waste could then be relatively unsorted, with any degree of printing and high ash content. Other sources of raw material About 4 million tonnes of straw are wasted in the United Kingdom each year. It would thus seem an ideal source of raw material, even allowing for its slowness as a pulp and its low yield in conventional cooking. Without even considering the technical problems, however, there are very real impediments to the introduction of a straw-pulp mill in the United Kingdom, quite apart from the logistical problems of collecting straw during a six-week harvesting period to provide a 52-week supply. Some further impediments to the preparation of bleached straw pulp are: (a) Straw is less dense than wood and does not easily pack in the digester; (b; Straw nodes usually resist attack by the cooking liquor and can lead to rather high losses at the screening stage; (c) Straw is very wet and does not part with water very easily. It is therefore more difficult than wood to wash and requires rather more water than wood, which in turn leads to weaker black liquor going into the evaporation stage; (d) The silica, which is always found associated with straw either in the plant skeleton or as dust adhering to the stem, is dissolved by the cooling liquor and then precipitates out in the evaporator. This produces a very hard scale which in turn reduces the efficiency of the operation; (e) Silica glass can also form in the recovery furnace, usually on the pre-heater tubes or superheater; (f) The calorific value of straw black liquor is lower than that from wood and it is also more viscous. There could be a problem in producing a final liquor that would burn and. at the same time, flow through the furnace inlet nozzles. Nevertheless, straw is successfully pulped in many countries, and there are over 40 distinct processes for treating it. Stime have never been commercially exploited, but others are in use commercially in producing straw pulp in many parts of the world. Research work in the United Kingdom has yet to he completed, but the ammonia-oxygen process seems promising, as does "universal pulping". HO In the latter system, the pulping process has been chosen to furnish a black liquor that, instead of being recovered in the normal manner, can be modified for use as a partial starch replacement and as sizing in low-grade papers. Pulping technology and requirements and potentialities of developing countries G G ave I in* INTRODUCTION A given paper product can be manufactured from many different pulp grades, used alone or in blends, with or without addition of fillers and chemicals Many pulp grades can be made from widely different species of trees or plants The wide choice of technology thus offered is materially narrowed down by the limitations imposed by local conditions. When a choice is made, it is necessary to know about the processes available in order to be able to assess the possible applicability of each to the end-product considered, the raw materials available the size of production desirable and the geographic and economic conditions at the site under consideration. When prices are cited, they refer to the Swedish market in 1978 and are given in United States dollars ($). They are only meant to give approximate cost relations. PULPING PROCESSES Mechanical pulp Stone-ground wood (G WP) The process of grinding wood into mechanical pulp was invented in 1840, when the only alternatives were pulps from cotton and straw. Chemical pulps did not arrive until 1870. However, it was only in the 1960s that fibre morphological mechanisms were sufficiently understood to apply modern technology to the manufacture of mechanical* pulp. Shortly afterwards, interest was drawn to chip-refining processes This change was conditioned more by scientific advances than by the obsolescence of the GWP process. If mechanical pulp is to be produced, the GWP process is still one of the alternatives that must be considered. Process requirement-*}*? can be produced from poplar, aspen, some species of eucalyptus, gum and most softwoods. Dense hardwoods are not suit- able, giving dark and very weak pulps. Pine with a high pitch content may give too much operating trouble although some improvement can be achieved Tonsuhanl to the Swedish International Development Authority (SIDA), on hehalf of which ihn paper wat prepared. HI by alkaline grinding. The wood to be ground must be available as logs, preferably green, from the forest, straight and carefully debarked. Sawmill wastes are not usable. A 6,000-V electrieal supply and clean water to an amount of 10-1.S cubic metres per tonne (m3/t) are the other requirements. The process is simple. I he only work requiring specialized training is weekly sharpening of the grinding stone. Quantity-related cost items-To produce one tonne of C1WP (900 kg of bone- dry fibre), 233 m:i of solid debarked wood is needed. The wood yield is difficult to determine accurately, but will be in the range of 95 to 97 per cent. Depending on the pulp grade made (from coarse paperboard pulp to pulp for addition to fine printing paper) the energy requirement will be 800 to 1,500 kWh/t These two cost items are the main ones and are almost independent of plant size. The following data apply to a non-integrated GWP mill producing 100 tonnes per day (t/d) of news-grade pulp: (Jituntitv Cr/W f$ n Wood 233 m3 «3 Electricity for grinding 001) kWh/t 50 Electricity for screening, drying 500 kWh/t 50 Fuel oil for drying SO litres/t 7 Wrapping material, stones 6 Total of quantity-related items 146 Labour costs—Labour costs are dependent on the size of the plant, but even in a small plant they are comparatively low. Capital costs—An estimate made in 1977 by the Swedish Forest Research Institute (SFRÍ) gave an investment cost of $5 million for a 100 t/d GWP mill, $9 million for a 330 t/d mill, and $21 million for a 900 t/d mill. These sums do not cover the wood yard or drying and baling activities. Including these departments, the above figures would be respectively $9 million, $150 mil- lion and $59 million. Such cost figures should be treated with great care, since they are based on data pertinent only to one particular case and time. It is interesting to note, however, that the investment cost per unit capacity drops from $90,000 at 100 t/d to $65,000 at 900 t/d. It is clearly desirable to design more economic small mills. The GWP mill is well suited for such efforts by the comparatively small size of its basic production unit, the grinder. Restrictions on location-A small GWP mill should be located close to the source of wood and offer cheap transportation of the pulp to the consumer in order to keep the cost of dewatering, drying and baling to a minimum. Refiner mechanical pulp (RMP) Refiner mechanical pulp is produced by refining wood chips in disc refiners without use of chemicals or steam. The same raw materials are used as for GWP, but the wood can arrive at the mill either as logs, which are then chipped, or as chips, sawdust and other residues from sawmills and wood-processing industries. Pulp quality-RMP is 50 to 100 per cent stronger than GWP from the same wood of equal drainage characteristics, but this high strength has to be paid for by the use of about 50 per cent more electrical energy ( 1,200 to 2,200 kWh t) 1.0 : « 125 22 I.I 20 1.25 IH.4 1.6 MH Km oi'Y IVI snillllON MM i MAIv SI Production cost.s-li was mainly the prospect of a cheap raw material tor newsprint that prompted and justified the expenses of developing the RMP process. Thus, for a long time, all efforts were concentrated on making an acceptable pulp from sawmill waste, while little attention was given to the economy of the process. A general feeling developed that the capital cost of the plant was equal for GWP and RMP, and that the higher energy cost of RMP was more than compensated for by a lower wood cost. Thermomechanical pulp (TMP) TMP is a further development of RMP, characterized by the addition of a steam treatment of the chips prior to refining. This treatment softens the chips and greatly reduces fibre damage in the initial phase of the fibre separation. As a consequence, TMP will normally have a lower shive content and a higher long fibre fraction than RMP. Dusting and linting will be under better control. Both tensile strength and tear resistance will be higher than for RMP of equal drainage characteristics. To quote firm percentages for these differences would, however, invite many protests from manufacturers of both RMP and TMP. There are many varieties of the RMP and TMP processes adapted to different end-products and to different refiner designs. It is difficult today to draw a strict line between the two processes. Currently, in a typical TMP plant the chips are pre-steamed in a pressurized vessel at 120° to 130° C for two to three minutes and then immediately refined at the same pressure. They are then refined in a seconu stage at atmospheric pressure. Alternatives are pressurized single-stage refining, pressurized refining in two stages, atmospheric single-stage refining and atmospheric steaming followed by pressurized refining. Quantity-related cost items-The wood vield in TMP manufacture may be 1 to 2 per cent lower than for GWP. Most published records indicate a yield in the range 92 to 94 per cent. Peroxide bleaching will reduce the yield further by 1 to 2 per cent. The energy requirement is 400-500 kWh/t higher than for GWP: about 1,400 kWh/t for a board-grade pulp and 1,900 kWh/t for a news-grade pulp, including screening and cleaning. This difference between the two processes is not significantly affected by steaming the chips. The following data apply to a TMP mill producing 100 t/d of news-grade pulp: Quantity Cost ($:t) ;, Wood 2.40 m /t 85 Electricity 2 000 kWh/t 67 Fuel oil for drying 80 litres/t 7 Wrapping material, refiner plates 7 Sum of quantity-related items 166 This is $20 per ton more than for GWP manufacture. Thus where it is technically possible to grind the wood to be used, it is prudent to take a close look at the economy of the two alternative processes before an investment decision is taken. Labour ram-There is no difference in labour demand between a TMP plant ,S4 a,5U e same in both cases includingmrHHn« office^ff;„0 „staff:•„«. " ine Capacity (1/ d) Labour cost ($//) 50 40 100 20 350 9 900 7 Where labour is cheap, a small plant will be more competitive Capital costs-A 1977 renort nf crpi „ ,, , „ SFR gaVe ,he followln es,i vestment costs ($ mi||io„,: ^ ' 8 •'«i in- Capacity (ttdi Woodyard (JwT 7UZ »Wg and 1J^___ 50 , , '^'W pr0per,ies of pulp are to bVretled fc H T" T* mechanical H 5 Labour costs-Labour costs for a CMP mill are the same as for a TMP mill (see above). Capital costt-Physically, the CMP plant will differ from the TMP plant only by the addition of a 10-m3 tank for the chemical solution, an impregnator, and a somewhat larger pre-heater. For a production of about 150 t/d, the extra investment should not exceed $3()0,()0(). This means capital costs about $2/t higher than for a TMP mill. It would appear that the cost of chemicals is the only important factor weighing against CMP. The customer must be willing to pay at least $ 10/t more for CMP than for TMP. Chemithermomechanical pulp (CTMP) CTMP is a TMP made from chemically pre-treated chips. Lately, a number of articles have been published that report remarkable quality superiorities of CTMP compared to TMP. In particular, higher cleanliness and higher strength are claimed. The energy consumption is not significantly affected by the use of chemicals. CTMP technology is under rapid development, and it is not yet known which variety of the process will prevail. The disadvantages of this situation must not be exaggerated. Generally, the procedures adopted are so simple that they can easily be adjusted to fit coming process developments. The investment decisions can only be marginally affected by these. What cannot always be foreseen with certainty is how much is to be gained by going from TMP to CTMP, and how the CTMP option will affect the usefulness of a certain wood species. If the problem is to improve the quality of a TMP pulp, there are three possibilities: (a) To apply just the required amount of chemicals to the chips before refining; (b) To threat only part of the chips flow with so much chemicals that optimum pulp quality is obtained, and to mix this higher grade pulp with the standard TMP; (c) To treat only the screen rejects with chemicals before the reject refiner. If the problem is to pulp a low-quality wood, only the first of the three alternatives will be of interest, and more attention may then have to be given to the impregnation process than in pulping spruce or pine. Labour costs-The CTMP process differs from the CMP process only by the fact that in the former case the pre-heater is pressurized, and in the latter case it is atmospheric. This will have no effect at all on labour cost. Capital costs-The impregnator and pre-heater will have to be built as pres- sure vessels, while in the CMP process they are atmospheric. The extra cost of pressurization will add $l-$2/t U the capital costs of the CMP process. However, chemical cost will be the same as for CMP. Comments-The choice between the CMP and CTMP processes will depend on pulp quality considerations and on the wood species used. There may also be a desire to produce TMP as well as CMP or CTMP in the same plant. On the other ,V6 hand, it is possible that, with some wood species, the CMP process will give a better pulp than the CTMP process. It is advisable to start by steaming the chips at atmospheric pressure, using excess steam from the process. Thereby, air is expelled and the chips obtain uniform temperature and moisture. No chemicals should be added at this stage. The chips should then be washed in 70° C hot-process white water for removal of sand and loose bark and for a more uniform chip moisture. After draining off water from the washed chips one can proceed to impregnation with chemicals A low temperature at this stage is preferable, but it is not feasible to go much below the white-water temperature of 70° C. The chemicals penetrating into the wood will swell the fibre wall and react with the ¡ignin, making the latter softer and more hydrophilic. A later treatment in the standard TMP pre-heater causes the modified lignin molecules to polymerize so that they are less easily solubilized. Chemicals that have not reacted with the wood will be partly recirculated with the white water back to the CTMP mill. No chemical recovery process is needed. Process alternatives Bleaching mechanical pulps-All mechanical pulps can be bleached to 7 S to 80 per cent brightness with sodium peroxide. If a brightness level of 70 per cent is adequate, bleaching can be done simply by adding 2 per cent peroxide to the dilution water going to the first-stage refiner while controlling the pH at close to 8. If a brightness above 75 per cent is required, it will be necessary to add a peroxide bleach tower for a two-hour treatment of the pre-bleached pulp after screening and dewatering to 15 per cent consistency. It is not usual to wash the pulp after bleaching. Excess peroxide will do no harm to the process or the machinery. While peroxide bleaching of mechanical pulp has been practised for a long time, only recently has the process been developed to a stage where appreciable improvement of strength and cleanliness is obtained. Peroxide is, in any case, only of interest if a high brightness is needed as well as high strength. Alkaline sulphite treatment-U strength and cleanliness are the prime considerations, an alkaline sulphite treatment should be considered. With 3 per cent sulphite plus 3 per cent alkali, the cost of the chemicals will be around $ 12/t. The cleanliness of the pulp is dramatically improved, presumably because the shives become softer and more easily disintegrate into fibres in the reject refiner. Alkaline-sulphite plus peroxide-U the goal is to combine maximum strength with high brightness, it is technically possible to add a peroxide tower after an alkaline sulphite CTMP plant. Since a reaction between sulphite and peroxide must be avoided, the stock should be pressed to high dryness before going to the bleach tower. This involves capital expenses which may make the alternative less attractive. Although the technology required is fully developed, no such system s in operation. CTMP can be made both from softwood and hardwood, but the chemical reactions in the wood are different. Hardwood calls for more alkali and less sulphite than softwood. H7 Ozone treatment-Aìthough only one installation is presently in operation, the ozonation process must certainly be considered an interesting method to influence the characteristics of fibre surfaces. The process, however, is not enough advanced for a detailed presentation to be justified, and the comparative complications of the process do not make it very suitable at this stage for most developing countries. Limitations of mechanical pulps However advanced the process, all mechanical pulps are subject to three limitations: (if) A stable brightness above 80 per cent is not obtainable, and any brightness improvement achieved is rapidly lost by exposure of the paper to sunlight; (b) A paper strength adequate for packaging paper is not obtainable; (c) Paper containing mechanical pulp will become brittle and yellow after a number of years and is therefore not suitable for books or important documents. Main uses of mechanical pulps (MP) MP is used in newsprint and, to some extent, in most other printing papers. It is found in many tissue products and sometimes in the centre.ply of paperboard. The important market is newsprint. Newspapers are printed with an oil-based ink which is "dried" by absorption of the oil into the paper, and only MP can give the newsprint the rapid oil absorption required. Water pollution in MP manufacture The water pollution caused by an MP mill need not be very alarming. If the use of fresh water is restricted to 10 m3/t, which is entirely feasible, the effluent can be aerated in lagoons at reasonable cost. The effluent does not hold any poisonous matter except for wood resinous acids, which are rapidly broken down by aeration. Semichemical pulps The two common grades of semichemical pulp are cold soda pulp and neutral sulphite semichemical pulp (NSSC). The cold soda process As the name implies, the raw material is treated with alkali at room temperature before refining. Earlier, refining was done in purnp-through refiners at 4 to 5 per cent consistency, giving pulps of poor cleanliness and strength. The process, which is only applicable to hardwood, was first introduced in 1955, and for some years became quite popular. Compared with other chemical and semichemical pulping processes, the cold soda process has a very uncomplicated system for liquor recovery. The only difficulty is to obtain economy from it and still avo^d water pollution. However, industry has somewhat lost interest in the cold soda process because higher-quality pulp can be obtained by other processes using sulphur. Still, present experimentation in the area of sulphur-free pulping may lead to improved varieties of the cold soda process. The modification could be as simple as the addition of i small amount of catalyst to the alkali. Therefore, developing countries, understandably wary of untried technology, may find it wise to follow developments in this field closely. Neutral sulphite semichemical pulp (NSSC) NSSC can be produced from most species of hardwood. The chips are steamed at atmospheric pressure, and impregnated with a solution of sodium sulphite and sodium carbonate at a pH of 8 to 9. The wet chips are digested by steaming (vapour phase) in a pressure vessel at 160°-180° C for 15 to 60 minutes. By this process about one half the lignin and one third of the hemicellulose are dissolved. The cellulose, however, is not attacked under normal cooking conditions. The middle lamella, which holds the fibres together, has (especially in hardwoods) high contents of lignin and hemicellulose and is therefore primarily attacked by the cooking process. As a result, a later refining of the digested chips will give comparatively undamaged, strong fibres. Softwood is less suitable for this process because of a lower lignin content of the middle lamella. The wood yield is in the range 75 to 85 per cent, which means that some kind of liquor recovery is necessary in order to limit the pollution of the recipient. Below 75 per cent yield, the pulp quality will deteriorate, and other pulping processes become more attractive. A normal level of consumption of chemicals is 8 to 10 per cent sodium sulphite and 2 to 5 per cent sodium carbonate. Labour costs-A cold soda plant or a NSSC plant will always be a department of a paper mill, and its labour cost can be seen as a certain part of the total for the mill, or it could be referred only to the extra personnel needed for pulping. For a 150 t/d plant, under Swedish conditions, this extra personnel would be: Wood-room operators (two shifts) 4 Pulping operators 10 Extra maintenance (day-shift) 3 Process and quality control 2 Superintendent _l_ Total employed 25 The labour cost would be about $8/t. Capital costs- All modern NSSC mills have been built as integrated parts of kraft pulp and paper mill combines, so the capital cost of the NSSC plant is, there- fore, practically impossible to extract. Essentially, the production cost of NSSC depends on the cost of the wood used. Where there is a local surplus of hardwood, conditions will be far more advantageous than where hardwood can also go to a kraft mill. Uses of NSSC-The important quality characteristic of NSSC is stiffness combined with a certain tensile strength and absorptivity. The pulp is almost exclusively used for fluting, and blended with kraft waste fiber for economy and increased wet strength. It is also possible to mix a little NSSC into the kraft furnish for liner to obtain increased stiffness. In both applications, NSSC will give superior paper characteristics compared to CTMP or kraft waste paper. Recovery of chemicals-Thc NSSC process would lend itself ideally to manufacture of pulp from mixed hardwoods in small plants located in forests. m Instead NSSC plants are generally large and built adjacent to kraft mills The explanation is that the only practical method of recovering the cooking recTver ) * ^ PUmP ^ ^ * ^ ^ Wack ,iqU°r reC°VCry system Sulphate pulp (kraft process) Sulphate pulp is produced by digesting chips in a liquor of mainly alkali and sodium sulph.de at 160° to 170° C for 2 to 3 hours. By choosing the appro- priate operating conditions, one can manufacture a wide range of pulp grades from high-yield liner pulp to dissolving pulp. For developing countries, the kraft process has the special attraction that almost any wood can be used - hardwood as well as softwood. It is also possible to process a blend of species without great inconvenience. Unbleached softwood kraft pulp ,s unsurpassed for packaging papers (sack paper, wrapping paper, liner), while bleached hardwood pulp is a soft, opaque, easily refined pulp of high and stable brightness, suitable for printing paper, tissue and paperboard Still, especially in developing countries, there are reasons for avoiding this process where possible because of: (a) The scale factor: Owing to the advanced technology used in kraft pulping which is applicable only to large plants, a small pulp mill is not competitive with a large one. In 1972, it was computed that a bleached kraft mill for 35,000 tonnes per annum (t/a) would cost 2.6 times as much per daily tonne as one for 350,000 t/a. Today, this ratio is probably higher. For a mechanical pulp mill the capital cost is only 25 per cent of that of the kraft mill, and the specific cost increases more slowly as the plant size in reduced; (b) Availability of chemicals: It may sometimes prove difficult to ensure reliable deliveries of the chemicals and raw materials needed in kraft pulping and oleaching; F F ë p Technology: Kraft pulping involves a number of chemical processes all of which must be controlled very strictly. In an isolated small mill it may prove difficult to establish the necessary standard of supervision- W (cl) Fcology: In a developed country, even a small kraft m.ll poses almost insu rmountable ecological difficulties because of the exorbitant cost ot the •ed a¡pollution measures. The difficulties are caused mainly by the use of Xnur in the process, but sulphur is the prerequisite for the favourable quality mix exh bited by kraft pulps. In developed countries small kratt mills are being d^d down oryrebuiltP,nU> large, modern units, and the dcvctopmcn. o new antipollution technology is geared exclusively to the needs of the latter type ot plant The same goes for the pulping technology. Since kraft pulping cannot be entirely avoided in developing countries, it shoukl be realized thaUhe potentials for adapting the kraft process t^ndit.ons and requirements of such countries have not really been explored. When a new smtl plant is ordered, for example, the 150-t/d plant at Ba, Bang ,n Vict Nam, r w 1 not allow anything but standard technology. Conditions should be mo« favourable for special development when the plant is to be bu.lt on a barge, like the 750-t/d plant recently shipped from Japan to Brazil. What is needed is a fresh look at each process step. Perhaps in-line mixing should be used instead of blending tanks, perhaps filters instead ot settlers, peaps presses instead of filters, perhaps ejectors instead of vacuum pumps etc P E'en so, it is not likely that a small kraft mill built today «" a^velopmg country will ever be able to complete economically with a large kratt mill built in a developed country in the early 1970s or even earlier. The conclusion seems to be that when small kraft mills are buUt ,n developing countries, one should, from the start, count on their being uncompetitive on the world market. However, such ventures may still be juTed because of the effect on the industrial structure of the country, reforestation, and the labour or foreign exchange situations. Sulphur-free pulping processes Sulphur-free pulping is becoming less complicated than kraft pulping IBe- cause causticizing and lime burning become unnecessary, and gas collection and Thingca" be eliminated. Anthraquinone ^^^f^T^^ appears to be the most advanced. Pulping with alkali and 0 1 to 1.0 per cent Sra uinone has given pulps with somewhat higher yield;;^ somew lower strengths than kraft. The economy of the process, however, is still not venattractfve. At this stage of its technological development, it would not be a serious alternative for a project in a developing country. Oxygen-alkali pulping For many years now kraft pulp has been bleached with oxygen in a first- bleach stage, which removes about 40 per cent of the lignin from the pulp. Bleaching is hen continued in a conventional bleach plant. Attempts are being made to extend this process to the initial delignification of wood. The process rhovveveÌat an earïy stage of development and enough data are not available to estimate its economic aspects. w CHOICE OF PROCESS FOR A GIVEN END-PRODUCT Newsprint The use of oil-based printing inks necessitates mechanical pulp in newsprint. Chemical pulps do not give the paper a fast enough oil absorption. The paper web is subject to transient stresses on the paper machine, in the winder and on the printing press, which necessitates a certain combination of tensile strength, tear resistance and stretch of the paper. These characteristics are obtained by mixing 10 to 25 per cent chemical pulp with the mechanical pulp. The exact mix required depends on wood species, production processes and paper quality requirements. Raw materials Practically all types of softwood can be used, although spruce is generally preferred to pine owing to its lower pitch content and lower energy requirement. In some developing countries, however, softwood may be so scarce that it should be reserved for the manufacture of packaging papers, for which there is no good alternative to softwood. Hardwood is used for newsprint in several countries. Twenty-five per cent chemical pulp is added to the newsprint furnish. A newsprint mill recently started up in Greece has a TMP plant planned for the use of poplar. The higher strength obtainable with the CTMP process may further increase the usefulness of poplar in newsprint. In Australia, eucalyptus is used as the main constituent of newsprint furnishes. The wood is ground under alkaline conditions, using a specially developed technique that gives the pulp an acceptable wet strength. If a new plant were to be built today, the technique to be applied would definitely be the one of the CTMP process. As far as is known, however, there is still no news- print mill in operation using eucalyptus CTMP. Aspen in used for RMP and TMP in North America magazine paper mills and could certainly be used also for newsprint. Gemlina arborea, an African hardwood, is another possible choice for newsprint. In addition, bagasse can be processed into a pulp which, although not strictly an MP, lends itself to newsprint manufacture. Bagasse newsprint has been made for a long time on a small scale, but recently a 390-t/d newsprint mill has been built in Peru that uses 75 to 90 per cent bagasse fibre prepared according to the Cusi method, that is, the bagasse is given a comparatively weak alkaline cook and is then fractionated. The coarse fraction is refined and the two fractions are then blended. One advantage of this process is that the pulp can be refined without loosing too much drainage. In general, the development of many new pulping processes has made it much easier to find a suitable raw material for newsprint. If newsprint manufacture is contemplated in a new location, it is advisable to make a careful assessement of the suitability of the raw material available considering all the pulping processes applicable. This can usually be done with adequate reliability by pilot-plant pulping at a research laboratory or in the laboratory of a machinery supplier. 92 Optimum furnish mix There are paper mills operating where newsprint is made from imported pulps exclusively. Such mills, however, find it quite difficult to compete with imported newsprint. A better approach is an integrated MP plant and a regular supply of imported kraft pulp. Newsprint manufacture based on 100 per cent local MP could have considerable attraction for a developing country. Although making newsprint from 100 per cent MP calls for some process modifications, they easily incorporated in a new plant. One particular difficulty of newsprint ventures is that newsprint is such a low-priced product that one wants to make it on the widest and fastest paper machines possible. In industrialized countries, a modern newsprint machine may have a capacity of 500 t/d. In developing countries, the answer to this problem could be to use one paper machine for the manufacture of both newsprint and a number of other paper grades. Magazine papers The term "magazine paper" covers a wide range of printing papers holding 60 to 100 per cent MP. This diversity makes magazine paper particularly attractive for manufacture in developing countries. Knowing the technical requirements of the printer (which the printer may not always know himself) and the wood species and fillers available one can, as a rule, find many alter- natives. Procedures in developed countries should not be copied too closely. For example, surface sizing with starch may be more economical compared to the use of high-strength CP than it is in developed countries. Fine papers Paper for books and documents which are to be kept for a long time should be made from 100 per cent CP. Opacity being more important than strength, hardwood CP is used to the highest extent possible, considering the demand for paper machine efficiency. A mix of 70 per cent hardwood and 30 per cent softwood kraft is usual in fine papers. Tissue The annual tissue consumption per capita in industrialized countries averages 30 kg. This figure allows a rough estimate of the latent demand for tissue in some developing countries. The manufacture of tissue should meet no great difficulties anywhere. Although a modern tissue machine is a product of advanced technology, it is comparatively simple to operate and maintain. Liner and fluting Liner and fluiing are the two constituents of corrugated fibreboard. Kraft v.? liner is made from unbleaehed kraft pulp of two grades with slightly different properties: Ihisc pulp I up i>ulp Wood yield (per cent) 54 4S Kappa number 8(M>() 45-55 Freeness SR 18 30 The base pulp should give the liner high strength, high stiffness and high bulk, while the top pulp should give it a cleaner and smoother surface with better printability than the base pulp would give alone. Fifteen to 20 per cent of NSSC can be mixed into the base pulp for economy and increased stiffness. Alternatively, one can mix in about I Oper cent corrugated waste, which also holds NSSC in the fluting. Kraft liner has a basis weight of 125 to 350 g/m2, of which the top ply is usually 30 g/m2, independent of liner basis weight. Kraft liner is a well-standardized "bulk" product, and the capacity of a modern liner machine is generally 200,000 to 350,000 t/a. Obviously, it will not be easy for a developing country to compete with such large units on world markets. Nevertheless, kraft liner mills in the capacity range of 20,000 to 30,000 t/a are being built in developing countries, and in South America, two kraft liner projects in the range of 150,000 to 200,000 tonnes are under construction. These plants can be very well justified as suppliers to a local market. Fluting is the corrugated paper that separates the two liner plies of corrugated board. The standardized basis weights are 112, 127 and 150 g/m2. The important characteristic of fluting is stiffness, which is required in the machine direction to prevent "flat" crushing of the board and in the cross direction to give the board rigidity. In proportion to its weight, the fluting has more influence than the liner plies on the rigidity of the board. It is therefore not practical to combine a high-quality liner with a low-quality fluting. The two should be of matching qualities. Paperboard The basis weight at which paper becomes paperboard is not strictly defined, but above 225 g/m2 we are definitely talking about board. Solid board is made in one layer, usually on a conventions Fourdrinier paper machine at basis weights of 150 to 300 g/m2. The products are often custom made to fit the needs of a certain converter and are produced in small quantities. Baled pulp is used but can be supplemented by fibre from waste-paper treatment plants. The activity could be well suited to a developing country. Folding boxboard is used, as the name implies, for boxes. The usual basis weight range is 200-400 g/m2 and the board is built up from at least three plies. The idea of such multi-ply boxboard is that each constituent should be where it is best needed and that the total furnish cost should be the lowest with which the quality specifications can be met. The economy of a boxboard plant depends to a large degree on the success of its management in pursuing these objectives. In the 1970s several folding boxboard machines in the capacity range of 100,000 to 150,000 t/a have started up, and the result has been a large overcapacity of coated boxboard, and very keen competition for sales. At V4 the other end of the scale there are small machines running perhaps 50 metres per minute (m/min), and turning out 1 (),()()() t/a of paperboard. Both have their justifications. The large machines will control the market for all standard grades, while the small machines can offer products tailor-made for small converters or special purposes. Traditionally, the small board machine featured four to six so-called cylinder formers, each forming one ply on a rotating wire-covered cylinder submerged in a dilute fibre suspension in a vat. Such cylinder machines are inexpensive and easy to operate as long as the speed is not pushed above 90 m/min. Today, the machines have been further simplified and improved. The labour cost per tonne of board for such low-producing machines will be so high as to be a serious drawback in industrialized countries, but this fact should be of far less consequence in a developing country. Sack paper Sack paper is made in the basis weights 60, 70, 95 and 105 g/m2. Sack paper can be impregnated or coated with various chemicals or it can be laminated with a plastic film (polyethylene). In industrialized countries, sack paper is made only from unbleached softwood kraft pulp. Since a sack paper machine is usually restricted to one product and the pulp quality is of deciding importance to the sack paper quality, integration with a pulp mill is highly desirable both for economy and for paper quality. Appropriate technology for a low-cost paper project to stimulate the rural economy T. Jeyasingam'' Developing countries largely depend on imports of paper from countries that produce pulp from coniferous woods. In view of the increasing demand for paper and paper products on a world-wide scale and the restrictions placed on paper-exporting countries by ecological considerations and the high costs of labour for wood extraction and of transport, the present sources of supply of pulp, paper and paper products cannot be fully relied upon over the long term. Consequently, developing countries must explore the possibilities ol using indigenous fibre resources, mainly agricultural residues (see the accompanying table) to meet a greater portion of their own requirements. In a developing country where industries are primarily agriculture oriented, the manufacture of liner board and corrugating medium should receive priority over other grades. Rural economies require corrugated containers for packing and transporting agricultural produce to both domestic and export markets. The soda process has been found to have advantages over all other processes for the production of both liner board and corrugating medium from agricultural residues owing to its simplicity, sulphur-free cooking and economic advantages. It is therefore appropriate for developing countries. One suggested change in the technology normally used in developing countries is cooking at atmospheric pressure. Instead of cooking agricultural residues in pressure-type digesters using steam at 6 to 7 kg/cm2, pulp suitable for packaging grades such as liner board and corrugating medium could be cooked near atmospheric pressure at temperatures of about 85° to 1(M)°C. The digester used is somewhat similar to the multi-tube horizontal digester. Since this digester is designed to operate at very low temperatures and pressures, its capital cost is relatively low. It is compact and requires little building space. It operates economically because of its low steam requirement. In addition, a high percentage of black liquor gets recycled, reducing the pollution load. The proper scale of operations for such a process in a developing country would be a maximum of 80 to 100 t/d. This scale of operations is appropriate to the usual pace of collecting and transporting of agricultural residues. The •Pulp and paper consultant, Longview, Washington, United States of America. 95 estimated capacity of a pulp mill to produce 80 to 100 t/d of paper-board as part of the fibre furnish, along with waste paper and imported long-fibre pulp, would be approximately 50 t/d. Of the four possible paper-forming systems in present use, open-wire forming on a Fourdrinier machin- offers the widest flexibility and simplest operation. Its draining capacity is ilso much larger than that of other forming methods. In a developing country the Fourdrinier must be more flexible than in a developed one, mainly because of market conditions. For example, a developed country would make liner board and corrugating medium on separate machines. Developing countries, on the other hand, will have to make the corrugating medium as well as all grades of liner board, such as kraft liner, jute liner (cylinder liner) and bleached kraft liner on one machine. The machine features required would therefore have to cover wide ranges of grades anc' of basic- weights (that is, from 60 to 130 g/m2 for corrugating medium and 100 to 300 g/m2 for liner board) Experiments show that the effluent of paper mills, if properly treated, can be used for irrigation. Land requirements are about 40 to 50 acres per million gallons per day of effluent, or 4.3 to .5.3 ha per 1,000 m3/d. The combined effluent of the pulp-mill and paper-mill is given a primary treatment to remove suspended solids. This is generally done by sedimentation; usually, for irrigation purposes, a secondary biological treatment would be unnecessary. After the removal of suspended solids, the waste water could therefore be used for irrigation during the dry season when the farmers' demand for water is high. During the rainy season when there is no demand, the effluent could be effectively mixed with the storm water and discharged with no ill effects into the environment. In most mills in industrial countries the suspended solids and sludge are used either as land fill or incinerated after a process of thickening. In developing countries however where there is a need to stimulate the rural economy, this AGRICULTURAL RESIDUES AND CROPS CONSIDERED SUITABI F FOR PAPER MANUFACTURE Residue or crop Paper grade Bagasse Newsprint, writing and printing papers, kraft grades, hrown board and other types of board Straw (wheat, rice, barley, oats) Wr.ting and printing papers, liner board, corrugating medium and other types of board Maize stalks Liner board, corrugating medium and other types of board Sisal Hard tissues, cigarette tissue Sunflower stalks Liner board grades and corrugating medium Cotton stalk Corrugating medium Date palm leaves Brown board, bag paper Banana stems Hard tissues, speciality grades Pineapple leaves Liner board and corrugating medium Common hemp (Cannabis saliva) Hard tissues, cigarette paper, speciality grades Sorghum (Sorghum vulgare) Liner board corrugating medium and other types of board Sun hemp (Crotalaria junicea) Hard tissues, cigarette papers, speciality grades v/ sludge could, without going to the expense of thickening by centrifugation or vacuum filtering, be mixed with screen rejects and waste paper to produce solid board on a single-cylinder wet-board machine. The sheet thus formed could be pressed hydraulically and sun or air dried to produce heavy weight board for use in bookbinding or as suitcase boards for the manufacture of rigid boxes. Prospects for establishing viable small-scale pulp and paper industries iin developing countries^ Food and Agricultural Organization of the United Nations INTRODUCTION It is little wonder that the quest for economically viable, small-scale pulp and paper mills1 has become a matter of some urgency in recent years, particularly for developing countries. Paper is such an important commodity in the development process that developing countries naturally want to establish their own paper industries to satisfy their own needs and so reduce their dependency on outside supplies. The problem originates from the experience that the domestic consumption of paper in many developing countries is too low to absorb the output from even one mill of the capacity that is generally regarded as necessary for a viable operation. Two ways around this problem would be to export the surplus production or to consolidate a number of national markets into a single, large regional market. Both of these solutions have encountered a number of difficulties when they have been attempted. The export market has proved to be extremely difficult to penetrate, and arrangements for regional mills have proved equally difficult to bring to fruition. Because these difficulties have proved to be so intractable, the idea has grown that the only other option, that is, to build small viable mills, must be possible. The logic is hardly impeccable, bu the need is so compelling that the possibility is at least worth investigating. However, in assessing the prospects for developing countries being able to establish mills to supply small domestic markets at reasonably competitive costs, it is necessary, but hard, to avoid being so excessively optimistic that expectations are raised to unrealistic levels, or of being so excessively pessimistic that reasonable expectations are dashed. The twin risks arise from the simplifications that accompany any attempt to generalize about such a complex industry and such a heterogeneous community. Nevertheless, some simplification is necessary *A paper prepared for the FAO Advisory Committee on Pulp and Paper. Nineteenth session Rome, 31 May to 2 June 147«, document no. FO; PAP/78/Inf.6. 'As a general guide, within the class of 50-100 tonnes per day (t/d) capacity. 9S w and indeed possible. If ordinary and unspecialized paper grades are considered, it is evident that the viability of small-scale mills depends initially on the product grade and the fibrous raw material.2 BASIC PROBLEM AREAS Processes and mill size The basic causes of the problem of mill size in relation to developing countries are the economies of scale associated with increasing capacity. In general, the more complex the pulping process, the higher the capital cost of a plant of a given capacity. Therefore, it could be expected that mills based on fibrous raw materials that are easy to pulp would be the most readily adaptable to small-scale operations. This is in fact so. If we are talking about waste-paper-based paper or paperboard operations, a small-scale mill can be financially viable if local conditions are favourable. The same could apply to non-integrated paper manufacture, depending on the grades produced and, again, on local conditions. Integrated pulp and paperboard operations with secured agricultural residues fibre supply and in favourable environmental conditions could well turn out to be financial successes, especially for low-grade board production. However, as soon as we start talking about wood-based pulp and paper manufacture, the problems for small-scale operations are of a completely different magnitude owing to the complicated process requirement, especially when chemical pulp is concerned. The economies of scale here play a really important role. It is not difficult to build a small-scale technically viable wood-based pulp and paper mill, but it is the economics which will raise enormous problems. However, wood-based pulp and paper, and particularly chemical pulp, cannot be ignored simply because of the high capital costs associated with its manufacture. For one thing, wood is the only fibrous raw material available in sufficient quantity to support the world demand for paper. It is, in fact, quite often the only raw material which many developing countries have or could grow in abundance. In addition, the technical specifications for many paper products can only be achieved with a large proportion of chemical wood pulp in the furnish. It is thus the chemical wood-pulp side of the industry in which the prospects for small-scale mills are the most crucial. Wood pulping can be divided into two main categories, mechanical and chemical. From the process point of view, mechanical pulping is very simple, and for small-scale mills the traditional stone-ground wood process is best suited due to easy operations and maintenance as well as relatively low power consumption. However, stone grinders can be used only for logs; for sawmill residues, the refiner process must be applied, employing either non-pressurized refiner or the more recent pressurized thermomechanical pulping processes. 2ln this connection it must be mentioned that some non-wood fibres such as abaca, sisal and various bast fibres could form a basis for viable small-scale plants producing high-strength speciality papers. 00 Between the mechanical and the chemical pulping lie the chemi-mechanical and semi-chemical processes, which could produce lower-grade papers and board«, perhaps at relatively low capital and environmental-control costs. In chemical pulping, the cooking process requires a rather high temperature, pressure and chemical concentration. For economic and environmental reasons, the cooking chemicals have to be recovered. This complicates the overall process design to the extent that a bleached chemical pulp and paper mill, which includes preparation of bleaching chemicals, i? one of the most complex plants in the chemical industry today. This is the reason why wood-based pulp and paper mills are so capital intensive. All the various process stages must be included in any mill, whether small or big, for the plant to be both economically viable and environmentally acceptable. This is the situation today; no simpler and less capital-intensive processes are yet proven on a commercial scale. There might be some new developments at the research stage, but there is no indication today that they would revolutionize pulp and paper manufacture or reduce capital cost to any great extent. Equipment Because of the corrosive chemicals and high temperatures and pressures employed in may stages of the process, expensive equipment must be used. Practically all operations dealing with pulp, after the fibrous raw material preparation stage, involve liquids, which means that much pumping of liquids, filtrates and pulp slurries is required. To accomplish this, pumps, pipes and electric motors are needed, hence labour-intensive operations such as moving materials as manually possible in the mechanical wood industries cannot be employed in the pulp and paper industry between the fibrous raw material preparation plant and finishing and the handling of products. Energy A factor which affects mill designs today is the high cost of energy. For this reason, the means used in the past to reduce capital costs such as not installing heat-recovery equipment, not using heat exchangers for heating cooking liquors, low heat-efficiency boilers or a small number of liquor evaporation stages would result in high operating costs. Environment Pollution abatement for new pulp and paper mills is now regarded as universally essential even in developing countries. There are very few countries that would permit a mill to be built with no pollution abatement at all; in the future, it is anticipated that increasingly stricter standards will be enforced. Small-scale mills have a disadvantage, compared with larger mills, in that the IDI economies of scale exert a very strong influence on the cost of pollution-abatement systems. Economics As mentioned in the Introduction, economic factors are the most serious ones affecting the establishment of small-scale wood-based mills. There is very little that can be done about this fact of life; subsidies in one form or another are the only salvation. However, the socio-economic benefits of the mill could well balance them. TECHNICAL ASPECTS The purpose of this section is to review an integrated chemical wood-based (sulphate) pulp and paper mill, department by department, to find out where it would be possible to cut corners to reduce the mill capital cost. The wood-based sulphate pulp mill has been selected because the sulphate (kraft) process presently is the dominating pulping process in the pulp industry and is not expected to be replaced by any more feasible process in the near future because it produces the highest-strength pulp which is required by all developing countries irrespective of the possible local production of low-strength pulps from agricultural residues. Wood preparation This is perhaps the area where labour-intensive operation could be employed to replace machinery to a greater extent than anywhere else in the mill, since it involves the handling of a solid material, namely wood. If the logs are small enough, this may allow manual log handling from the transport vehicles to the wood storage and from the storage to the debarking and chipping operations. Debarking may also be carried out manually, but from there on all handling of chips must be done by machines. A possible saving of capital in chip handling could be achieved by eliminating the expensive outdoor chip pile and using instead a rather small buffer silo between the screening and digester plant. By doing this, however, any longer breakdown in the debarking or chipping operations would cause chip shortage in the digester plant and thus lower the operating efficiency; otherwise, the buffer silos must be rather large and hence expensive. Also, there might be the need to operate the debarking and chipping plant 24 hours a day, seven days a week, instead of for the usual two shifts and five to six days a week. This continuous operation would possibly be the best solution from the capital cost and employment points of view; at least, the debarking and chipping plant would be smaller and less expensive, and additional employment would be provided. If sawmill residues were available either from integrated sawmill operations or purchased from outside mills, the pulp mill capital cost would be reduced by a significant amount, and the operating cost would also be lowered. 102 Pulping departments The pulping departments are usually considered to include the digester plant, washing, screening and bleaching. It is obvious that a small-scale pulp mill for developing countries cannot be designed according to today s modern, sophisticated digester plants. What can be done to reduce the capital required? 1 he obvious answer is to go back to digester plants as they were 30 to 40 years ago with a simple non-automated design that would require minimum skills tor operation and would be easy to maintain. Th.s means that batch digesters would be employed equipped with manual controls and minimum basic instrumentations required for safe operation. Capital cost could be reduced by leaving ^ the pre-he a en, although this would increase energy consumption, the size ot the bo.lcr tttu water treatment system and its operational cost. The blow heat-recovery system could be eliminated but, again, this would mean increased energy costs and heavy air pollution as well. In warm climates the digester building would be semi-open, with only the operation floor fully covered. Pulp washing in modern mills is accomplished partly in the continuous digester, if one is used, followed by rotary filters or continuous diffuser washers or in the case of batch digesters, on the rotary filters or in continuous diffusers. The washing is done in various stages, and the strongest fraction is pumped to the chemical-recovery operations. In a small-scale mill having batch digesters, the choice tor the washing system is between rotary filters, the recently developed continuous dit user or old batch diffusers. The continuous diffuser could possibly be stripped of the present sophisticated process controls to be predominantly manually operated. The advantage of this system over rotary filters would be the much lower structural cost and lower energy requirement for liquor pumping. However, old batch diffusers could well be the lowest-cost solution of all and safest in the operation. In the climatic conditions prevailing in most developing countries, very little of structures would be needed and the energy consumption would be low If properly designed, maintenance would be minimal as well as the need tor SPar The next operation, screening, is usually made on rotary centrifugal screens at rather low consistency. It is becoming increasingly common to employ a so-called closed system in which screening takes place before the last washing stage to reduce water consumption in the mill; no fresh water will be added in the screening operation. For a small-scale mill, a similar system should be employed because it would reduce water consumption and thus reduce capital and energy requirements. . Modern bleach plants are equipped with extremely sophisticated process controls, including increasingly computerized systems so as to reduce manpower, optimize the use of bleaching chemicals and improve quality. Owing to competition, pulp brightness has reached levels unnecessary for most papers produced from this pulp. This is obviously not the path for developing countries •o follow with their domestic oriented mills; therefore, the bleaching sequence can be simpler and avoid the use of the expensive chlorine dioxide necessary to attain a high brightness. For a small-scale mill, this is even more important; even loi a simple system using hypochlorite in chest bleaching could, in many cases, produce pulp of sufficient brightness. Such a mill could import relatively cheap hypochlorite and avoid the establishment of a costly electrolytic plant to produce chlorine and caustic, which in many developing countries are not available locally. Chemical recovery The cooking chemicals must be recovered and returned to the process to make modern pulp manufacture economically viable and environmentally acceptable. The recovery process is complicated, involving many chem.cal processes and high pressures and temperatures. The recovery boiler is one of the most expensive single pieces of equipment in the palp mill. Because of the corrosive chemicals and the high temperatures and pressures employed, the construction material is expensive. For the same reasons, the operation of the recovery boilers has some serious hazards; therefore, modern boilers are equipped with very sophisticated process-control systems, which again increase the cost. Much thought has been devoted to what could be done to reduce capital cost in this very expensive stage in chemical recovery, especially for small mills. No satisfactory solution has yet been found. The use of low-pressure boilers would reduce the cost, but it would also reduce the amount of electrical energy generated. It has been proposed and even done in some developing countries to go back to old-fashioned low-heat-economy chemical recovery systems. In these systems most of the chemicals could be recovered, but no heat would be available outside the recovery cycle. This would mean very high energy costs for the mill, as well as higher chemical costs than for a mill provided with modern equipment. Development work in the field of recovery boilers is going on in the industry to simplify boilers and reduce hazards in the operation. It remains to be seen whether this research will produce any benefits for small-scale mills. In the causticizing plant, recently developed new equipment has eliminated some of the cumbersome and expensive clarifier tanks, thus reducing capital cost Unfortunately, however, the operation of this sophisticated equipment requires skilful operators and an ample supply of spare parts and can therefore hardly be recommended for developing countries. What can be done for a small mill to reduce the cost of the causticizing olant^ The first item which could be eliminated is the green liquor clarifier, but only if the mill produces unbleached pulp. As far as the rest of the equipment for this department is concerned, there is not much that can be done to cut the cost; however, savings can be made by combining some clanncat.on and washing functions in the same tank; this is already done in many large mills. The next obvious place for capital saving is the lime kiln. If purchased lime is available, it can be eliminated, but this would increase the operating cost, and there could be a problem in finding a dumping place for the lime mud. 104 Paper manufacture Modern paper machines are very sophisticated and are equipped with modern process control devices. At present they are usually computer controlled to save labour and improve quality. It is obvious that these are not the machines to install in a developing country where the skills to operate and maintain them are not easily available. They certainly are not for small-scale mills as they are too sophisticated and expensive for the low production rates required. What could be done to save capital and still keep the machines reasonably efficient for small-scale mills? Because of the scale of the operation, we are not considering any high-speed machines. This eliminates the need for a sophisticated drive. The speeds with which we would be concerned could be only around 300 metres per minute (m/min) and, if the machine is narrow (3 m to 4.5 m, depending on the paper grade), a simple open gear drive could be employed, perhaps powered by a steam turbine. At the speeds considered, even an open simple headbox could be satisfactory. Owing to the high energy cost, it is not advisable to eliminate the hood and the heat recovery system of the dryer section. Some capital saving could be achieved if the machine were located on the ground floor, but this would cut down the machine efficiency and cause many operational difficulties. On the other hand, these savings in capital cost would mainly relate to structures which would be predominantly paid in local currency and would therefore no reduce foreign currency payments. One problem with these simple small machines is that not many paper machine manufacturers produce them. The paper sheeting operation in modern paper mills is fairly well automated, but in small-scale mills there is no need for this. Only very simple low-cost equipment would be needed if the sorting and packing is done mainly manually. This would provide employment for women, because it requires no great physical strength. Service departments Steam and electricity Not even a small-scale mill can operate without steam and electricity. In addition to the steam generated by the recovery boiler, more is required tor the process and, because of the scale of the operation and perhaps lesser use of heat-saving devices, the additional steam requirement is greater for a small-scale mill than for a modern sophisticated one. An auxiliary boiler fuelled with bark, sawdust and possibly by firewood is needed. The use of gas or oil as the only fuel would lower the capital cost owing to the simpler boiler design, but it would most likely be more expensive to operate. If electric power must be generated at the plant, steam must be generated a relatively high pressure and temperature to produce it at a reasonable cost. If all power must be generated, two steam turbogenerators, a back-pressure unit and a condensing unit would be required. In addition, diesel power generators for the mill start-up would be needed. All these are expensive but unavoidable. 105 Water supply The water supply would be from a river, a lake or wells. All that can be done to reduce the cost of the water supply is to reduce the amount needed. Even a small-scale mill, if properly designed, can have a low water consumption, but it would still be of the order of 100 to 150 m3/t produced in an integrated mill, which would mean a daily consumption of 10,000 to 15,000 m3 for a 100 t/d mill. Possibly the water requires expensive treatment before its use in the process. Feed-water for the boiler plant must be especially treated so as to obviate expensive maintenance or even hazard for the boilers. All of this adds to the cost. Pollution abatement Present pollution-abatement regulations add 10 to 20 per cent to the plant capita! of any mill built in developed countries, depending on the degree of treatment required. Although developing countries do not necessarily follow the regulations established for developed countries, the lime will obviously come when they will comply with at least a minimum of the effluent pollution-control regulations. If the plant is located close to a river with high year-around flow or on the ocean front, the treatment required could be rather simple and involve relatively low capital costs. The primary stage of the treatment to eliminate the solids could well be enough, especially if internal measures to recover fibre and liquor spills in the mill are incorporated in the mill design. The extent of the treatment required must be studied very carefully for any new mill. As far as air pollution is concerned, a mill to be built in a developing country has no great problem and, if the government and local population agree, it can be completely ignored. Air pollution in the form of odour from a sulphate pulp mill is mostly owing to the hydrogen sulphide, methyl sulphides and mercaptan released, which are not harmful to humans or vegetation in the concentrations emitted. The dust from the lime kiln, if not recovered, can become a nuisance for the surroundings, as well as the dust from the boilers if no dust-collection systems are used. It can be said that air pollution is the smallest problem in establishing a small-scale pulp and paper mill. Process controls Modern mills are highly automated; a few operators control the process from the control rooms equipped with the most sophisticated computer controls. This is done with the aim of improving the quality of the product, optimizing the use of the raw materials and lowering the labour cost. Obviously, this is not the pattern to be followed generally by developing countries in establishing small-scale operations. The aim must be to produce a reasonably good product at an acceptable cost and provide employment. Starting from here the answer is very simple: provide only the process controls needed for safe operation and use manually operated valves instead of remote controls when appropriate. The saving in capital cost would not be a very high percentage of the total mill cost, but it would reduce the maintenance and limit the number of spare parts ¡Oh required, thus making the mill operation more efficient because of reduced shut-down time. Structures Owing to the warm climates of most developing countries, the structures housing the operations need not be as extensive as in the major producing countries where the climate often is severe. However, if there is no need for protection against cold, there is a need for protection against rain, wind, insects and, in some cases, sand. It is therefore not possible to build all departments without protective housing, although such departments as wood preparation, evaporators, causticizing and the kiln can be built outdoors. Also, many operations require more than one floor, so the cost of these structures is not negligible even if the local building costs are low. In some regions special provision in the structures against earthquakes must be included, at additional cost. In addition, an experienced local construction company is very seldom available, and a foreign company must be brought in at least to supervise the work of the local contractors. ECONOMIC ASPECTS As mentioned earlier, the basic problems in establishing small-scale mills are economic. The technical aspects which could affect the economics have been briefly reviewed in the previous section. It can be seen that savings in capital costs could be achieved by stripping the mill of equipment such as some energy- and chemical-saving devices that are not absolutely essential for the operation, but this would increase the operating costs unduly. The influence of the economies of scale is so pronounced in these types of mills that small ones may be financially sound only under very specific circumstances and may usually require protection in one form or another. Socio-economic benefits, however, could be so important to the country that a financially non-viable operation might be justified. It is also worth remembering that the economics of a pulp and paper mill could be greatly improved by integrating it with mechanical wood products manufacture, especially with a sawmill. DISCUSSION The purpose of this paper is to provide some points for discussion on this important question: can viable small-scale mills be built in developing countries and, if so, how? In the case of simple processes involving waste paper and agricultural residues, the answer could be positive, as well as in certain conditions with operations based on mechanical wood-pulp. A positive answer is much less likely with paper manufacture based on chemical wood-pulp. It would largely depend on the ability to reduce the capital cost without increasing operating costs too much. IO' It would thus appear that, with present techniques, there are only limited means to reduce capital cost. The only effective way to cut the corners would seem to be to go back 30 to 40 years in techniques and build the type of simple mills used then, although to do so would result in increased operating costs. The advantages of these simple mills would be increased employment, relatively easy operation of the plants and lower demand for spare parts, which could be partly made locally either in the mill maintenance shop or in local machine works. A very important aspect would be reduced need for highly skilled operators and thus reduced neeH for training. However, the mills should be designed initially so that energy- and chemical-saving equipment can be added later when the enterprise considers it to be economically advisable and can afford it. If all of these measures are taken and if the operation is well managed, a profitable enterprise could materialize without heavy government subsidies. Paper, paper products and pulp mills A. Western* CONSUMPTION STATISTICS There is a correlation between the consumption of paper and the standard of living for any given country. Higher levels of education, particularly technical education, are necessary to raise the earning capacity of the general population. Availability of paper is an essential factor in achieving these objectives. Recent statistics [1] indicate the wide range in per capita consumption of paper throughout the world: Consumption per capita, /977 Country (kf,/a) North America Canada 191.4 United States 273.1 Europe Albania 5 Sweden 195 United Kingdom 123.8 Average1 $\ 4 Of 41 listed countries in Asia and Oceania, only three, Australia, Japan and New Zealand consume, per capita, over 100 kg/a and only three others exceed 40 kg/a. Excluding these, average consumption (on the same basis as above) is 6.1 kg/a. On a true, population-based calculation the average would almost certainly be much less, because the values given for such highly populated areas as India and Indonesia, for example, are 2.1 and 2.3 kg/a respectively. In Latin America none of the 28 listed countries attains a per capita level of 100 kg/a and only four exceed 40 kg/a. The average is 22.3 kg/a. In Africa, with 44 listed countries, no statistics are available for two countries but of the remainder only South Africa exceeds 40 kg/a. This is not representative because the minority white population is almost certainly responsible for the greater •(Retired) Chief Executive of Reed Engineering and Development Services Ltd., Maidstone. Kent, United Kingdom of Great Britain and Northern Ireland, and consultant to Intermediate Technology Development Group Ltd., London, on behalf of which this paper was prepared. »The arithmetic mean of the published figures. This is not a true average because population factors have not been taken into account. For the purposes of this paper it can be considered as representative. I OH /w proportion of consumption. The average for the 42 African countries for which statistics are available is 3.9 kg/a. MINIMUM OBJECTIVES It is difficult to determine what is the minimum for reasonable development. The levels of 100 kg/a or above obtained in developed countries contain significant quantities of paper used for packaging and cosmetic purposes which are not essential but arise from higher living standards. A level per capita of 30 kg/a appears to be the minimum to achieve literacy, adequate communication and educational levels; 40 kg/a is a desirable objective, however, because it allows some element of packaging for industrial or export purposes. Such a level would be less than 25 per cent of the North American minimum or 45 per cent of the European average. If thé lower (30 kg/a) basis is accepted, it should be recognized that it indicates a fifteenfold increase for countries such as India or Indonesia, an eightfold increase for the African continent and a .50 per cent increase for Latin America. At current population levels it would require the total world production to be doubled to meet this objective. Taking into account population growth and the time factor, attaining such an objective would mean trebling world production, even assuming that the more developed countries remain around present levels with no further appreciable growth. The implications are staggering and pose several questions. What fibre resources will be required? How can the machinery requirements be met? What is a practical time-scale? Will current methods of production satisfy such objectives? Should some alternative to paper as a means for raising educational standards be sought? Can the recognized "modern" plant and machinery resources cope with this enormous potential demand? These questions are not academic and the answers cannot safely be left for unplanned, haphazard evolution. It is no exaggeration to state that world peace will depend, in some degree, on achieving satisfactory answers. FIBRE RESOURCES After considering population and consumption, it is estimated that for the developing countries to reach the minimum target per capita of 30 kg/a would require some 100 million tonnes per annum (t/a) of additional production immediately, doubling current world production. This allows for extensive recycling as practised in developed countries. In assuming the majors uses for such increases are writing and printing grades plus newsprint, the indications are that approximately 30 million t/a of long-fibre material as pulp and 70 million t/a equivalent short fibre, hardwood or similar, would be necessary. The latter presents no insuperable difficulties in availability, but considerable problems in exploitation. The former presents great difficulties in availability and exploitation. The capital intensity demanded for exploitation by modern standards would be prohibitive for most developing countries and the scale accepted as economic would be difficult to absorb domestically. Il» Exports of finished material can be ruled out as a practical alternative because of the intense competition from developed countries already producing for export. Export of raw or semi-finished material is at best only a temporary expedient because it confers the greatest advantage on the already developed countries, still further widening the gap in industrialization and retarding the advance in living standards. Some developing countries recognize this already and are attempting to control the export of raw or semi-finished materials. The history of paper development shows dominating principles: (a) To be truly viable and endure, paper must always be produced from a waste material of low intrinsic value; (b) The highest value which can be accepted for paper-making materials at present and expected levels of consumption is the equivalent fuel cost, value for value delivered, in the country concerned. Waste materials With temporary exceptions only, all the materials used for paper manufacture have come from discarded or waste materials. Nothing is, or should be, produced or grown simply for the manufacture of paper. Rags, straw and bagasse obviously follow this principle; so does recycling waste paper-now approaching 30 per cent of the consumption for developed countries. The same claim, indirectly, can be made for pulp produced from wood. Similarly, the initial forests were either cleared for development or exploited for timber and sawmilling. There was therefore a surplus of timber, available at very low cost; its disposal for pulp production coincided, at least in North America, with the need for its removal for land development. Admittedly, the tremendous growth in paper consumption led to the exploitation of forests for paper products alone but this was initially confined to small-tree forests less suitable for production of timber, and it was minimized by the development of chemical pulp using chips, a by-product of the sawn timber industry. It is significant that groundwood, from whole trees, has now been reduced to a very low level of production by being replaced by refiner or thermo- mechanical pulp from chips. In some areas, notably British Columbia, use of whole logs is actually forbidden for pulp production; surplus chips only are used. The development of the cant chipper for mass production of standard timber sizes with chips as a by-product is another indication of this trend. The truth is that the paper industry cannot afford the whole-log concept for raw material. It must be based on waste or by-product materials for long-term survival. Existing industries based on whole trees are anachronistic and obsolescent. In line with this, new pulp mills are normally linked with timber mills. Equivalent cost of fuel The materials used as fibre for the production of pulp and paper are combustible by nature. Wood was extensively used as fuel before it was adopted for paper making. Bagasse is the normal fuel for the sugar-cane industry and is sold for paper production on an equivalent fuel linked basis. Even waste paper is /// now seriously being considered in some areas of the world as a fuel for central power generation. The fourfold increase in fossil fuel prices in recent years and the prospects of diminishing supplies in the foreseeable future are generating ever-increasing interest in alternative fuel sources; this must have a bearing on plans for the manufacture of pulp and paper for developing countries if they are tt) have a long-term value. It has already been established that it is more economic to use waste wood from the forest as fuel for the paper industry than as a raw material for production provided that the distance from the pulp or paper mill is not greater than 35 miles (50 km) in countries with fossil fuel resources. The economic distance increases for countries less fortunately endowed and will increase for all countries as fossil fuel becomes more scarce and more expensive. In other words, the close relationship between fuel prices and the cost of raw materials for pulp and paper production must be taken into account for long-term planning, and it should also be recognized that capital-intensive pulp and paper mills are truly viable only on a long-term basis. Paper machines commissioned between 50 and 80 years ago are still operating in many areas of the world. This time-span, which can be expected to apply also to new industrial installations, will exceed that forecast for the availability of fossil fuel resources at present consumption rates. If the above principles are accepted, pulp and paper manufacture for developing countries should be based on raw material waste from associated timber or agricultural industries, and it should recognize the growing value of and the ultimate competition for such materials as fuel. This means that wood-based pulp should, wherever possible, be associated with the timber industry. Bagasse and straw already satisfy the essential raw material conditions. Reeds, bamboo or other grasses with no other commercial use are more suspect; they should be considered only where profusion exists, labour is cheap, land development and clearance is a feature, and where more permanent materials can be expected in due course to replace them economically. As the standard of living increases, labour costs will also increase and the conditions that initially enable a pulp and paper mill to be established may change unfavourably. Transport costs will also increase disproportionately as fossil fuels become more expensive. Generally, with the possible exception of long-fibre softwood pulp, sufficient raw material resources exist in most areas for an effective start on the targets specified. Over the time scale involved it should be possible to get much nearer to self-sufficiency especially if recycling is employed. For this, however, a strategic, planned approach is advisable, if not essential. The planning should take account of all factors involved: forest resources, agricultural resources, population centres, human skill resources, ecological conditions, power and fuel resources, plus other considerations. The dogmatic assumption that "modern" technology and economic scale considerations can be imposed successfully on developing countries is open to criticism. As it stands, the pulp and paper industry throughout the developed world is not a shining example of unqualified success, and those concerned should not pass on to underdeveloped countries their mistakes in the name of advanced technology. 112 MACHINERY AND PLANT CONSIDERATIONS Over the past 70 years the size of the paper machine has increased from approximately 2 m in width to around 10m; operating speeds have been improved from about 100 metres per minute (m/min) to 900 m/min (1,250 m/min for tissue machines). In 1927 the largest and fastest machine in the world was commissioned in the United Kingdom. It was 5.3 m wide and capable of operating at speeds of up to 250 m/min. In 1937 the largest machine in the world was just over 9 m wide and capable of operating at speeds of up to 425 m/min. Both of these machines were designed primarily for newsprint production, and each is still in operation but not producing newsprint. Printing and writing papers have been substituted with the help of relatively minor modifications. The significance of this statement is not so much to prove that even greater widths and speeds are essential for the economic production of newsprint but to show that there is much greater versatility in the product range of a paper machine than is generally recognized. In fact, most of the earlier, smaller machines were originally designed for newsprint production and those still in operation (a considerable proportion) are making other products over quite a wide range. In terms of annual productive capacity of newsprint, the single machine has moved from approximately 5,000 t/a to over 150,000 t/a. While these figures illustrate progress in terms of mechanical achievements, to assume that the changes have brought about more economic production would not be justified by the facts. In pounds sterling (because both of the machines noted above were of British manufacture) the costs of the machines since 1937 have increased 50 to 60 times in terms of width and around 30 times in terms of annual cost per tonne of product, taking into account the speed difference (which at the higher levels are seldom achieved consistently). Over the same period, the selling price of the product, newsprint, has increased 20 times. One would have expected the reverse to occur but the facts disprove it; in other words, it is becoming less and less economic to invest in new paper machines except for special circumstances. In terms of a complete mill over the past 25 years, the annual cost per tonne has increased tenfold and the selling price of paper has only tripled or quadrupled (excluding pulp manufacture). If this is progress, the industry would be better off without it because, over the same period, interest rates have also more than doubled. As a result, investment for new machines in countries not endowed with low-cost raw material resources has been drastically reduced. Production is maintained by upgrading products and keeping outdated machines operating. This is economic under such circumstances because the sheer cost of money for new machines now often exceeds the profit margin available from the sale of the product. The quantity of money required is also such that, after tax, private investment simply cannot support the burden from reserves: only governments or transnational companies can raise the funds required. It is no argument to say that this state of affairs is consistent with world trends. If investment is not viable for small industry, it is only viable for large industry or governments after a sufficient time has elapsed for the money burden to reduce and selling prices to increase. Until this state of affairs has been realized, there must be losses. It is worth examining this situation in detail to avoid arriving at the same accept imports as the practical Limi »f î "" acceP,abl<: standard. To C S 5 wi bc h availability lower nd the baL'l 'f" " ""*"''* ° ' " W*'. expanston, investment in a new plan, cannot oeTuSfjltI , !," raP'd however, apply ,o such primary users of „„ * 1 ' Th' sl,ua"on does not, papermaker itself.or carton manufacturer nd snould'noTapo>»«uiu not apply v to„ ,£"the manufacturer ' T*""' of ^ the foHo^arTstSn" * reaS°nS ^ *"" SÍ'Ua,Í°n haS »• «<»« and the Ptolf!S•rXrÄ" '"e manufacturing costs and selling pressure on „„tÄtS "^ "^^ °',he «'"""^ a effecfonte ft ^ J»"* » *" «* •« •- depressi„g *4ÄJEÄ^;lab0Ur COn,r01' C0St and effi—y -rease (d) The intrinsic cost of the machine«; npr „„;* „f ^ ÌESK* ab0Ve a 8ÍVen "^•* ^ ^^-give"^dS material costs and ancillary ccSsfo?r,la„qTd '""^ in "P^ticiion, because of the greater !7ume ,„•ived '"^ C°StS for dis,ribu'i• i«SiKrease in rergy costs has made speed iess •»»»»•«• «S "s tx rrwere askeiif ,hey cou,d p»** established in terms o"cäpi,a"cos ne li, TT maCh'ne ""P"*» to be the suppliers contacted could X .hT T Produc"on Surprisingly, none of n W h0U, C S y which they *TnZ•XU^trT " ' ° " ••W'• faster mus, be moreeconomihm , ,1 \ assumP"°" "» that bigger and available. <*onom,c, but no tacts to support this assumption were n P S 0 0 b a Vari US SÌZCS f ch from?e:e"rsuMiet a„7 ,o uS e ' he V*?"0 e,her wi,h*" re° ° • - some guidance Thé esuls wll ' « t P •us data ,o obtain machines of the FourdrTnietvoet, SUrpr,s,n8vfor """ orthodox, modern 5 m Wlde For tlssue machines, based lareelv on flrt„ai inerii • - Per day („d) the "*£ £^£^5 ^ '° '° '°° *• n d 8 8 i i0 in,0 Pera,ing effiCienCies revealed equaítTuS g fL ,•t^m osî ;fí ° """«her IN for major roll change or breakdown was least at this size and the smaller machines enjoy more uniformity of product These indications encouraged the inclusion of machines around this si/e as alterna ,ves m three serious feasibility stud.es. The first was for an o approx.ma.elv KM. 000 t/a capacity of coated, publ.cat.on-g K, p; '? > " single mach.ne 7.5 m wide with an off-machine coater of n VwEjth , units scored heavily in this aspect. smaller ing COS,S r ,hC sm ll n fact A« r?n f , "' » - »"inc concept were enhanced bv the eve al»as 7,' "***? COUld "'"' '"' markct ««»*• I« realized for o n e d tor sons unconnected doubtd oZ',r, that ,theh e smaller-unit r concept would ^^>^<::]Z have been adopted I he second case was for a mill of approximatelv -5S íMXi'i/-. ,.,«. . ba ed on imp ried Ä£W.ST H " *ää :, Wld,hh WerC C mparCd with ne TheI he sstudy, ùdv hbased t on T firm quotations, indicated" that the " best S-S-m case in¡- term«width, f capital and operational costs was presented by the two sml machmes T 8 WerC nflUenCed by ,he h rabimh abilityvrhe of the smaller,; machines. to halve "• these"Vade requirements Ze^! by selection This is ever, more likely to apply ,„ developing countries with small mafke s and a wide range „f demands. This project did no, materialize either because neithe concept presented a sufficiently attractive case at the time machar idtSnv7° S,Udiesone interesti"8 and significan, fact emerged. Two ^-al^^^^ design costs and repetitive tooling. reductions result from These results were encouraging but were not regarded as fully indicative 3 d US ,he maChini tor„ estimates•ZÄlitT of capital cost' 7r of machines ? per unit of"« production -quiremtnTst'S the studv also o estimated the cost of ancillary plant and the buildings V Similar investigations [3. 4] elsewhere confirm the findings in respect of the weigh, of metal required while establishing a sharper minimum S cÚ ve bottoming at 3 m ,n width. Both studies demonstrate tha, in terms of m"aT abncation and machining there is an optimum size for a paper maThine Tnd i falls far short of the mammoths being imposed upon the indus• na This conclusion should not be surprising. Fundamentally a paper machine is a bridge between two sole-plates-a bridge that costs more as the span increases by a non-linear ratio. The cost is further increased if speed is included as a factor because the critical speed is a function of deflection. However, the case for smaller machines and two-storey buildings is capable of even further improvement. The machining costs from established manufacturers would undoubtedly be lower if based on machine tools of smaller size. Electric drives need not to be used: they are an unnecessary expense except where high speed is involved, i.e. above 600 m/min. The greatest economy, however, arises from standardization of design and components. At present, paper machines represent individual designs and manufacture. These are not assembled or tested prior to dispatch, and the period of assembly with expensive labour together with the costs of commissioning and adjustment represent a substantial addition to prime costs of up to 15 per cent of total cost. Speed should also be considered. It is axiomatic that small machines can run as fast as larger ones. It can also be shown that, taking speed as the criterion, capital costs per unit of production reduce as speed increases. However, operating costs should also be taken into account. High speeds involve more sophistication, greater skills or experience from the operators, higher standards of maintenance and higher levels of energy consumption. The introduction of synthetic wet felts has permitted higher speeds and press loadings but the vacuum requirements in terms of power have trebled and this, coupled with the fourfold increase in energy costs, now makes speed a costly feature. The advantages of smaller machines were evident in a study dealing with a machine to produce waste-based liner board or corrugating medium at the rate of 45,000 t/a. This compared a single machine capable of operating at speeds up to 300 m/min with two former-type machines of 2.2 m width limited to 180 m/min because of the vacuumless formers selected. The study was based on firm quotations and gave the two small machines as the most economic solution. The power requirements were a telling factor, plus the ability io minimize grade change requirements. Because of this, it is now believed that the industry would benefit from the development and mass production of standard paper machines around 2.5 m in width (which would suit the largest reel or sheet size currently used) and designed for speeds of up to 200 m/min. Such machines would be versatile and could be made more so by the optional addition of one or two simple vacuumless formers. The substance range would be 40 to 350 g/m2 with the formers, or 40 to 200 g/m2 with the Fourdrinier alone. A simple mechanical drive, preferably of the turbine type because of the greater speed range and lower cost, would suffice. The machine should be designed for modular, pre-assembled construction to minimize site assembly requirements. It is not difficult to consider the entire machine house and preparation plant also as standard. Its modular construction, with pre-assembly of the preparation plant, piping, steam and power services, built-in boiler and power plant, water and effluent services, and chests would allow a truly packaged unit. No paper converter requires reels in excess of the width suggested, so the winder can be eliminated, with a simple rewinder for reclaim. The relatively low speed and width would minimize sophistication without losing quality. 116 This concept is now being studied and preliminary indications are that a paper mill designed and produced in quantity to such a specification can achieve capital cost savings of around 30 per cent. It would be operated by labour with a minimum of training obtained on identical plant and could be self-sufficient, versatile and competitive in operation costs with the giants. The annual production from such machines would range from 7,000 to 20,000 t according to substance and would suit a growing developing country market. Although to some extent the concept can be considered as turning back the clock, it would however, take advantage of genuine improvements such as the combi-press pick-up, grooved or fabric presses, substance and moisture control. The world needs cheap paper, which in turn requires less expensive machines. Production of such machines, under licence, would not be beyond the resources of developing countries, and the spare parts problem could be reduced to a minimum with substantial operating economies in terms of cost and continuity. One objection to the relatively small-capacity, standard-machine approach is that labour requirements would be increased for mills above the capacity represented by a single unit. This is not serious, because in any mill the number of machine operators relative to the total number of mill employees is small. Where labour is cheap and employment scarce, the increase may indeed be beneficial. It is also possible, if labour economy is desirable, to operate two machines with one crew. The case for large-capacity, highly sophisticated mills for developing countries should not be automatically accepted because a feasibility study has recommended it. All too often, such studies, based on modem Western technology, end with a project which is viable only if protected by tariffs or subsidies. This is not a long-term solution. Paper must be cheap and available in sufficient quantity to the poorest; tariffs and duties defeat this objective and should be regarded as a temporary expedient at best. The real objective is to be competitive against imports; ocean and overland transport costs should provide any protection that is necessary. In many areas of the developing world there will be situations which call for labour-intensive installations of a capacity even smaller than that indicated by the standard mill described above. It is a feature of developing countries that the bulk of the population, being agriculturally based, is located in villages remote from the major towns. The number of established towns relative to total population is, indeed, very small in comparison to developed countries and communications are often less than adequate. Transports costs from large mills remote from such villages are thus likely to be high and to increase with time. Local industry, based on locally available material, could be the most economic and desirable solution. Under such circumstances, mills with minimum energy requirements could provide the most practical and economic solution, and there is also a case for developing the 5- to 10-t/d unit as a standard and making it available at low cost. The standard one-reel-width installations, competitive in nature, are a must. It is likely that the potential market for them is such that mass production is a real, practical possibility. The third world cannot satisfy its existing and potential requirements by the huge tailor-made installations now presented by modern Western technology. On the other hand, the established machinery manufacturers are unlikely to initiate or support such a concept since it is 117 opposed to their vested interests and the scale of their existing machinery, nor are the major consultants likely to endorse this policy: it is contrary to their business expectations. The lead should come in an organized manner from potential customers and independent advisers The magnitude of the requirements over an acceptable time scale requires a change in tactics. Paper machines should be produced in the same manner as automobiles except that full standardization can cover the full range of ancilliaries as well as the basic machine. An effective design would attract manufacturers and is worth sponsoring. PULP MILLS Wood-based pulp It is accepted that the economic scale for a wood-based pulp mill is now 600 t/d as a minimum, with some installations as large as 1,000 t/d. Unfortunately it is more difficult to challenge this basic assertion than the corresponding assumption for paper mills. As a superficial analogy, it has already been stressed that a paper machine is a bridge, the intrinsic cost of which increases disportionately as it gets wider. A pulp mill is more like a container, where the material cost reduces with scale. The limit, in fact, is more realistically given by the washer size (where the bridge concept pertains), and this is under attack by diffusion or the newer high-consistency stacked washers. However, although this fundamental fact must be accepted for developed countries and is mandatory where export is a feature, it does not necessarily apply with the same emphasis to less-developed countries because it is based on tie principle of capital cost per unit of production relative to the pulp mill alone. Even in developed countries, no scale would be economic without a supporting timber-mill infrastructure, going right back to the forest. If a forest exists (and there are abundant forest areas in almost all developing countries) it is first desirable, if not strictly necessary, to establish a sawmill industry. Its size depends on the market it can serve. Such forests are almost exclusively natural forests of mixed hardwoods which, initially at least, restrict the timber market. The North Americans were fortunate in having both enormous softwood reserves and an exploding market for softwood timber to meet the housing requirements of a rapidly expanding population. These conditions are unlikely to apply to the developing countries to a similar extent, and the world is neither lacking in hardwood nor likely to be short of hardwood pulp. Except, therefore, where the hardwood timber species have export potential and are near enough to a port to realize it, the sawmill industry is likely to be gradual in growth and relatively small in scale. As it develops, reafforestation with softwoods will improve the situation but, although this should be planned wherever possible, there is, inevitably, a time-lag involved. It should be recognized, however, that almost 60 per cent of the total wood used for a sawmilling operation is available for pulp (particularly where cant-chipper techniques are used) and approximately 15 per cent for fuel raising, with IIS dry-barking. Where wood pulp would otherwise have to be imported, therefore, an economic case can often be made for pulping operations on a smaller than recognized scale. The recent return to static digester pulping makes it possible to consider small installations at least as a beginning. These comments apply to kraft of high-yield pulp for writing and printing papers. For semi-chemical pulp, a much smaller scale is acceptable: from 80 t/d upwards and where proximity to a forest or sawmill is not essential. Scrub wood over a relatively wide area can be used. For all pulps, of course, chemical and water resources are essential, and chemical recovery with other ecological provisions should also be incorporated. Transport of finished product to the consumer may also be a problem. From the forest exploitation aspect, activity should be based on producing semi-finished material for conversion nearer to the centres of population, the principal consumer areas in terms of final product. Unless particularly favourable circumstances apply, the large wood-based pulp mill should not include a paper mill, particularly for the printing, writing and associated grades. Unless export possibilities for other grades exist, these must be the priority grades for the following reasons: first, for some time to come, it would seem that a proportion of the furnish must be imported as long fibre, and access to a port and the avoidance of long hauls twice (first as pulp then as paper) should be avoided. Secondly, small self-contained paper mills can be located in populated areas without ecological impact if properly designed; this would be more difficult and expensive for pulp mills. Thirdly, it is always advisable with paper of this nature to be near the customer, the printer or converter, and to be able to offer quick .and effective service over the range of reel or sheet sizes involved. Fourthly, populated areas provide a practical basis for the recovery and reprocessing of waste paper as a constituent of other furnish or for wholly waste-based products. Recycling must be considered in any future planning. Finally, with industrialization and more advanced, less labour-intensive agriculture, the established centres of population will grow and new ones can be expected to emerge. Already, the migration of population from country to town is a problem for developing countries. The paper mill and the associated conversion activities are more labour-intensive than wood-based pulp manufacture and can provide employment where it is most needed. It can also centralize technical instruction and training. Non-wood fibre pulp Bagasse Where the sugar-cane industry is established, the manufacture of paper from the residual bagasse should be considered because it is almost always viable, given a home market for the product. It is competitive at relatively low scale if the bagasse does not have to be carried too far, and it has positive economic advantages if the paper mill can be located adjacent to the sugar mill to avoid baling and double handling. The problem of equivalent fuel has //y retarded progress in bagasse-based papers because sugar mills normally satisfy their process steam requirements by burning the bagasse in boilers designed for the purpose. This problem is overstated in most cases and could, with some self-financing initial assistance, be overcome. About one third of the bagasse can be returned for fuel as pith, although this may require toiler modification at the sugar mill. Alternatively, the paper mill can purchase pith-burning boilers for its own process needs. This, however, introduces problems of pith storage and there is also need for an efficient pith-burning boiler. Existing boilers are adaptations of waste-burning boilers primarily designed for other materials; they are capable of improvement in reliability and efficiency of combustion. By pre-drying pith using waste heat, for example, the fuel value of pith or bagasse can be doubled. Finally, nearly all sugar mills have a surplus of bagasse, which is disposed of by incineration without regard for steam-generating efficiency. Using available technology, bagasse is competitive as a paper-making fibre in terms of cost and quality of product. It is versatile in end use and generally requires less long-fibre support than hardwood pulps. Further development of technology for bagasse can be expected to enhance still further its desirable properties. A similar application of technical effort should also be applied to the fuel balance and utilization aspects. These undoubtedly limit the exploitation of what is probably the third world's most promising and rewarding source of fibre. With the simple soda process, chemical recovery is practical at pulp production levels from 50 t/d upwards, and paper production is viable at about the same level. Straw pulp Straw from wheat or rice is an established raw material for paper production. It has advantages in opacity but requires greater long-fibre support and is more difficult with respect to chemical recovery because of its slow draining characteristics and high silica content. For these reasons its acceptance in developed countries is low, even where there is a scarcity of other indigenous materials. For the developing countries, however, its use is increasing and several specially designed mills are operating successfully. It is suitable for small-scale operations but can be considered for larger-scale activities where market and other considerations are favourable. A continuous process can be employed, but batch pulping is more common. Other materials Bamboo, reeds, hemp, jute, flax, esparto, sisal, cotton, kenaf and other vegetable fibres can all be used for paper making. Hemp, flax, cotton and jute have particular properties which are valuable for speciality papers and could have export value. Bamboo has for many years made a significant contribution to the paper requirements of India, and considerable expertise has been developed in exploiting the use of this material, which presents difficulties not present to the same degree in other fibrous raw material sources. Kenaf has a particular attraction as offering long-fibre prospects and the opportunity for eliminating the need to import softwood. The distinction between these materials as serious prospects for a large and 120 self-sustaining industry lies in their availability. Where, as in the case of bamboo and reeds, the material is used because it happens to be available and would not be deliberately planted, their use can only be regarded as temporary even if the time-scale is long. The same applies to materials that are planted and harvested for a higher added value industry or where (such as hemp, jute and flax) the material used for paper is the prime material, not a waste residue. Cotton linter is a waste product but has an intrinsic value for higher-grade special-purpose pulp which, except where distance to a port is prohibitive makes it too good for normal papers. There is a less valuable linter element arising from the dust, sweepings and the like from cotton processing factories This has been shown by experiment to have some value as furnish components for cheaper wrapping papers, but the quantity is not large. For continuing viability, paper should be made from waste residues available in quantity from other businesses for which the basic material is mainly collected. This raises possibilities which have not so far been exploited because the cost of preliminary investigation work could not find sufficient local support Rubber-plant residues, banana stalks and leaves and coconut husks are examples where vegetable residues are regularly available in quantity and have no alternative use capable of absorbing the quantity. They can actually present disposal problems in some areas. Work could be done on these materials to establish whether or not they are serious subjects for development. Preliminary work indicates lower than normal yields and the need for the development of new techniques. Understandably, these early efforts do not inspire private investors to spend considerable sums on what could be speculation: the chances of being competitive are small for the pioneers in any field. Nevertheless, in view of the need to find in developing countries raw materials that are available in quantity as otherwise waste materials, more work should be done on these materials. Funds for such work need to come from national or international sources; they cannot be expected from the industry, which is already copine with its own particular financing problems. Pulping machinery and processes For wood-based, bagasse-based, straw-based or reed-based pulps the essential plant and processes are already developed and available. Progress in development can also be expected to continue because commercial plants based on these materials are operating successfully in many areas of the world Sufficient examples exist for studying particular problems and learning how best to surmount them..Such plants are, relatively speaking, large, covering a range from 60 to 250 t/d for the bagasse, reeds, straw etc. and up to 1,000 t/d for wood-based materials. Developed country technology has little to offer that is modern or competitive in any practical sense for pulping plant of smaller scale even though the industry was originally founded on mills of this order Yet there is a strong need for such equipment to use locally available materials in the more remote, agriculturally based village areas in the developing countries Over the whole spectrum of progress required, it may be a temporary need but it is believed the time scale would justify many such installations and that they could 121 be the nucleus for the ultimate, more permanent mills. By absolute standards they may be uncompetitive, labour intensive, and result in lower than internationally recognized standards of quality, but they would satisfy a need, provide employment and play an important part in industrialization. All these criticisms could be levelled at the earlier Western technology if it were judged by modern Western standards, but it sufficed in its time. The developing world, in many areas, has not yet reached a comparable time and needs the more primitive plant to begin with, if only to meet the human requirements for the future. If it has to wait until it can establish and operate a paper industry conforming in scale and technology with modern practice, the time-scale will be extended to a totally unacceptable degree. Fortunately, this has been recognized in some areas of the developing world, and a number of small mills are successfully operating on a relatively primitive, labour-intensive and low-capital basis. This is particularly true of India, and it is to that country to which we should look for guidance and example. TIME SCALE It has been suggested that a per capita consumption level of 30 kg/a is a minimum target to achieve the fundamental requirements for literacy, communications and as a basis to serve the needs of industrialization. This level was reached in the United Kingdom around the year 1900, so it cannot be said to be over-ambitious. Food and Agriculture Organization of the United Nations (FAO) official forecasts [5] for growth predict a 29 per cent increase in world per capita consumption in 15 years: World consumption Per capita consumption (million tonnes) (kg) 1975 149.3 37.6 1980 179.8 41.1 1990 255.7 48.4 The increase in absolute consumption overall is 71 per cent, achieved at the rate of approximately 5 per cent per annum compared to the rate of increase of per capita consumption of 2 per cent per annum. The discrepancy is due to an adjustment for population increase. The average consumption figures quoted have to be viewed in the context of developed countries' existing levels of over 100 kg/a per capita and the corresponding levels for the developing countries is about 5 kg/a per capita. The overall increase, if universally shared, would raise the level for the developing countries to around 10 kg/'a per capita by 1990, far short of the target. However, the forecast does not predict equal snaring; it forecasts an allocation of the overall increase 2xfo times as great for the developed countries as that for all of the developing countries. For the developing countries, the forecast assumes an increase from the level of 8.9 million tonnes in 1975 to 20 million tonnes by 1990, only 10 per cent of the world increase despite the prediction that population levels will far outweigh those for the developed countries. 122 It taken seriously, the forecast shows what can only be described as a hopeless, despairing situation. Nothing could more clearly demonstrate the urgent need for a change in tactics. The prediction, however, is almost certainly based on an extrapolation of modern Western technology and accepted economic forces. This does not meet the challenge; a change in strategy is needed. Assistance from the developed world using its established technology cannot be expected to suffice. It has a part to play, without doubt, but there is a further part to be contributed by a "new" intermediate technology, emerging from within the countries involved. Resources of manpower and material already exist: they must be more fully utilized by those in immediate need. The methods may not conform with accepted modern standards but the contribution is urgently required. The minimum target should be reached by the end of this century, and every available means of achieving this objective should be utilized. REFERENCES 1. Pulp and Paper International, July 1978. 2. D. Harris, The Economics of Paper Machine Design (1473). 3. E. D. Karl Schmidt, "Development trends in paper machine construction*. Das Papier, 1971. 4. K. F. Schonemann, "Optimum paper machine size in the industry of the future". Deutsche Papierwirtschaft, 1968. 5. World Pulp and Paper Consumption Outlook (Rome, Food and Agriculture Organization, 1977). Small pulp and paper mills in developing countries and their recovery systems H. H. Hackl* and L. W. P. Ehling** Not enough consideration has been given to the advantages of small pulp and paper mills for developing countries. The tendency in industrialized countries constantly to increase the unit capacity of pulp and paper mills has often been transferred to new mill projects in developing countries. This has proved to be a mistake in many cases and has led to a number of new installations, that turned out to be failures because they were not in accordance with the possibilities and requirements of the clients, countries or market conditions. What is meant by "small" pulp and paper mills? When talking about "small" mills it is necessary to first define the word. Compared to a wood pulp and paper mill with a capacity of 600 tonnes per day (t/d), à 200-t/d mill might be considered small and below minimum economic size. In most developing countries, however, a 200-t/d mill is regarded as large because most of these countries start their pulp and paper industry on raw materials other than wood. For these non-wood fibre mills based on such materials as straw, bagasse, reed or grass, a 200-t/d capacity means a large plant; the capacity of "small" mills is very often only 50 t/d or even less. This is made clear by the figures in the accompanying table, which lists all non-wood fibre pulp mills established since 1965. It shows: 23 mills of 10 to 70 t/d 10 mills of 70 to 120 t/d 9 mills of 120 to 200 t/d 2 mills of above 200 t/d Will small pulp and paper mills still be built? More than 50 per cent of all non-wood pulp mills have capacities of 70 t/d or less, with most of the smaller mills in the 25- to 60-t/d range. The market for * Sales manager, Babcock Krauss-Maffei Industrieanlagenbau, Munich, Federal Republic of Germany. ** Project engineer, Babcock Krauss-Maffei Industrieanlagenbau, Munich, Federal Republic of Germany. 123 124 PULP M1LLS BASED ON NON-WOOD PLANT FIBRES CONTRACTED WOREDW.DE Ar I tK 1965 (•'aptuin Name of mill Country Hid) Ran material Letjes Indonesia 22 Rice straw Klabin Ponsa Brazil 40 Bagasse North Bengal Bangladesh 60 Bagasse Centra! Pulp Mill India 120 Bamboo Orizaba I Mexico 80 Bagasse Pudumjee India 25 Rice straw IHigan Philippines 40 Abaca, bamboo Curitiba Brazil 25 Grass, straw Basrah 1 Iraq 70 Bagasse, reeds Banjuwangi Indonesia 30 Bamboo Valaichchenai Sri Lanka 30 Rice straw Tejke India 40 Rice straw Pakistan Paper Co. Pakistan 90 Bagasse Calumpit UPPC Philippines 50 Bagasse Pars Paper I Iran 60 Bagasse Mostaganem Algeria 180 Esparto grass Saica Spain 40 Wheat straw Sylhet Bangladesh 80+20 Bamboo, reeds, jute Isaroq Philippines 10 Abaca Saida Algeria 80 Rice straw Pars Paper II Iran 150 Bagasse Menzi Philippines 10 Abaca Embilipitiya Sri Lanka 40 Rice straw Afyon Turkey 170 Straw, reeds Stanger South Africa 150 Bagasse Basrah II Iraq 120 Reeds Nagaland I India 50 Bamboo Nagaland II India 50 Reeds Mocarpel Venezuela 150 Bagasse Olmuk Turkey 70 Straw Loreto Mexico 80 Bagasse Induperu Peru 250 Bagasse Misan Iraq 150 Bagasse, reeds Deir es Zor Syria 100 Rice straw Letjes II Indonesia 40 Rice straw Papel Periodico Mexico 300 Bagasse Samchong Republic of Korea 20 Rice straw Orizaba II Mexico 200 Bagasse Rakta Egypt 100 Rice straw Thai Pulp Co. Thailand 150 Bamboo Kastamonu Turkey 15 Cotton linters Lepenka Yugoslavia 50 Straw Kerala India 100 Reeds such small mills is mainly countries without an established pulo and mner ^S^A^T?^ míght haVe ~* — relPu?esatn dbPunPde wooa oased paper mill, but in many cases il is not possible to exnloiio s>,,-h resources economically owing ,0 the lack of the necessary infr^ructurè Many developing countries have vast resources of read av^hi. non-wood raw materia,, I, is therefore logical «ha. they ba"e heir mnîfo 125 materials such as rice straw, cereal straw, sug jr-cane bagasse, reeds, bamboo and grasses. Nevertheless, to secure a continuous raw material supply for even a 50-t/d straw pulp mill is no easy task for a new installation. Problems of raw material collection and transport often set limits to capacity. Even if collection problems can be solved, there is still a question of transport costs if material must be brought from a long distance. These problems might not occur with bagasse. There is no collection problem, and a 50-t/d mill can in most cases be supplied by the bagasse from one sugar mill. This means that raw material costs can be kept to a minimum by eliminating transport. On the other hand, the trend is to build bagasse mills with capacities around 150 t/d. For a country with little or no pulp and paper industry, it is recommended to start with a small and less sophisticated mill. After a period of successful operation, an extension or a new project of larger capacity can be added. This procedure has been successfully practised in countries such as Egypt, India, Indonesia and the Philippines, which all started small-scale mills and have thus achieved the experience to go on to larger units, ^mong the advantages, site selection for a small mill is easier and the possibility of placing it in the vicinity of larger cities is better. This brings further advantages with regard to factors such as the availability of infrastructure, recruitment of qualified personnel and availability of workshop facilities. It also means proximity to the market, with correspondingly reduced transport costs for mill products and utilities. One reason why such small mills will continue to be built is that they can better meet the market requirements of most developing countries. Sri Lanka with a population of 14 million and a total annual paper consumption of 35,000 to 40,000 t, provides a case example. It would have been a serious mistake for this country to start with a 100- to 150-t/d multipurpose pulp and paper mill, since this would have resulted in very high investment and operation costs versus low efficiency resulting from the frequent changes in grades in order to meet the low volumes of different products. Sri Lanka began correctly by starting with a 20-t/d rice-straw mill which was expanded by an additional 30-t/d line in 1968. The next step was a 60-t/d straw pulp and paper mill which recently went into production. Sri Lanka is now executing a study for an additional pulp and paper mill of larger capacity to cover another large product range of their total paper consumption. This example shows that, for comparable countries and conditions, three mills of approximately 50 t/d for different paper grades, built one by one, will prove better for a small market than one multipurpose mill of 150 t/d. Though total investment costs for three smaller mills might be somewhat higher, these costs can soon be amortized through the higher production efficiency of the small single-purpose mills compared to the larger multi-purpose mills. A further argument is that many large projects in developing countries are failing or suffering from delays of several years simply because the total cost involved for larger mills is too high to finance. A solution in many cases is to reduce capacity to cut the investment to a level at which equity capital procurement and financing are possible. 12h Main features of a small pulp and paper mill When planning a 50-t/d pulp and paper mill, it is incorrect merely to scale down a larger mill. The technologically best process and the most modern equipment are not necessarily the most economic solution for a small unit. It is, however, essential to keep such mills as simple as possible and to use conventional, sturdy and well-proven equipment. Everything should be done to keep investment cost as low as possible. Nevertheless, it is sometimes difficult to convince developing countries that their 50-t/d mill should by no means incorporate one of the well-known continuous digesters with high heat washing, an oxygen bleaching system, a fully computerized paper-machine control system or a sophisticated chemical-recovery system. The appropriate features of a small pulp and paper mill can be summarized as follows: The mill should preferably be an integrated pulp and paper mill with a pulp-mill capacity of up to 80 per cent of the rated paper production. Non-integrated pulp mills seldom prove viable. The production programme should not be too broad. In order to use the rated capacity of the mill, it is necessary to run as few paper grades as possible or at least to stay within the basic grades such as fine paper with different grammages. A small pulp mill should be designed for either bleached or unbleached pulp grades. The additional investment cost for bleaching plus the necessary auxiliary departments and facilities has an effect on economy of the mill during the period when unbleached grades are produced. Simple and well-known equipment with unit capacities meeting the requirements of small production should be used. In contrast, the most modern equipment is usually designed for unit capacities and far exceeds the requirements. This increases the investment cost and can lead to disadvantages resulting from an unacceptable difference between minimum unit capacities and actual production. Automation and control instrumentation should be reduced to an absolute minimum. Sophisticated control instrumentation results in higher investment and subsequently increases maintenance costs. The scope of auxiliary and service departments should be limited. A site power plant should also be avoided if power can be obtained from the public grid at acceptable prices. Simple, low-pressure package steam boilers should be used. Chemicals such as caustic soda and hypochlorite should be purchased rather than produced. General mill departments such as workshop facilities, laboratories and offices should only serve the minimum requirements of maintenance and production control. The mill should rely on external repair and workshop facilities for anything additional. The cooking process for small non-wood-fibre pulp mills is mostly straight caustic-soda cooking. Compared with the cooking chemical requirements for wood pulp, chemical consumption for non-wood-fibre pulp is considerably lower. For bleachable chemical bagasse pulp, the active alkali requirements are about 10 to 12 per cent, expressed as NaOH and referred to as raw material input at a digester yield of 52 to 54 per cent. Figure I shows the different plant departments of a typical integrated 20- to 70-t/d pulp and paper mill based on bagasse. A mill with these departments will require an investment cost as shown in figure II. There may be deviations from the indicated investment cost in specific cases, but these diagrams serve as general guides for the financial magnitude of such projects. In addition to the environmental aspects, the loss of the cooking chemical is still one of the arguments against a small pulp mill. Owing to reduced chemical input, these losses do not affect the production cost to the same extent as they would in the case of wood pulp. There are, however, developments which may help small-scale pulp mills to solve the chemical recovery problems cheaply and reliably. One simple and cheap chemical recovery system was to go into operation at a 40-t/d rice-straw pulp mill at the end of 1978. It is described later. Budget prices for small integrated pulp and paper mills Figure II shows budget prices for small integrated pulp and paper mills When inspecting it, the following points should be considered: (a) Indicated costs are estimates for the purpose of a first price indication; (b) It is only applicable to mills based on annually growing fibres such as bagasse, rice straw, cereal straw, reeds, bamboo and grass; (c) The indicated investment costs generally include f.o.b. equipment and spare parts, engineering services, ocean freight and transport cost, c.i.f. site, erection, commissioning and start-up, personnel training, civil construction; (d) Not included in the total are cost items such as land, contingencies, working capital and insurance; (e) Prices are based on cash payment for equipment and spare parts. The economic viability of small pulp and paper mills In itself, large-size does not mean that pulp and paper mills are more economical. There is, in fact, no general rule that determines minimum economic size. There are cases where even a 20-t/d pulp and paper mill, after a certain period of initial operation, has achieved or exceeded its rated production and one mill has since made excellent profits. Another has been so profitable that its expansion to 60 t/d was financed by the mill itself without loans from banks or other sources. It follows that economic viability must always be studied in connection with specific cases. There are, however, special conditions that prevail in many developing countries and which are more or less generally applicable. (a) With the capital outlay, raw materials are one of the most important cost factors. When they are agricultural residues such as rice straw or cereal straw, the price depends mainly on labour cost, which in developing countries is usually low. Another factor is transport cost, which can be kept low for small mills since transport is only over short distances; 12H Bagasse Ola Pith Moist depithing ' ' Olb 30 4 Fuel Handling and Package Storage steam boiler • ' Electricity 32/34 02 (purchased) Electrical Wet depithing equipment 03/04 Caustic soda Raw water Digester and blow tank Caustic si ' ' 15a 05 36 Caustic soda Washing plant Effluent disposal dissolving station 15b 37 06 Hypochlorite Distribution Screening plant preparation plant piping 4 L Ca Listic soda Hypo chlorite 07 J 15c 38 Air compressor Bleaching plant Chlorine storage Chlorine station i PAPE F1 MILL Chlorine i 20 Purcha sed pulp 41 Stock Laboratory preparation i ' 42 21 General plant Paper mill equipment ' 22 Paper finishing ¿ Paper Figure I. Flow chart for the departments of an integrated small pulp and paper mill (capacity 20-70 t/d). 129 InvMtmant colt par t/d 30 40 60 Mill capacity (t/d) Figure D. Budget prices for small integrated pulp and paper nrilis (raw material basis: non-wood plant fibres). IM) (b) Labour cost is another influential factor, and offers considerable advantages to developing countries. Compared to medium- or large-sized mills a small and simple pulp and paper mill requires only a small number of well-trained and skilled operators, the costs for whom do not count in the general calculation. Overall mill management is also easier to handle; (c) In comparison to a large one, a small pulp and paper mill usually does not require expensive facilities for pollution-control measures. On the contrary there are many small soda-based mills, especially in Asia, which neither have nor require any mill-effluent treatment plant. The black liquor from these mills is often released to the paddy fields, where it serves for irrigation and is also welcome as fertilizer. The positive effect of soda black liquor from straw mills as fertilizer for rice plantations has been confirmed in several studies. Since their volume is small, the paper mill and bleaching plant effluents can be released to the river in most cases with no special treatment. The advantages gained from lower raw material and investment costs for auxiliaries can, for a small pulp and paper mill, easily compensate for the higher expenses for non-recovered cooking chemicals, the purchase of power and, possibly, a somewhat higher specific investment per tonne of production. The privileges granted by Governments are a great help for pulp and paper mills in developing countries in facilitating the establishment of basic industries These privileges consist mainly of: (a) Duty-free import of machinery and equipment; (b) Tax exemptions to the mill for the first few years of operations; (c) Special duties on imports competitive with locally produced paper products. f K If governmental protection can be applied, it is generally easy to demonstrate the financial viability of integrated pulp and paper mills with capacities as low as 30 t/d. The feasibility of chemical recovery While small-scale mills should be designed as simply as possible with the minimum of service departments, the chemical losses are a considerable cost factor. In addition, regulations concerning water pollution can necessitate reducing the chemical content of the waste water. The investment cost of a conventional recovery system for small-scale mills is so high that a feasible operation is no longer possible. Normally, chemical-recovery systems are designed for maximum efficiency which, today, is in the range of over 90 per cent. Further increases in efficiency are almost impossible. The recovery system suggested for small-scale mills will have an efficiency only of 75 per cent; that is, at least 75 per cent of the chemicals necessary in the digester house will be recovered and transferred back to the process, and only 20 to 25 per cent will have to be as make-up. The cost for cooking chemicals is thus reduced to one quarter of their original value. For a 40-t/d plant with rice straw as the basic raw material, for example, the annual consumption of NaOH IM will be approximately 4,400 t. This amounts to approximately $1 million depending on the country where the mill is located, By using a chemical recovery system, $200,000 to $250,000 must be spent on chemicals annually. The investment cost for a plant of this size is in the range of $3.5 to $4 million. Assuming that the higher manpower requirement as well as the cost for power and water will be borne by the considerable smaller load on the waste-water treatment, one can expect that the chemical recovery unit will be amortized within about five years. A further reason for considering the installation of a chemical recovery system is to lessen the load on the waste-water treatment plant. In the above example, without a recovery plant, approximately 52 t/d of organic matter would go into the river. With a recovery plant, only 14 t/d would be lost which means a reduction to 27 per cent. From this it can be clearly seen that the installation of a chemical-recovery system is feasible in almost every case. However, it means a 20 per cent higher equipment cost for the pulp mill. This may, on the other hand, considerably improve the total efficiency and the cost per tonne of pulp. The main task is to design a simple chemical-recovery system for small- scale mills. The system is divided into three sections: (a) Evaporation. The evaporation rate of the black liquor is not as high as it would be with conventional plants. Instead of 55 to 60 per cent dry substance, the black liquor is evaporated to about 35 to 37 per cent dry substance. This has several advantages. The steam consumption is lower, and it is fully covered by the waste-heat boiler. The danger of scaling is considerably lower. Small-scale mills generally use annual plants as raw materials. Their higher silica content leads to problems, especially in the evaporation units. A system with a low dry content of, for example, only 35 per cent, however, needs no special precautions concerning scaling. Mild steel can be used almost throughout, and this influences the price of the plant positively; (b) Liquor burning. The black liquor will be burnt in a rotary kiln. The burning temperature is low and the plant is operated with high excess air. This has the advantage that the rise in viscosity resulting from silica content can be overlooked. (In conventional units, the rise in viscosity for silica-containing black liquors sometimes leads to insurmountable difficulties or necessitates a supporting flame.) The burnt ash is not molten, so that chemical attack on the refractory brick lining in the kiln is minimal. Furthermore, owing to the high volume of waste gases and their low temperature, there are no radiant heating surfaces. The thermal load of the waste-heat boiler is thus reduced. The waste gases that are cooled in the waste-heat boiler are utilized in the Venturi evaporator to concentrate the liquor from the evaporation plant. The waste gases are simultaneously washed and cleaned. The waste-heat boiler produces sufficient steam for soot-blowing and for the evaporation plant. There still should be a small surplus that could be used in the digester house. The ash falling from the rotary kiln is dissolved, and the green liquor is pumped to the recausticizing plant. (c) Recausticizing. The recausticizing unit is similar to that in conventional plants. Clarification by sedimentation should not be used because silica- ¡32 containing liquors are normally slow to settle. Green liquor and white liquors are therefore clanfied ,n drum filters. The re-use of the lime mud is not foreseen ÄTdÄS' ava"able loca"y at reasonable pr,ces'and "me mud can As a whole, the chemical recovery system is relatively simple and can be operated with relatively few workers. Universal pulping E. S. Prior* This paper describes a new process system designed around a small, simple, low-cost installation, very fast and flexible, operated with average expertise, producing low pollution levels and capable of using all practical sources of fibrous material to produce paper-making fibre. The system is basically acidic in its activation on the binding materials of fibrous structures and in attack on the cellulose components and, as shown, it appears that its strength characteristics are in kappa range 20 to 30 and can be roughly equated to sulphite pulps, kappa numbers well under 30 are usual in obtaining full defibration or the usual recognized state of a full chemical pulp from resinous woods. The correct defibrator and application should permit higher kappa numbers, yields and strength levels for board pulps. Pressure is not necessary; pulping can be accomplished in practically the same time or even more quickly with a non-pressure system. This affords the possibility of unique and relatively inexpensive installation designs, and it is easy to envisage economic production units varying from 15 to 100 t/d, well adapted to processing agricultural residues or small wood reserves. Preliminary trials have shown that straw cooked by this method, utilizing chemical concentrations of only 0.15 per cent, can produce an acceptable animal-feed supplement and extender. Trials leading to the commercial production of feed and paper pulp in this manner are expected to be initiated shortly in an existing nutrition plant utilizing wheat straw in the United Kingdom. The non-pressure equipment involved comes under the heading of light machinery and is well within the capabilities of developing countries to design and produce on a very economic scale. Although most experimental work has been done with flaked wood, trials with crushed chips indicate that existing chippers could be utilized. The black liquor derived from the process approximates a pH of 8.5 at the end of the delignification stage and is of a slightly sweet odour and practically tasteless. The lignin fraction can be precipitated out in a filterable flocculant by acidification to pH 6.0-6.5, preferably with alum. Both the whole black liquor and the decanted clear liquor from the precipitated form have been extensively tested, both on a single cook and on a sample in which the black liquor was recycled seven times. The liquor was found to be compatible in the processing of ordinary sewage in several ratios without disturbing normal practice, in which one part black liquor to three parts urban water provided the ideal combination. »Technical Director, Korrutek AG in Switzerland, Sunningdale, West Sussex, United Kingdom of Great Britain and Northern Ireland. /.?.? ÌU Comparative BOD5-COD and permanganate requirement are low Th, mmËËêmimproved strength properties. Additions have been mid up to 1 ne i m 1 cookmg straw has been found to be readily bleachable with peroxide E"S«^:;,r;;„T;:x" •d """" ""w,h "'= *- *w » Analysis of the black liquor shows a very low percentage of nh.n ,1 TK structures to the soil intact could be reduced turning fibrous he SSibiiity f Sma11 eCOn0mic |ahJ P° ° ' Potion units offers a variety of local mva A prospective fibrous resource for pulp and paper in Indonesia - alang-alang (Imperata cylindrica) R. Joedodibroto' INTRODUCTION Indonesia imports most of its paper needs. Its tropical forests, which cove M ner rent Of to land area of 190 million hectares (ha) are being exploited for UnTe b" are no, ye. utilized as fibrous resources for pulp and paper m—üreaThe reasons are the heterogeneity of -picaMoresls ac, of infrastructure the high capital investment needed and the advanced tccnnoiogy eS or pulping mixed tropical woods. Although both laboratory and p,l nil studies of the pulping of tropical woods from Kalimantan showed ptnis^reluto, the .ÍULfof a pulp and paper mil, based on ,hem stil. needs ,urt n rr^hirgrrht been USed, «*,«r * - **< in Indonesia ince 192. Grasses are easier to pulp than wood and give good 11 drwhen P "perly cooked. They are relatively richer in carbohydrates and ha e a lowef Ug^in content than wood. The processing of grasses for paper p u^t,:: can8.herefore be carried ou, with less energy anchemicals. ,n smaller mills and with the employment of more unskilled labour. THE CHARACTERISTICS OF ALANG-ALANG The erass Imperala cylindrica grows in many tropical and semitropical areas It if known as lalang in Malaysia, cogon in the Philippines,/«* ,n Sn Lanka cór^in Vie, Nam, ya-ka in Laos and Thailand, und lalang or anting—n'has been paid to this grass over the las, few years because of thf serious and increasing economic problem i, represents ,„ large ÏeasoMndonesia. In Indonesia, alang-alang occupies a. leas, 1Í.million ha of S with an annual increase of 150,000 ha. The grass is regarded as a noxious weed s"nce it frequently appears in cultivated plots and plantations and usually suppresses or even supersedes the growth of the main crop. Research Division of Ihe Cellulose Research lnslilule, Bandung. Indonesia. 'Head of ISñ However, alang-alang can also be useful as ground cover, preventing soil erosion and consolidating dykes and dams. The leaves serve as thatching and the young leaves, which appear after burning or slashing the plant, make good fodder. THE SITUATION IN INDONESIA The labour force in Indonesia is expected to increase to nearly 60 million in 1980 and to over 80 million by 1990. Without vast and successful efforts in education and training, a large proportion will remain at a low level of education and skill. However, large paper mills based on wood require sophisticated manpower, which will continue to be scarce for a number of years. On the other hand, the availability of alang-alang could provide various alternatives in the intermediate stages of the development of the paper industry in Indonesia because small mills based on grass are simpler, usually require chemical treatment and could absorb more unskilled labour. The uneven geographical distribution of the population in Indonesia is another important factor. Migration to areas outside Java has been intensified in recent years in order to enlarge job opportunities and food production as well as stimulate regional development. The soils outside Java are, however, on the average less fertile and less suitable to the current pattern of food production, where rice is dominant. Some 16 million ha of these soils are covered by alang-alang, and effective and ecologically acceptable methods for its elimination are not yet clearly established. If alang-alang could be used as a fibrous source for paper, it could possibly be utilized as an integral part of migration projects. THE PULPING AND PAPER-MAKING PROPERTIES OF ALANG-ALANG The alang-alang samples used for the study were obtained from the Institute of Tropical Biology, Bogor, and consisted primarily of leaf blades and sheaths, which were, respectively, 95 cm and 28 cm in length. Tappi standard methods were used throughout the investigations. Microscopic observations showed the average fibre length to be only 0.94 mm. Even though the fibres were short, they were slender, which is an advantage from the paper-making point of view. The chemical composition of alang-alang was found to differ from that of rice straw in that the ash content was markedly lower and the lignin content somewhat higher. Hot-water solubility was lower, indicating that the cell walls were not as easily accessible as with rice straw. It is safe to say that alang-alang would not be as easy to pulp as rice straw. The alang-alang sample used for pulping was prepared by cutting the grass into 3 to 4 cm lengths. Part of the sample was then pre-treated in the wet state by putting it through a disk refiner to remove some of the parenchymatous cells found in the leafy material; 11.6 per cent of the material was removed. When IM the same treatment was applied to rice straw, the amount removed was 16.3 per cent. Pre-treated as well as untreated samples were then pulped with sodium hydroxide as the pulping chemical. The pulping experiments were divided into four groups, based on the maximum temperature used. 1. Conventional soda pulping at 1 35°C maximum temperature was carried out at various levels of alkalinity in order to assess the quality of pulp suitable for bleaching. Yields of pulps of untreated alang-alang were lower and their kappa numbers were higher compared with the pre-treated alang-alang. The yields of rice-straw pulps, on the other hand, were higher and their kappa numbers evidently lower. Some samples were bleached by the three-stage chlorine/alkaline extraction/hypochlorite (CEH) bleaching process. A bleachable pulp is obtained at an alkali charge of at least 1 2 per cent. The brightness of the unbleached alang-alang pulps were around 40 per cent General Electric brightness (G. E.), whereas the rice-straw pulps cooked at similar cooking conditions gave pulps of 50 per cent G. E. After bleaching, a brightness around 80 per cent G. E. was acquired. When comparing the strength development of pulps from untreated and pre-treated alang-alang samples with that of rice straw, it was obvious that at all alkali changes, rice straw pulp strength properties were inferior to those of alang-alang pulp. The pulp of pre-treated alang-alang obtained at a low alkali charge were evidently higher in strength than that of the untreated sample. With an increasing alkali charge, this difference was not as evident. When bleached, strength properties were greatly improved at all freeness levels. 2. Hot soda pulping at 100°C maximum temperature was carried out at the same alkali charge as the conventional pulping process. To obtain bleachable pulps, a longer retention time at maximum temperature was applied. Instead of two hours the cooking time at maximum temperature was doubled. At 12 and 14 per cent alkali charge the yields obtained were close to 50 per cent, and the kappa numbers between 35 and 40, higher than during the conventional cook. Untreated alang-alang gave both lower and higher kappa numbers. The yields of the rice straw pulps were higher, as were their kappa numbers compared with conventional cooked pulps. The paper-making properties of the pulps show similar trends to those obtained by previous cooking. The strength properties were improved by bleaching. Compared to alang-alang, the rice-straw pulps had evidently lower strength properties. 3. Fractional pulping is a two-stage process. In the first stage 1 per cent alkali was used at a maximum temperature of 125°C for 10 minutes, and the pulping liquor was drained off. This treatment is intended to remove the hot water solubles and the 1 per cent alkali solubles, which are usually found in large amounts in grasses. The second stage used 170°C maximum temperature and IV2 hours retention time at two levels of alkali charges of 8 and 9 per cent. The yields obtained were between 40 to 45 per cent. The kappa numbers, however, were pronouncedly higher and the pulps were much darker. The unbleached brightness fell in the range of 30 per cent G. E., compared with 45 per cent G. E. of the hot-soda pulp. The pulps also had lower strength properties. However, alang-alang pulp was almost twice as strong as the rice-straw pulp. UH 4 Co,d soda ul in of m /1 " P P ë alang-alang was performed by soaking the grass in a 30 g/htre caustic soda solution at room temperature for two hours. To assure a better mixing and liquor movement at a low liquor-to-wood ratio similar to the previous processes, the rotary digesters were used during the soak. Defibrization was carried out in a Sproni Waldron laboratory disk refiner. The yield obtained tor alang-alang was 61 per cent and that for rice straw 70 per cent Here again deadly ler" "• *" ^^ ^ "" tíren*h • • CONCLUSION The experiments showed that alang-alang responded favourably to the various pulping conditions that could be used as the basis of the choice of technology A wide range of paper and board products of acceptable quality could be obtained from alang-alang, depending on the technology chosen This would give a flexibility of manufacture with regard to capital available, the degree of skills of the labour force, as well as the urgency of enlarging employment opportunities. * ë It is certainly worth while to consider plans for the utilization of alang-alane as an integral part of migration projects in Indonesia. However, further studies are necessary to identify the peculiarities of alang-alang as a fibrous resource and, most importantly, its behaviour during storage. Lime burning and alkaline pulping J. Leffler* The alkaline pulping process: general technical background When pulping wood or other fibre resources such as bagasse, straw, esparto etc. according to the soda or sulphate (kraft) pulping process, the cooking liquor consists of sodium hydroxide; in the kraft process, it also includes sodium sulphide. During the cooking about 50 per cent of the wood is dissolved by the cooking liquor and transformed together with the chemicals to a spent liquor, called "black" liquor. This black liquor is washed away from the fibres, concentrated by evaporation, and finally burnt in a recovery boiler. The concentration of dry solids in the black liquor from the washing is about 15 per cent and has to be increased to about 60 per cent before burning. The evaporation has to be done with attention to the successively changing properties of the liquor during its increasing consistency, when wide differences are revealed between black liquors depending on such factors as fibre raw materials, cooking liquors, and cooking yields. A choice of the evaporation principle and machinery must be made to minimize scaling deposits and foaming, and at the same time optimize investment, operation, and maintenance costs, with due consideration given to the intended necessary heat value of the evaporated black liquor to be used as fuel for the recovery boiler. Appropriate evaporation will be achieved by the proper choice and combination of falling and/or climbing film indirect evaporators, with or without pump forced circulation in tubes or plates. In certain cases, direct evaporators have also to be considered at the later stages. The recovery boiler operates like an oil-fired steam boiler. The design features of the boiler, and its operation, has also to be adapted to the black liquor properties in order to obtain an adequate operation, mainly to prohibit inside salt-cake ash deposits and thus guarantee steady operation efficiency. The proper design of evaporators and boilers is most important in case of high silica content or high viscosity resins in the black liquor. The organic compounds are converted to carbon dioxide and water. In the meantime a considerable amount of heat is given off as steam. The inorganic sodium components are recovered mainly as a smelt of sodium carbonate, which is dissolved in a water solution, called weak liquor, thus forming green liquor. •Technical Director, Swedforest Consulting AB, Solna, Sweden. This paper was prepared on behalf of the Swedish International Development Authority (SIDA). 139 140 The green liquor has to be transformed to active cooking alkali-sodium hydroxide-which is done by adding burnt lime to it, using the recausticizing reaction: NaaCOa + CaO + H2O —» 2 NaOH + CaCOs This reaction in necessary for closing the recovery circle and demands 200-250 kg burnt lime (CaO) per tonne of produced pulp. It is necessary to opt for the alkaline pulping process, not only from an economic point of view, with regard to the high value of the chemicals, but also because a black liquor disposal to the effluent could create severe pollution problems as a result of poisonous components and high biological oxygen demand (BOD). Waste of black liquor is only acceptable in case of small-scale pulp mills in combination with large effluent water recipients. The lime burning process Until about 25 years ago the demand for burnt lime for alkaline pulping recausticizing departments was normally satisfied by purchases from local lime kilns within the area or by own production at the pulp mill sites. This production was based on limestone shipped to and unloaded at the pulp mill harbour, as these older mills were normally situated by the sea or near a river, which facilitated the import of different chemicals and fuels, floating and sea storage of pulp wood and finally export of the pulp and paper products and by-products as turpentine and tall oil. The limestone was burnt in vertical shaft kilns masoned by bricks and fired with coal, wood or oil. The lime burning reaction is: CaC03 + heat > CaO + CO2 The by-product from the recausticizing process-lime sludge (CaC03)-is separated as a deposit from the reaction tanks, washed clean from residual chemicals and then wasted. The disposal of the lime sludge is arranged in different ways according to the local conditions: in tips, old sand quarries left from the construction of the mills or delimited areas of certain bays. In developed countries, disposal of lime sludge gradually became more difficult. The increasing size of pulp mills meant increasing volumes of lime sludge. At the same time the cost of unskilled labour was increasing, while petroleum fuel was becoming cheaper. For these reasons, limestone shaft kilns have been successively replaced by rotary kilns that dry and rebum the lime sludge, which is chemically the same as limestone (CaCOs). The first installation of this type was in Skutskär, Sweden. The fact that it was later shut down indicates that lime sludge reburning-already invented in the beginning of this century-has had to face many technical and economic difficulties. Only in recent years has it found its proper function in alkaline pulp mills as a normally more appropriate method of burnt lime production than shaft kilns. The method still has considerable drawbacks in certain applications. The main world production of burnt lime based on limestone is found 141 within other industries, where lime sludge is not available. It is now equally well established both with shaft kilns and rotary kilns. The choice of kiln type in these applications depends on such factors as capacity, investment, operation and maintenance costs, quality of raw materials, final products etc. Each has to be evaluated from industry to industry and case to case. The description of appropriate choices is outside the scope of this paper as far as other industries are concerned, but in certain special situations limestone burning in rotary kilns could also be an alternative to shaft kilns in the alkaline pulping. One example is if the kiln has to deliver burnt lime not only to the pulp mill but also to other industries within the area. It must then have a much higher capacity than the pulp mill demand. As a result the total economic evaluation may be in favour of a rotary kiln. Another example is an alkaline pulp mill planned to start up with limestone burning but later to switch to lime sludge reburning. In this case a rotary lime kiln will be mainly designed for reburning from the beginning and special arrangements must be made to permit small-size limestone burning during the first period until the sludge reburning starts up. Even with the lime sludge reburning some 5 to 10 per cent extra fresh limestone or burnt lime, primarily for making up normal losses, but also to keep up the quality of the burnt lime from the process point of view and to avoid disturbances in the pulp mill coming from lime sludge impurities such as silica, are needed. Case study: the Bai Bang Sulphate Pulp Mill in Viet Nam (a) General description This mill, a mutual Vietnamese-Swedish investment, will start up in the early 1980s and produce some 50,000 t/a of bleached and converted paper products according to the alkaline kraft process. The demand for burnt lime will be 50-75 t/d. The mill site is situated in the Viet Tri province of Viet Nam, which is scheduled for widespread future industrialization. Transport connections with the mill will be by railway and a river harbour. Raw material will be mainly bamboo in the beginning, but tropical hardwoods will also be used. The bamboo will be floated to the local harbour, and later chipped in the mill, including washing the river mud from the bamboo stems and chips as cleanly as possible. The pulp mill will be conventional, but appropriate to the local situation, and consist of: Batch digesters Filter washers Rotary screens Filter bleaching plant Climbing film evaporators with black liquor oxidation 142 Recovery boiler with cascade evaporators Tank recausticizing plant (b) The choice of production method for lime burning As the lime burning process is a peripheral activity of the total operation of W.lhin 10-15 years, bamboo will be replaced by pine from plantations and space has been reserved in the mill layout for the installation of arSTi n for lime sludge reburn.ng, should the investment for such a unit be agreedupon t^\rZ^The decston w,, dependgCneral on demand curren, Íninvestment V'e' • calculations,for to«h "-' and «-• wiuTo »" A rotary kiln installation could also occasionally be considered in onnect.on w„h a pulp mill, where burning of limestone will be later replaced b lime sludge reburn ne As this mnM K« in i c icpiaceu oy (c) Further reasons for the choice of installation The Sh ir Sta,lation in the Bai B nl,nt tf ^ ! •g PulP mill in Viet Nam, or similar plants m other developing countries, whose main purposes are to supply Traft M.-ì pulp mills, will also have the opportunity of satisfying other demands for burnt lime outside the pulp mills, when mill demands or the capacities of the kilns permit. The kiln can also be operated independently of the pulp mill demand; always at the same load for other customers. This facilitates an effective operation. Finally, the lime sludge not recovered may be valuable for soil preparation on acidic grounds. (d) Specific prerequisites As there are a number of suppliers of shaft lime kilns in many countries, a variety of alternatives needs to be studied. Considerations must take such factors into account as: Restriction on chemical and physical properties of the limestone Type of fuel and method of firing Manpower demand, quantity and quality Investment and operation costs Demand of utilities such as power, steam etc. and their costs Degree of instrumentation Quality and quality flexibility of the end product Possible demand of parallel-produced carbon dioxide Local industrial infrastructure Local experience Cost and consumption estimates for different shaft and rotary kilns (a) Investment costs The total investment cost for installation of a lime kiln naturally depends on such factors as country of manufacture and erection, transport and complexity of design. Based on current figures from the engineering department of a Japanese company, one of the largest shaft and rotary kiln manufacturers and users in the world, reliable installation costs are presented in tables 1 and 2. TABLE 1. INSTALLATION COST PER UNIT CAPACITY Capacity (t/d) 75 150 250 400 600 < 800 Shaft kiln ($) 28 900 22 400 18800 19 500" 16 800a Rotary kiln ($) - 26 400 21900 18 400 15 800 14 5(H) "Two kilns. TABLE 2. TOTAL INSTALLATION COSTS Capacity (t/d) 75 150 250 400 600 < 800 Shaft kiln (1,(KM)$) 2 170 3 350 4 710 7 810a 10 100a Rotary kiln (1,000$) -3 950 5 470 7 370 9 470 11580 a Two kilns. 144 (b) Heat consumption The figures in table 3 are based on Japanese experience. TABLE 3. HEAT CONSUMPTION Capacity (t/d) 75 150 250 400 600 < 800 Shaft kiln (k/cal/kg) 1 100 1 000 950 975 925 Rotary kiln (k/cal/kg) 1 700 1 600 1 500 1 400 1 350 | 300 (In case of lime sludge reburning, the heat consumption is 2,000 kcal/kg or more.) The heat is consumed for decomposition of the limestone and lost as exhaust heat, radiation heat and with the product according to the example in table 4. TABLE 4. HEAT BALANCE .SHAFT KILN Per cent Heal kcal/kg of total Decomposition 750 75 Exhaust 140 14 Radiation 100 10 In product 10 1 Total 1 000 100 Table 5 shows that rotary kilns are more heat consuming than shaft kilns. TABLE 5. HEAT BALANCE, ROTARY KILN (WITH PREHEATER) Per cent Heat kcal/kg of total Decomposition 750 54 Exhaust 410 29 Radiation 225 16 In product 15 1 Total 1400 100 (c) Electricity consumption The consumption of electricity is 40-45 kWh/t for the shaft kiln and 35-45 kWh/t for the rotary kiln. These figures do not include any crushing and screening of limestone or burnt lime. M.i (d) Steam consumption The consumption of steam for heavy fuel oil heating and atomizing is 50-100 kg/t. (e) Maintenance costs These costs may vary depending on operational and other site specific conditions (see table 6). As a rough estimate, repair costs a. e 15-20 per cent higher for rotary kilns. The difference comes mainly from the refractory costs. TABLE 6. MAINTENANCE COSTS (Dollars per tonne) Shaft Rotary Item kiln kiln Refractory 0.34 0.47 Others 0.54 0.56 Total 0.88 1.03 As a total average in both cases 1 $/t could be used. It should be pointed out that the shut-down period for repair of a shaft kiln refractory takes several weeks, including 3 to 7 days starting time, but only one week for a rotary kiln. This has to be considered when deciding the storage capacity of burnt lime, it no alternative supplier is available during the shut-down periods, and the demand from the pulp mill or consumer is constant. (f) Labour costs The number of operators required for operation of both types of kilns is almost the same, but could be much higher for a shaft kiln if this is designed to be operated with a minimum of transport facilities. (g) Plant space A rotary kiln plant needs about twice as much space as a shaft kiln. 14h Annex I SELECTED DOCUMENTATION PUBLISHED OR COMPILED BY UNIDO RELATING TO THE SUBJECT Information sources on the pulp and paper industry. UNIDO guides to information sour- ces no. 11. December 1974. 92 p. (ID/121 ) Environmental aspects of the pulp and paper industry. Prepared by C. Ccjcr. 1975. 173 p. diagrams, graphs, tables. (UNIDO/ITD. 349) Forest industry policy and choice of appropriate technology. Paper prepared by R H.Carlsson and others for the International Forum on Appropriate Indus ria Technology, New Delhi and Anand, India, 1978. 1978. 164 p. (ID/WG 282/22) Technologies from developing countries. Development and transfer ot technology senes no. 7. December 1978. 35 p. (ID/208) Pine needles, p. 3. Papers issued for the Expert Group Meeting on Pulp and Paper, Vienna, 13-17 September ¡971 ID/111 Pulp and paper in developing countries. Report of an Expert Group Meeting. 67 p. ID/WG. 102/3 How to build a low-cost paper mill in developing countries. 16 p. table. K. Zappert ID/WG. 102/4 Newsprint from bagasse: past and possible future action. 30 p. tables, map, diagram. E. Villavicencio ID/WG. 102/5 A practical approach to waste paper utilization in developing countries. 13 p. H. Herman ID/WG. 102/6 Prospects for bagasse newsprint in India. 17 p. S. Guha ID/WG. 102/7 Use of mixed tropical hardwoods for production of pulp and paper in India. 21 p. D. Ganguly ID/WG. 102/8 How to raise the level of efficiency in the pulp and paper mills of developing countries. 47 p. tables, illus. T. Jeyasingam ID/WG. 102/9 Collection and utilization of waste paper in Ceylon. 51 p. tables, diagram, floor plan, map. T. Jeyasingam ID/WG. 102/10 Practical experiences in the use of mixed tropical hardwoods for production of pulp and paper. 26 p. tables A. Panda ID/WG. 102/11 Experiments on the Indonesian rubberwood as raw material for pulp and paper. 46 p. tables, illus. Alaudin, Soeprapti K, Moehji Rn, Sri Margono, Hendayani, TA, Soetrisno, Kahar 147 ID/WG.102/12 Achieving a high level of efficiency in the pulp and paper mills of developing countries. 37 p. E. Crane ID/WG.102/13 The special problems involved in developing, building and operating pulp and paper mills in developing countries. 31 p. J. Atchison ID/WG. 102/14 Trends in pulping of mixed tropical hardwoods. 19 p. L. Bratt ID/WG. 102/15 Practical experience in the use of rubberwood for the production of pulp and paper. 37 p. tables. D. Stacey ID/WG. 102/16 How to build a low cost pulp and paper mill in developing countries. 50 p. diagrams, tables, graph. P. Chaudhuri ID/WG. 102/17 Practical experience in the use of mixed tropical hardwoods for the production of pulp and paper. 39 p. J. Grant ID/WG.102/18 Newsprint from bagasse. 33 p. tables. Y. Fouad ID/WG. 102/19 How to raise the level of efficiency in pulp and paper mills in developing Rev. 1 countries. 21 p. map. O. Dalley and A. Holloway ID/WG. 102/20 Dissolving pulp from mangrove and para rubberwood. 42 p. tables, graphs. T. Kayama, M. Nakamura and A. Nagoshi ID/WG. 102/21 Practical experiences on pulping mixed tropical hardwoods. 48 p. tables, diagrams, maps. p. Cardenas ID/WG. 102/22 The utilization of waste paper in the paper industries of developing countries. 45 p. tables, graph, map. F. Doane ID/WG. 102/23 How to build a low-cost paper mill in developing countries. 59 p. illus., diagrams. A. Binder ID/WG. 102/24 Manufacture of dissolving pulp from exotic raw materials. 40 p. tables. Y. Fahmy ID/WG. 102/25 Formulation of a set of rules for a systematic repair and maintenance service in the pulp and paper industries of developing countries. 38 p. statistics, diagrams. S. McGilvray ID/WG.102/26 Manufacture of dissolving pulps from exotic raw materials. 23 p. tables. J. Nowakowski ID/WG. 102/27 Practical experiences in the use of mixed tropical hardwoods for the production of pulp and paper. 8 p. tables. B. Gupta ID/WG. 102/28 Retrospects and prospects of newsprint from bagasse. 32 p. tables. S. Krishnaswamy ID/WG. 102/29 Bagasse newsprint. 43 p. graphs, diagrams, tables. D. Cusi and P. Jolley ID/WG. 102/30 How to build a low-cost pulp mill in developing countries. 21 p. graphs, tables. E. Van den Ent, V. Roos and E. Westerberg 148 ID/WG. 102/31 How to raise the level of efficiency of the pulp and paper mills in developing countries. 12 p. V. Podder ID/WG. 102/33 Practical experiences in the use of mixed tropical hardwood for the man- ufacture of pulp and paper. 12 p. table. B. Mayer Papers issued for the International Forum on Appropriate Industrial Technology New Delhi and Anand, India, 20-30 November 1978 ID/WG.282/21 Paper cardboard, corrugated cardboard, polyethylene shrink and stretch film for better packaging. 57 p. S. Mulitsch di Palmenberg ID/WG.282/47 Choice of appropriate packaging technology. 40 p. M. R. Subramanian ID/WG.282/64 Packaging: an integrated part of economic development in developing countries. 21 p. h 6 Z. Zackiewicz ID/WG.282/74 Technologies for the production of steel and aluminium packaging. W. P. Fomerod ID/WG.282/65 Technologies from developing countries. 251 p. Pulping of rice straw pp. 152-154. diagram. Pulp making from rice straw, pp 155-157' diagram. Use of agathis loratifolia for paper pulp, p. 158. Dacridium SPP or pulpwood, p. 159. Use of rubber tree for pulp and paper, p. 161. Paper pulp moulding system, pp. 162-163. Technical information compiled by the Industrial Inquiry Service (US) and the Industrial and Technological Information Bank (I NT IB) Copies of these compilations are available to requestors from developing countries only 1 he reference number must be quoted. Fireproofing of paper and cardboard. (IIS file no. 8352) Kenaf for paper production. (IIS file no. 8076) Newsprint. (IIS file no. x5493) Paper from abaca (Manila hemp). (IIS file no. x3710) Paper processing. (IIS file no. x3392) Paper production from bagasse pulp. (IIS file no. x2942-45) Pulp and paper. (IIS file no. 6746) Pulp and paper from bagasse. (IIS file no. 8380A) Pulp from hemp fibre. (IIS file no. 6341) Starch adhesives. (IIS file no. 8143) Water resistant emery paper. (IIS file no. 5096) 149 Annex il WORKING GROUP PARTICIPANTS AND OBSERVERS Participants A. D. Adhikari, Managing Director, Ashok Paper Mills Limited, Jogighopa, Assam. In- dia. D. Attwood, Director, The Research Association tor the Paper and Board. Printing and Packing Industries, Leatherhead, Surrey, United Kingdom. L. N. Chowdhary, Deputy Works Manager, Star Paper Mills Ltd., Saharanpur, Utter Pradesh, India. M. A. H. El Ebiary, Chairman, Rakta Pulp and Paper Mill, General Company for Paper Industry, Alexandria, Egypt. (Chairman of the Working Group) L. Ehling, Project Engineer, Babcock Krauss-Maffei Industry, Munich, Federal Republic of Germany. J. O. Escolano, Science Research Assistant Chief, Forest Products Research and Indu- stries Development Commission, Laguna, Philippines. P. M. L. Gentil, Groupe Européen de la Cellulose, Paris, France. S. R. D. Guha, Director, Forest Products Research, Forest Research Institute, New Del- hi, India. A. G. M. Hussain, Director General, State Company for Pulp and Paper Industries. Bas- ran, Iraq. T. Jeyasingam, Consultant, Longview, Washington, United States of America. R. Joedodibroto, Head of Research Division, Cellulose Research Institute, Bandung, In- donesia. J. A. V. Leffler, Technical Director, Swedforest Consulting AB, Solna, Sweden. L. O. I. Lindblad, Head of Section, Swedish International Development Authority. Stockholm, Sweden. V. L. Moorthy, Production Manager, Pan African Paper Mills (EA) Ltd., Webuyc, Ke- nya. N. K. Naithani, Principal, Institute of Paper Technology, Saharanpur, India. E. S. Prior, Technical Director of Korrutek AG, Zurich, Switzerland. A. W. Western, Chairman, Reed Engineering and Development Services Ltd.. London, United Kingdom. (Rapporteur of the Working Group) Z. Zaczkiewicz, Consultant, Warsaw, Poland. M. L. Zutshi, Chairman and Managing Director, Hindustan Paper Corporation, Calcutta. India. Observers P. B. Chaudhuri, Celpap Engineering, Norrkoping, Sweden. N. K. Saha, Ashok Paper Mills Ltd., Jogighopan, Assam, India. \ Printed in Austria 79-1562 - August 1979 - 1 (),()()() ID/232/3 • •