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WOOD PRODUCTION OF LIQUID OR GASEOUS FUELS1/ J. Zerbe Products Laboratory2/ Forest Service, US Department of Agriculture United States of America INTRODUCTION

Technology for making liquid or gaseous fuels from has been available for more than a century but it is limited. Liquid fuel technology has been limi­ ted to ethanol, and has been limited to the generation of low heating value or "producer" gas. (A history of ethanol discoveries and production and of devices is shown in tables 1 and 2 respectively).

Although liquefaction and gasification technologies are not new, their commercial application has not been convincingly successful. Usually, the only times these alternative sources of energy have been used were during national emergencies when fossil fuel supplies were severely restricted. But since the rapid rise of fossil. fuel coats during the last decade, fuels derived from , which have been only marginally competitive, may become more desirable.

History One of the first recorded manufacturers of suction-type gasifiers were Grossley Brothers Limited, Openshaw, Manchester England, at around the turn of the century. According to Mr E.R. Mellenger (9) 3/, this company built some 4,000 units to use cellulosic fuels. Mellenger also reports on a plant in McBride Bay, Canada, where two 12-million-British-thermal-unit-per-hour (Btu/h) producers (3.5 megawatts (MW) drove two 750 kilowatt (kW) Crossley-opposed engines. The units operated at McBride Bay until 1947, when they were sold to Tokapaci in Mexico, and were said to be powering a brickyard in 1977. R.S. Evans (5) states that a Crossley unit operated on the west coast of Vancouver Island, first at Nootka and then at Tahsis, between 1936 and 1955, gasifying ood and providing electric power to isolated . However, this gasifier may have been the same one mentioned by Mellenger. An article in The Timberman of November 1937 (3) describes a mill driven by at Port Tahsis, McBride Bay, Nootka Sound, on the west coast of Vancouver Island. According to the article, this was the first electrically operated in North America having a gas producer engine using woodwaste for fuel. The main electric power was supplied by a 750 kW generator directly connected to the Crossley-Premier gas producer engine. Since then many biomass-fueled gasifiers, mostly of European manufacture, have been installed and are still operating for stationary engines. Tables 3 and 4 list installations by Power-Gas Corporation and Duvant 4/.

Another European development was the Imbert generator by Mr Imbert of Alsace Lorraine during the First World War. Although the Imbert Company now manufactures gasifiers for stationary engines, it previously manufactured gasifiers for motor vehicle engines.

1/ This report was prepared for the seminar on reducing forest biomass losses in operations which was held in Moscow (USSR), 4-11 December, 1982. In view of its relevance, however, to the Bonn seminar on energy conservation and self-sufficiency in the sawmilling industry, it has also been included in these proceedings. 2/ Maintained in cooperation with the University of Wisconsin 3/ Underlined numbers in parentheses refer to literature cited at the end of this report 4/ Ets Duvant, founded in 1878, began industrial diesel engines in 1920 and at that time investigated the possibility of running them on producer gas made from organic wastes such as wood and grain. A renewed effort to market dual-fuel engines that run on 10 % and 90 % producer gas began in the mid 1970s. - 334 -

Table 1. Early discoveries and U.S. ethanol production from wood

Date Event 1819 Braconnot discovered that could be. dissolved in concen­ trated acid solutions and converted to sugar 1855 Wood was hydrolyzed with dilute acid in an autoclave 1898 Research and development work on wood hydrolysis in progress in the United States 1912-20 Two dilute acid hydrolysis plants in operation located at Georgetown, South Carolina, and Fullerton, Louisiana 1944 Springfield, Oregon, wood hydrolysis plant built. Capacity of 220 tons (200 t) of wood/day or 11,500 U.S. gal (43,600 L) of ethanol Bellingham, Washington, plant built at a sulfite pulpmill to convert spent sulfite liquor to 9,000 U.S. gal (34,000 L) of ethanol/day

Table 2. A history of producer gas devices (10) Date Event 1839 Bischof manufactured gas in a separate producer (Germany) 1861 Siemens' gas producer developed (Germany) 1878 Dawson's gas producer : A "true" suction producer that is, draft caused by intake stroke (England) 1889 "Mond" by-product process : or peat having a small amount of was gasified in conjunction with a by- product plant to make ammonium sulfate 1930s Activities of the Comité International Du Bois resulted in the development of advanced down draft units for automobile propulsion 1940s Second World War - re-emergence of mobile and stationary uses in Sweden, USSR, England, Canada, Germany, Denmark and Japan 1945 Readily available, cheap petroleum era results in abandonment of commercial production of gasifiers by the mid-1950s - 335 -

Table 3. Power-Gas Corporation producer gas plants (6)

Client and location Fuel Order date Ceylon Government Poisons Department, 1947 Colombo Henry Rogers Sons & B° Ltd., Brazil 1951 R. Butler Eng., Moreton in the March, Wood waste 1943 Glas., England Soanes Irmoas, Portugal Olive refuse 1945 East African Manaze, Bd., Kenya 1943 Administrator of St. Kitts sugar Electric Light Department, West Indies refuse 1947 Fabricas Triumpho, Portugal Wood blocks and chips 1948 Mahalakshi Sugar Mills B° Ltd., India 1948 Mozambique Industrial S/A, Portuguese East Africa Seed husks or wood 1951 Kafer et Zayat B° Ltd., Alexandria, Egypt Seed husks or wood 1946 E. Matarazzo & B°, Brazil 1934 Magadi Soda Works - Fertilizers and Chemicals, Kenya Wood logs 1934 Gravancore Ltd., India Wood logs 1943 Monapo, Mozambique Seed husks 1965-67

Table 4. Duvant units operating, under construction, or in negotiation (6)

Company Location Fuel Société Palmivoire Abidjan Coconut husk Electricity of Tahiti Papeete Coconut husk and shell Société des Moteurs Duvant Valenciennes, France Miscellaneous organic wastes Société Abile-Gal Abidjan Coffee shell Cemento Nacional Managua, Nicaragua Various organic wastes National Electrification Philippines Coconut shell Administration Manufacturers of coconut oil Philippines Coconut shell

Enuluf Société Rationale Nicaragua Bamboo waste Eléctricité - 336 - Figure 1. Gasifier under development at the Forest Products Laboratory during the Second World War (M 44745 F) - 337 -

The Imbert wood gas generator for automobiles and trucks was developed through private capital before the Second World War began. During the last few months of the war, Germany was forced to use the generator even though it was unreliable, started slow in cold weather and cut power by 25 %. Other companies manufacturing gasifiers for vehicles in Germany during the Second World War were Deutz, Stinnis A.G. in Mühlheim, and Daimler-Benz in Stuttgart.

In Sweden during the Second World War, some 90 % of that country's 75,000 vehicles were powered by gasifiers (6). In fact, a number of vehicle gasifiers were developed between the two World Wars, primarily as a result of the Comité International du Bois Propaganda Section of Vienna. One result was the Packer Gas Producer, used to power trucks as early as 1921. Another development was the Charco Gas Producer, used on about 50,000 automobiles fueled by either or anthracite. The U.S. Forest Products Laboratory also developed a gasifier during the Second World War (fig. 1).

Gasifiers to provide fuel for heating and lighting with biomass were developed even earlier. In 1878, Franklin B. Hough reported on the manufacture of illuminating gas from wood (7). However, wood gasification for heating and cooking gas, boiler fuel and kiln heating was abandoned in the decades prior to the 1973 oil embargo.

Wood for manufacturing charcoal has, of course, always been a viable alternative, and some charcoal manufacturing processes use by-product gas for process heat.

Liquid fuels The history of making liquid fuels from wood covers manufacture of or "wood alcohol" by and of ethanol or "grain alcohol" by hydrolysis and by direct fermentation of sulfite waste liquor.

Methanol : In the mid-1930s, about 50 by-product recovery plants existed in the hardwood distillation industry. By the mid-1960s, only six plants remained (2). The reason was changing economic conditions, including increasing costs for raw material, equipment and labour, and lack of adequate markets for methanol and acetic acid. The last hardwood distillation by-product recovery plant in the United States closed in 1969. Other countries that more recently produced signi­ ficant quantities of distillation products include Albania, Austria, Canada, Federal Republic of Germany and Sweden. There have been distillation operations likewise in Belgium, Chile, France, India, Japan, Mexico and the United Kingdom (2). Ethanol : (The following history of acid hydrolysis of wood to make ethanol is adapted from Forest Products Laboratory Report N° 2029 (8).) Braconnot dis­ covered in 1819 that cellulose could be dissolved in concentrated acid solutions and converted to sugar. Much research has been carried out since then in attempts to develop economically sound processes for making sugar from wood. A particularly active period occurred around the turn of the century, when research and develop­ ment work was in progress both in the United States and in Europe. Researchers M.F. Ewen and G.H. Tomlinson are credited with developing a dilute sulfuric acid process that was used successfully in two commercial plants during the First World War. One of the plants was located at Georgetown, South Carolina, and the other at Fullerton, Louisiana. The "American process", as this early hydrolysis method is now called, used a short reaction time in a rotary digester at a comparatively low temperature. As a result, the process depended almost entirely on the easily hydrolysable material for sugar production. A low wood-sugar yield of about 22 % resulted. The end product at both plants was ethyl alcohol, each plant producing over 5,000-proof gallons (19,000 litres (L) per day. The great demand for depleted timber holdings rapidly, causing a curtailment of the mill operations - 338 -

that furnished woodwaste to the hydrolysis plants. The shortage of raw material and low blackstrap molasses prices forced both plants to close soon after the First World War.

Wood hydrolysis received considerable attention in Europe between the two World Wars. From this era emerged two radically different processes that attained particular prominence in Germany during the Second World War. One process used 40 % hydrochloric acid at atmospheric pressure in expensive acid-resistant equip ment. High acid requirements made acid recycling imperative and contributed markedly to excessive plant costs. High product quality and high sugar yield, however, were claimed to offset the high capital investment and production costs.

The other process, commonly known as the Scholler process, used dilute sul­ furic acid and steam pressures up to 200 pounds per square inch (lb/in2) (1,380 KiloPascals (kPa)) to promote the hydrolysis reaction. It differed from the American process in that a stationary digester was used and many batches of acid Liquor were passed through the same charge. From 16 to 20 hours were required to complete the hydrolysis. Sugar yields of 70 to 77 % of the theoretical maximum were reported for the Scholler method.

In 1935, the Cliffs-Dow Chemical Company acquired the American rights to the Scholler process and conducted a pilot-plant evaluation of it at Marquette, Michigan. In 1943, at the request of the War Production Board, the U.S. Forest Products Laboratory began to re-examine dilute sulfuric acid hydrolysis, using the pilot-plant facilities of the Cliffs-Dow Chemical Company for initial inves­ tigations. With information acquired at this pilot plant along with Scholler specifications, a full-scale demonstration (modified Scholler process) wood- hydrolysis plant was designed and built at Springfield, Oregon. This was a rapid percolation process that became known as the Madison process. It is similar to the Scholler method of hydrolysis in that a dilute sulfuric acid solution is per­ colated through or in a stationary digester. It differs, how­ ever, in that, after an initial low-tempterature hydrolysis period, the acid solu­ tion is pumped in continuously at the top and hydrolysate is removed at the bottom with no interruption until the hydrolysis is completed,

Another ethanol technology is fermentation of the hexose sugars in coni­ ferous spent sulfite liquors. Sulfite pulpmills around the world have practised this technique for many years (11). Today one manufacturer in the United States uses this process (Georgia-Pacific Corporation in Bellingham, Washington). Others outside the United States are the Ontario Company in Thorold, Ontario, Canada, a plant in Attisholz, Switzerland, one in Tampere, Finland, and several in Sweden. Before the Second World War, the ethanol from Scandinavian sulfite mills was the basis of the Scandinavian synthetic chemicals industry.

Processes under development Gasification Since the 1973 oil embargo, a large effort has been mounted to improve technologies for alternative fuels from biomass in North America. Gasification of wood, in particular, has received much attention.

Efforts have been renewed to use wood gas to run internal combustion engines, especially for power generation. Unfortunately, the most publicized attempts in Alaska and Prince Edward Island, Canada, have been unsuccessful. The Alaska Village Electric Cooperative conducted efficiency and endurance testing of a gasifier-engine-generator. They hoped to provide a reliable and efficient source of energy for use in moderate-sized communities in rural Alaska, where the cost of transmission lines to tie into central power grids is prohibitive. The effort, however, was discontinued because the engines were damaged by in the fuel too frequently. - 339 -

Recently Pyrenco Inc. announced results of a 24-day test of a gasification system near Prosser, Washington. Output of the downdraft gasifier is 3 to 5 million Btu/h (880 to 1,470 kW) at a claimed 81 % conversion efficiency. Heat content of gas produced from wood and bark pellets is 157 Btu/cubic foot (ft3) (5,850 kiloJoules/cubic meter (kJ/m3)). Gas was fed to a diesel electric genera­ tor at a fuel mix of 90 % producer gas and 10 % diesel. The generator was rated at 175 kW and produced a maximum of 120 kW using the diesel/producer gas mix. Average output of the test was 104 kW. Teardown and inspection of the showed no abnormal wear or deposits.

In New Holland, Pennsylvania, Ed Zimmerman, President of E.Z. Manufacturing Company, has developed a gasification system that uses wood residues to produce gas for fuel, plus tar and charcoal. The system is applied onsite at the manu­ facturing plant and Zimmerman hopes to market it someday to the forest products industry. With a spark ignition engine, the system uses approximately 300 lb/h (136 kg/h) to produce 3.5 million Btu's (1,030kW), or enough to operate the manu­ facturing plant's 300-kW generator. The unit can also use chips and bark and green or hardwood sawdust.

In Scandinavia more emphasis is being placed on gasifiers for mobile appli­ cations. A tractor-mounted gasifier has been developed by the Finnish Research Institute of Engineering in Agriculture and . Existing designs were modified for testing on a 55-kW farm tractor. The engine lost only 20 % of its peak performance. It was also noted that the fuel for an ordinary diesel engine must be 20 % oil for ignition, while the remainder can be supplied in the form of gas from wood. The average fuel consumption during the test was 11.5 L/h on pure diesel oil and 2.3 L of oil/h plus 0.2 m3 of chips/h with the combination of fuels.

Other gasification efforts are aimed at providing fuel for direct heating applications. Energy Resources Co Inc., Cambridge, Massachusetts, aims to market plants to gasify wastes from and crops. They will be fluid-bed gasifiers assembled and ready for use. The generated gas may be used in existing steam boilers, kilns and dryers. Output of the plants is predicted at 10 to 200 million Btu/h (2,900 to 59,000 kW).

A 20-million-Btu/h (5,900 kW) wood gasification system has recently been installed at a brick manufacturing plant in North Carolina. The manufacturing process requires drying and preheating the brick with recycled heat, firing at 2,000° F (1,093° C) and cooling with air that is re-used in the drying and pre­ heating section. The brick company considered both gasification and direct firing of the readily available local supply of sawdust as options for reducing fuel costs. The direct-firing option was eliminated because of the relatively high capital and operating costs and because the unburned wood ash discoloured the brick. The selected gasification system will produce a 150-Btu/standard ft3 (5,590 kJ/m3) gas from the sawdust (30 % moisture content, wet basis).

The Georgia Institute of Technology Experiment Station is assessing the market for updated gasifiers in the textile industry. Applications include boiler retrofits for process steam and the substitution of wood gas for natural gas in direct-fired textile dryers. The survey is investigating the type and capacity of typical boiler and dryer systems, their yearly fuel usage and cost, and tech­ nical constraints on gasifier conversion such as space limitations and product contamination. The second objective of the programme is an experimental test project on the Georgia Tech campus. A pilot-plant gasifier, rated at approxima­ tely 1 million Btu/h (293 kW), was successfully started up in May 1980. This experimental gasifier is being used to dry and cure textiles to investigate any detrimental effects on fabrics and carpet from contaminants in the combusted wood gas. - 340 -

Energy Products of Idaho (EPI) is designing and constructing a large-scale commercially applicable gasification system in Sacramento, California, that will convert biomass fuels to energy. When completed in late 1982, the system will provide approximately 50 % of the energy required for heating and cooling over 4 million square feet (ft2) (371,600 square meters (m2)) of office space for the State of California in the downtown area and result in an annual savings of over $500,000. The State of California's $3.0 million project is termed one of the most significant alternative fuel projects ever undertaken by the State. The EPI's Fluid Gas gasification unit forms the basic energy cell for the conversion of biomass waste material to a low-heat-value combustible gas, which can then be ignited in an existing boiler to produce steam. The system will use biomass fuels such as woodwastes, trimmings, and agricultural by-products to be collected in and around Sacramento. In addition to the gasification unit, EPI will also design and construct the complete fuel receiving, screening and storage facilities, the modifications to the existing boiler to permit firing to low-heat-value gas fuels, and the off-gas emission control system. Through use of a multiclone, the particulates in the gas stream will be removed to the point where air returning to the atmosphere meets or exceeds all local air pollution standards. The Fluid Gas Energy Cell is an advanced development of EPI'S Fluid Flame Fluidized Bed Combustor, which has over 40 units currently in use in the United States, Canada and Japan. During the gasification process, the biomass materials are mixed with super-heated sand in the gasification chamber and allowed to burn at a controlled temperature and reaction time. The fluidized bed is operated at approximately 1,500° F (816° C) providing a high efficiency for conversion with a minimum amount of residue.

The largest wood gasifier in operation in North America now is the Omnifue1 Gasification's Systems unit installed at the Levesque mill at Hearst, Ontario, Canada in March 1961. It produces gas that is used directly in the mill to supply process heat. The 80-million-Btu/h (23,400 kW) gasifier uses about 7 tons/h (6.35 tonnes (t)/h) of woodchips, bark and sawdust to produce a 150-Btu/ft3 (5,590 kJ/m3) gas. Florida Power Corporation, the St. Petersburg, Florida, public utility, is looking closely at wood gasification for alternate power generation. A 25-million Btu/h (7,330 kW) wood gasifier was purchased from Allied Engineering, Orangeburg, South Carolina, and can use green composed of whole-tree chips, sawdust or wood shavings. When operating at full capacity, the gasifier uses 6,500 lb/h (2,950 kg/h) of wood at 50 % moisture content. The gasifier is a second-genera­ tion model of one previously installed at a hospital in Rome, Georgia.

Another possibility for using gas generated from wood is gas turbines. Since 1980, the Chrysler Corporation has seriously pursued development of the for passenger cars. Other companies that have worked on gas turbines include General Motors, Ford, Williams Research and Volkswagen. To date, none of these programmes has resulted in an automotive gas turbine engine that can be mass produced. The main drawbacks have been high manufacturing cost and low fuel economy.

Pyrolysis might be considered a special case of gasification where other solid and/or liquid products are generated in addition to gas. Total Energy systems Inc., Los Angeles, California, has installed a 60-ton/day (54 t/day waste processing module in Asheville, North Carolina. It is currently being used to run demonstration-scale pyrolysis tests on sawdust, woodwastes and woodchips. The plant aims to increase capacity to 200 to 300 tons/day (181 to 272 t/day) and to produce gaseous fuel for the Sayles Biltmore Bleacheries next door and charcoal for Kingsford Charcoal Co. located in Asheville. The process is based on a thermal unit that operates at temperatures between 900° and 1,100° F (482° and 593° C). Control is maintained over residence time and temperature as material - 341 - travels through the unit. This allows use of a heterogeneous feedstock to produce the same output. Combinations of , oil and gas can be produced, or the oil may be recycled to increase gas output.

Liquefaction Liquefaction processes under development include hydrolysis to ethanol, fermentation of pentoses to ethanol, conversion to methanol through synthesis gas, catalytic conversion (hydrogenation), and extraction of natural oils.

Commercial fermentation alcohol plants exist only in the Soviet Union but throughout the industrial world this technology has stimulated much research, planning and related activity including building and operation of pilot plants.

A modification of past technology that is being adapted to dilute acid hydrolysis processes, especially where hardwood feedstock is involved, is two- stage hydrolysis. A mild prehydrolysis is conducted to remove the hemicellu­ loses and convert them to simple sugars before the main hydrolysis converts cellulose to glucose. Hardwood are largely pentoses, which may yield valuable products. These include yeasts and animal feeds and in the past few years, basic research has shown how to ferment pentoses to ethanol, This is not close to commercialization now, but it does nonetheless show promise of being a significant breakthrough.

Other new techniques being researched are auto-hydrolysis, steam explosion or other pre-treatment, and enzyme hydrolysis. Auto-hydrolysis consists of catalyzing the hydrolysis reaction with organic acids that occur naturally within wood. Steam explosion occurs when wood is suddenly subjected to high steam pressure for short times before the pressure is abruptly released. The object of this treatment is to make cellulose more available for hydrolysis and thus render it more hydrolyzable. Other treatments, such as removal of with organic solvents or alkali, have the same objective. Enzyme hydrolysis uses natural organisms to promote cellulose saccharification. Potential conversion efficiencies for the cellulose-to-glucose transformation are higher than with dilute acid. However, it is generally agreed that dilute acid hydrolysis tech­ nology is best suited for application in commercial plants in the near term because of previous experience.

For some time Tampella, Tampere, Finland, has had a two-stage pilot hydro­ lysis process in operation. The first-stage hydrolysis can be either auto- hydrolysis at 190° C or hydrolysis with 0.5 % sulfuric acid at 140° C. With the higher temperature, more furfural is produced, and with the lower temperature more of the is converted to sugars. The second stage is operated at 190° to 200°C with 0.5 % sulfuric acid, Feedstock is fine chips or shavings. Material from the second stage is classified by size by blowing through a hydro- clone or cyclone. The coarse fraction is recycled from the blow cyclone back to the hydrolyzing vessel. Lignin is separated and pressed to a moisture content of 40 % for burning. It is anticipated that this process will soon be commercial. One plan would have the plant located at the centre of a circle of 100 km radius from which feedstock would be provided, The feed to the plant is anticipated to be 27 dry t of cull wood/h.

In Brazil, Coque e Alcool de Madeira (Coalbra), a Brazilian Government- owned company, has projected a wood-to-alcohol palnt a number of times during the past 5 years. It has been reported (1) that in 1982, Brazil signed an agreement with the USSR to build a $20 million, 30,000-L/day fuel alcohol plant in Uberlandia, Minas Gerais. Also, according to the news article, six Soviet- trained technicians will assist with the construction of the plant, which will use chips as its main feedstock. Each dry tonne of eucalyptus is said to be capable of producing 200 L of ethanol, 400 kg of lignin for , 40 to 50 - 342 - kg of animal feed, 6 kg of furfural and 10 kg of . Demonstration plant design will come from the Foundation for Industrial Technology, Rio de Janeiro, Brazil. This centre now runs a 3-t/day wood-to-ethanol pilot plant. The pilot plant is showing sugar conversions and ethanol yields in established ranges.

Also close to beginning construction at the time of writing (July 1982) is a 500,000 gallon/year (1,900 L/yr) wood-to-ethanol plant using New Zealand developed technology. Ultrasystems Inc. of Irvine, California, and the Bunyan Corp. of Dallas, Texas, are joint venture partners in the project. The plant site is near Norman, Arkansas, and close to two lumber mills that will provide sawdust, wood shavings and other waste products for feedstock. Bunyan has owner­ ship in the lumber mills and will arrange private financing, provide financial management services and market the ethanol, Ultrasystems, which has obtained the world-wide marketing rights to the process from the New Zealand Government, aims to build more plants in the 1- to 5-million gal/yr (3.8 to 19 million L/yr) range. Sites in the Pacific Northwest, mid-South and mid-Atlantic coastal regions, as well as overseas, are under consideration. Southern will be used as feedstock at the Norman plant, but research and development on hardwoods is planned for other plants expected to be built in the United States.

In Minnedosa, Manitoba, Canada, Canadian Mohawk Oil has a plant for making ethanol from . Plans are being made to build a second feedstock processing module for lignocellulosic conversion. The installation would use 50 t of aspen woodchips/day. Later, if the plant is successful, it would be expanded to use 250 t/day of woodchips.

In another Canadian development, a Winnipeg-baaed Crown corporation, Canertech Inc., has been designated the lead agency in developing ethanol-from­ cellulose technology. Canadian Energy Minister Marc Lalondes announced a $5 million, 3-year Canertech programme to develop a pilot plant and a related research and development programme for producing ethyl alcohol from cellulose materials such as aspen, poplar and . Plans are to break ground in September 1983 for an ethanol pilot plant that will use 1 t of aspen-wood feed­ stock/day. Start-up of the plant is expected by the spring of 1984. A larger demonstration plant, which would use 50 t of feedstock/day, is intended for construction in 1986.

In other plans for an ethanol-from-wood plant, Biological Energy Corp. of the United States, supported by General Electric, hopes to start construction of a plant using aspen chips as feedstock. However, although ethanol was the primary reason for planning the plant, the main product, at least in the beginning, would be woodpulp for the paper industry. Eventually, the company-also hopes to produce lignin for the plastics industry. Hemicellulose sugar produced from the wood feedstock might also be converted to wet ethanol. The $12 million plant would use about 45 t of green aspen/day.

Development of plants to convert wood to methanol is lagging compared to world-wide activity aimed at ethanol production, Nonetheless, methanol has the potential for providing more liquid fuel (on an energy-equivalent basis) from wood at lower cost. To produce high yields from wood, gasification of wood, pro­ duction of synthesis gas, and catalytic conversion to methanol are required. Optimization of the wood gasification step has been a stumbling block in imple­ menting wood-to-methanol technology. Another competitive factor in the United States is large deposits of coal. Because large supplies of coal are capable of supporting plants with capacities of 20,000 t/day or more, coal plants to make methanol would probably be more economic than wood plants of smaller capacity. On the other hand, impurities in coal such as sulfur and heavy metals make coal plants of comparable equivalent size more expensive. - 343 -

In Brazil, coal is less competitive than in the United States. Brazilian coal deposits are meagre and of lower quality. Brazil has hopes of soon converting eucalyptus on the Parana River to 100 t of methanol/day. Partial financing of such a project has been provided by a $26.4 million 20-year loan at 9.25 % interest from the Inter-American Development Bank. Three pilot plants are to be built to test the technical and economic feasibility of gasification processes. Davy McKee of the United States, Uhde of the Federal Republic of Germany and Energy Corporation of São Paulo (CESP) are cooperating in this project at Juquia, Brazil.

Evergreen Energy, Inc., proposes to build a 100-million-gal/yr (380 million L/yr) wood-to-methanol plant. The plant would use a Texaco high-pressure coal gasifier. Tests are to be run during 1982 at Texaco's gasification laboratory in Montebellow, California. The experimental gasifier is designed to use 1 t of coal feed/day. For the large plant, methanol production cost is estimated at 87.6 cents/gal (23.1 cents/L) with wood price at $35/dry ton ($38.60/dry t).

In Canada, Biosyn - a joint venture of Canertech, Quebec's Nouveler, and Canada's Federal Department of Energy, Mines and Resources - proposes to convert wood to methanol. For the project, each sponsor will contribute $5 million, and Omnifuel Inc, will supply an -blown fluid-bed gasifier. A preliminary engineering study is under way.

Other chemicals Other chemicals from biomass axe being considered for use as fuels, but none are at the pilot-plant stage of development. Possible chemicals under consideration include butanol, acetone, ethyl acetate and acetic acid.

Other research has been aimed at converting woodchips into oil. Pre-hydro­ lysis under mild conditions is followed by wet grinding. Upon addition of 6 parts of sodium carbonate per 100 parts of pre-hydrolyzed biomass, the slurry and synthesis gas are injected into a reaction vessel maintained at 3,000 lb/in2 (20,700 kPa) and 350°C and given a residence time of about 45 minutes. Using this process (called the LBL process) with variations imposed by equipment limi­ tations, about 10 barrels of oil have been obtained at the biomass liquefaction development unit (PDU) of the Department of Energy at Albany, Oregon (4).

Still another potential source of liquid fuel from wood is naturally occurring chemicals that may be extracted.

According to "Science" (October 1979), a unique tree in the Amazon jungle, Copaifera langsdorfii, produces an oil similar to diesel fuel. In Japan, research is aimed at using eucalyptus oil as an alternative to . Sukezo Takeda, Faculty of Agriculture, Mie University, Kamihama-cho, Tsu-shi, Mie-ken, Japan, has carried out comparative tests of gasoline, a 70/30 eucalyptus oil/gasoline blend, and 100 % eucalyptus oil at the Mitsubishi Heavy Industries Nagoya plant.

According to Professor Takeda, power output and fuel consumption per horse­ power were nearly the same for the three fuels. Pure eucalyptus oil had an octane rating of over 100 and, when used instead of gasoline, cut concen­ tration in engine exhaust by about half. Eucalyptus oil also had better anti­ knock properties. Using eucalyptus imported from Australia, the cost of producing test quantities of oil is estimated to be about $35/gal ($9.25/L) but the commer­ cial cost would be expected to drop drastically if eucalyptus farms were developed in Japan. Blends with gasoline are most promising.. Tests with other types of engine are contemplated. - 344 -

CONCLUSIONS AND RECOMMENDATIONS

As indicated in the examples cited, liquid and gaseous fuels from wood have potential for providing some of the world's energy needs. Today, relatively few wood gasification, hydrolysis and fermentation plants are in operation, but the use of producer gas from wood is growing. In recent years gasifiers have been made more dependable. Fermentation alcohol continues to be made from the waste liquor of a number of sulfite pulpmills and hydrolysis plants still operate in the USSR.

Characteristically, improved fuels from wood, particularly liquid fuels, have been of major concern only during times of national emergency. Now, petro­ leum supplies are dwindling and becoming a major and increasing source of balance­ of-payments deficits to many countries. As a result, alternative fuels, including those that are wood derived, are more popular. The intensity of this popularity rises and falls with fluctuations of prices and availability of oil on the world energy market. But oil depletion is sure and continuous. Eventually we must turn more to substitutes from renewable resources. Through research and demon­ stration, we must develop the best technology possible to prepare for replacing at least a portion of our petroleum-derived fuels with wood.

Literature Cited

1. Anonymous. 1982. Cellulose-to-alcohol facility will be Brazil's first. Forest Products Journal, Madison, Wis. January.

2. Beglinger, Edward. 1956. Hardwood-distillation industry. Forest Products Laboratory Report No. 738. For. Prod. Lab., Madison, Wis.

3. Cornwall, George. M. 1937. Mill driven by wood gas. The Timberman, Portland, Oreg.

4. Ergun, S., and N. Yaghoubzadeh. 1982. Bench-scale studies of biomass liquefaction with prior hydrolysis. Lawrence Berkeley Laboratory 12543, Berkeley, Calif.

5. Evans, R. S. 1977. Energy self-sufficiency prospects for the British Columbia forest products industry. Western Forest Products Laboratory, Vancouver, Canada.

6. Fritz, Jack J., Judith J. Gordon, and V. Thanh Nguyen. 1979. Status review of wood biomass. Gasification, pyrolysis, and densification technologies. The MITRE Corporation, McLean, Va.

7. Hough, Franklin B. 1878. Report upon forestry. U.S. Government Printing Office, Washington, D.C.

8. Lloyd, Roger A., and John F. Harris. 1959. Wood hydrolysis for sugar production. Forest Products Laboratory Report No. 2029. For. Prod. Lab., Madison, Wis.

9. Mellenger, E. Ray. 1977. Gasification of forest and field fuels. Symposium of Forest Fuels, Biomass Energy Institute, Winnipeg, Canada.

10. Overend, R. 1977. Wood gasification: An old technology with a future. Symposium of Forest Fuels, Biomass Energy Institute, Winnipeg, Canada.

11. Pearl, Irwin A. 1982. Utilization of byproducts of the and paper industry. Tappi 65(5). Zerbe, John I. Wood production of liquid or gaseous fuels. In: United Nations Economic Commission for Europe. presented to the seminar on energy conservation and self sufficiency in the sawmilling industry; 1982 September 13-17; Bonn, Federal Republic Germany. Bonn; 1982: 333-344.