The Utilization and Mechanical Separation of Sugar Cane Bagasse

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LSU Historical Dissertations and Theses Graduate School

1955 The tU ilization and Mechanical Separation of Sugar Cane Bagasse. Robert Marius Hansen Louisiana State University and Agricultural & Mechanical College

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Recommended Citation Hansen, Robert Marius, "The tU ilization and Mechanical Separation of Sugar Cane Bagasse." (1955). LSU Historical Dissertations and Theses. 104. https://digitalcommons.lsu.edu/gradschool_disstheses/104

This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. THE UTILIZATION AND MECHANICAL SEPARATION OF SUGAR CANE BAGASSE

A Dissertation

Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in p a r tia l fu lfillm e n t of the requirements for the degree of Doctor of Philosophy

The Department of Chemical Engineering

by Robert Marius Hansen B.S., Louisiana State University, 1950 M .S., Newark College o f E ngineering, 1953 June, 1955 EXAMINATION AND THESIS REPORT

r Candidate: Robert M. Hansen

Major Field: Chem ical Engineering

Title of Thesis: The U tilization and Mechanical Spcaration of Sugar Cane Bagasse

Approved:

Major Professor and Chairman

adunto School

EXAMINING COMMITTEE:

■ ■ T/

-7T

Date of Examination:

May 11, 1955

PIRC SUROIN IIBEHI I l l CF I B S 11, Furfural from B agasse ......

Page ho, 12, C attle Feed fro i B ag a sse ...... H e author wishes to thank h r, Arthur 5, Keller, without vhose 1 ), Hisccllancous Ises of Bagesse • ■ > • • ■ran ...... i i pidance tliij lisaertation would to e hew wth nore difficult. Dr, P, II, IK ( M U ...... ii M i l , E M U ...... Horton contributed to the original desip of this apparatus, therelj set* IMF* ...... v iii 1, S olution of the Bagasse Separation Plant ■ ting the patten for fotiiro vorh in the field of bagasse separation. I, Apparatus...... MUMI ...... * t a b are alio expressed to Hessrs, E, E, Snyder, 1.1, Stciart I l f ...... x ii 1, Bagasse Separation P l a n t ...... and 1 1. Clark, vho assisted is conducting tie experimental work for ■ H I ...... 1 2. Small Hamer H i l l...... this project. cm. niisui...... i J, Rotary Digester ■ - ...... Appreciation is also extended to Hiss I. larlste, of tie lefereatc U i y i n j k r ...... 1, historical...... 8 Departient, Krs, 1 . 1. C o k r , fro i tie h i s t i j Library, and Mrs. K, C, Cperatioi of the Bagasse Separation Plant > Early Evidence of Bagasse U til is a ti o n 6 Hanchey, f r a ti e Agricultural-Biology Library. I, Procedure for P ulping . Reviev of Several Conprthensive Studies of Hany students contributed to the success of this project; I, E, Bagasse U tilita tio n ...... ! E, A n aly ses...... M r , H. F, 1, Fontaine, S. ! , Knapp, and n itro n s senior cheaical rocuring and U tilising Bagasse F, R e su lts...... engineering students. Production T re n d s ...... C, Biscussion of R esu lts ......

1, YariablesAffectin; Amount of Separation se ■ 2, Variables Affecting Power Consaption • Louisiana Purchase Contract for Bagasse 1, Ash Contents of Bagasse, Fiber and Pith

I , Properties of Bagasse, Fiber and Pith >

5, tra in V ate r......

Ii, Evaluation of Fiber Product ......

1, Bagasse Flow Problems ......

E, Conclusions ......

iii Page No.

APPENDIX I; Economics of a Dagasse Separation Plant ------160

APPENDIX II. Definitions and Abbreviations ------165

APPENDIX I I I . Summary o f C a lc u la tio n s ------168

A. M ate rial Balance ------168

B. Sample Data and Calculations ------172

C. S t a t i s t i c a l C a lc u la tio n s ------177

VITA------193

v LIST OF TABLES

Table No. Title Page No.

I Recapitulation of Final Manufacturing Reports of Louisiana Sugar Cane Factories, Crop 1952-53 14

II Data for Power Consumption and Feed Rates of the Bagasse Separation Plant 81

III Instantaneous Power Consumption for Individual Hammer Mills of the Bagasse Separation Plant 83

IV Load Factor on Hammer Mills and Accessories of the Bagasse Separation Plant 84

V Ash Analyses of Feed and Fiber Product for Dry Operation of the Bagasse Separation Plant 85

VI Ash Analyses of Feed and Fiber Product for Wet Operation of the Bagasse Separation Plant 8b

VII Ash Analyses of Fiber and Pith from Each H ill of The Bagasse S ep aratio n P la n t 87

V III Summary o f P er Cent Ash in th e Bagasse Feed and Per Cent Ash in the Fiber Product for Various Operating Conditions of the Bagasse Separation P la n t 88

IX Analyses of Bagasse and Fiber Ash for Si02 and Fe203 89

X P er Cent o f Feed Removed a s P ith from th e No. 1 Mill Only (Dry Basis) 90

XI Total Pith Removed/Feed Ratio (Dry Basis) 91

X II P ith from th e No. 1 M ill/T o ta l P ith Removed From the Bagasse (Dry Basis) 92

XIII Data for Power Consumption and Feed Rate for Various RPM o f the Sm all Hammer M ill 93

XIV Per Cent Solids and Per Cent Mud in Water from Strainer Tanks of the Bagasse Separation Plant 95

v i Table No. Title Page No.

XV Particle Size Analyses of the Fiber Product fro® the Bagasse Separation Plant 9b

XVI Bone Dry Density vs. Pressure for Fiber and Pith 97

XVII Results of Analyses of Fiber for Desirables and Undesirables 100

XVIII Properties of Kraft Pulp Produced from Dry and Wet Separated Fiber and Bagasse 101

XIX Identification of Samples Sent to Celotex Corp. 105

XX Yield of Pulp from Dry and Wet Separated Fiber Using a N eu tral S u lf ite Cook 10b

XXI Summary o f the A nalysis o f V ariance fo r th e Yield of Pulp from Dry and Wet Separated Fiber 107

XXII Permanganate Numbers of Pulps from Dry and Wet S ep arated F ib er Using a N eu tral S u lf ite Cook 108

XXIII Summary o f th e A n a ly s is o f V ariance fo r the Permanganate Number of th e Pulp from Dry and Wet Separated Fiber 109

v i i LIST OF FIGURES

F igure Ho. T itle Page No.

1 Location of World's Sugar Producing Areas 11

2 World Production of Cane and Beet Sugar, 1910 to 1952 12

3 Effect of Pith Contention Pulping and Bleaching Bagasse 37

4 Flov Sheet for Production of Pith and Fiber 62

5 Bagasse Separation Plant 63

6 Bagasse Drying Tower 69

7 KWH/Lb. Wet Feed v s. Wet Feed Rate 110

8 KWHt/Hr. v s. Wet Feed Rate 111

9 KWti/Hr. v s. Water Rate 112

10 Per Cent Ash in Bagasse vs. Per Cent Ash in Fiber for Dry Operation 113

11 Per Cent Ash in Bagasse vs. Per Cent Ash in Fiber for Wet Operation 114

12 Per Cent Ash in Fiber vs. Pounds of Water per Pound of Ash in Feed x 10*2 1 1 5

13 Per Cent Feed Removed a s P ith from th e No. 1 H ill v s. Screen Size, Dry Basis 116

14 KWH per Pound of Feed vs. Feed Rate for Various RPH of Small Mill, Dry Basis 117

15 Pounds of Pith/Pound of Feed vs. Feed Rate, for 1135 RPH of Small Hill, Dry Basis 118

16 Pounds of Pith/Pound of Feed vs. Feed Rate for 795 RPH of Small Hill, Dry Basis 119

17 Per Cent Solids in Drain Water vs. Pounds of Water per Pound of Feed, Dry Basis 120

v i i i Table No, Title Page No.

18 Weight Per Cent Solids in Drain Water vs. Per Cent Mud 121

19 Average Particle Size Distribution 122

20 Pressure vs. Density for Fiber and Pith 123

21 Feet of Bagasse, Fiber, and Pith vs. Pressure Drop 124

22 Typical Plot of Temperature vs* Time for Pulping F ib e r 125

ix LIST OF ILLUSTRATIONS

P la te No. T itle Page No.

I Section Through Outer Part of Cane Stem 27

II Structure of the Vascular Bundle and Surrounding S to rag e C e lls 28

III Parenchyma or Pith Cells 29

IV M ill No. 1 , Lid Removed 64

V Mill No. 1, Assembled 64

VI M ill No. 2, L id Removed 64

VII Mill No. If Assembled 64

V III M ill No. 3 , Lid Removed 64

IX Mill No* 3, Assembled 64

X Control Panel, Bagasse Separation Plant 65

XI Water Meter and Water Control Valves, Bagasse Separation Unit 65

XII Spencer Rotary Digester 65

XIII Moisture Tellers 65

XIV Apparatus for Determining Ash in Bagasse 65

XV Saccharimcter 65

XVI Main Feeder Scroll 66

XVII Mill No. 3 Feeder Scroll 66

XVIII Mill No. 2 Feeder Scroll 66

XIX Bucket £ le v a to r bb

XX Fiber Strainer Tanks 66

XXI Pith Discharge Scroll and Fiber Product Tank 66

x haulers in each of the three mills, I portion of tbe pith is forced apart F lat! Do, T itle Page lo . f r a tie f ile r in each m ill and passes through a screen which is located SHI Fiber attd Pith Strainer lankj, Plan licia 66 AHS1C1 directly beneath the hammers. He leads of tie mills are designed so, that K i l l Snail Hamer H ill, issenbltd el During the p i t ISO je a n , numerous schemes for the u tiliia tio n vater or steam nay be injected into tbe bagasse as it progresses through 1 1 V H u ll t e r H ill, Lid fieooved 61 i f bagasse bat! been proposed. Duly a fcv uses, other than aa l t d , have Ilf Inside Viev of Ud for Snail ikner Kill,Sloping the m ills. Head 61 proven c c o ra ic a lly sound aid a lev sugar s ill s can usually supply the f a s were made on tbe more compact unit f r a tie M grinding 1 Experioental Digester for Pulping 61 bagasse required for these. One of the potential uses uhich might con- season through tbe 1 season during vtich tin e improvements vere made f f l l l Htthod of Pulp Kashin; 61 sinc the tremendous quantity of bagasse th at is available throughout tbe until tbe plant v ill now handle over 1 tons of rav bagasse per hour at ffllll havllagasse 68 vorld, is tbe paper and tbe vail board industries. Many investigators m tiini capacity, host of the data included in this report are fra tbe I H I Fiber Fraction frosa Bagasse Separation Plant 116 are agreed that to make a high quality paper f r a bagasse, it is essential '52 to W seasons during i c l tine the author vorked vith the Separation IQ Pith Fractk fra Sagasie Separation Plant ' 68 that tbe juice bearing cells, pith, and site of tbe dirt be rawed fra F lin t. the bagasse fib er. I t vas determined tbat the vet separation vas le tte r than the dry, f a y processes, botb chemical aid mechanical, bale been suggested but nore problems arc encountered in handling and storing the vet fiber for separating tbe pith fro i tbe fib e r. Ibe chemical methods v ert general and p ith , H e amount of separation obtained and pover consumed vere i f ly too costly and many of tbe mechanical ones in e fficien t, i f t e r a review tenined as a function of the muler of lills used, feel rate, the mill indicated tb at tbe mechanical separation method appeared to offer tbe best screen site, rotary speed, and vet or dry separation, lie pover consump* possibilities, research vas started on this subject at Louisiana State tien per l i t of product vas improved considerably i f only two m ills vere University, in M used and a high feed rate maintained, lhe le s t fiber product is obtained Preliminary investigations using a specially designed suing bluer v ith large screens and a n i i i vater rate, and tbe poorest vith small mill in conjinction vith a flotation tail shoved tbat a fiber product re* screens and no v ater, Since various products require different amounts latively clean and free of pith could be obtained, lie next step vas tbe of separation, conditions nay be chosen anywhere between these e t a s , censtnction of a s e m r c ia l sisc pilot plant. It vas soon discovered He evaluation of the fiber product as a rav material for paper slovs th at tbe flotation cants vere not necessary and tbe plant vas then remodel that it is vastly superior to normal bagasse aid that tbe vet separated ed into a lo re compact l i t composed of three swing h i i e r m ills. fiber is better than tbe dry for a quality produet, lhe vet separated filer In this separation plant, tbe bagasse passes across tbe top of the requires very little additional refining for vallboard production.

ji ni xiii INTRODUCTION

The manufacture of cane sugar dates back several hundred years.

Bagasse, the fibrous residue from the grinding operation, has long been n source of trouble to the m ills. Because of its low density, if allowed to accumulate at the sugar m ill, it becomes a great nuisance. It can be used successfully as a low grade fuel and practically all of the world*s production of bagasse is burned. In some cases, factories may produce more steam than is required for the operation of the sugar mill because of the excess bagasse. Where this is the case, the furnaces arc usually operated at low efficiencies to provide a means of disposal.

The sugar in d u stry in many a re a s is exceedingly co m p etitiv e, and tbe margin of profit is low. Investigations into different aspects of the use of by-products from these mills has been made in an effort to improve their financial position. Bagasse, which is one of the major by-products, is produced by the mills at the rate of about 25 million tons per year. If this enormous quantity of material could be put to a successful commercial use, it would both increase the margin of profit for a low return industry and provide more income for the areas produc ing sugar cane.

Over the past 150 years there have been many ventures into the oommcrcial utilization of bagasse. A very few have succeeded. Probably the most outstanding success in this country is that of the Celotex 2

Corporation. The reasons for the success of this company seem to be two fold. (1) Advantage was taken of an inherent property of bagasse to produce a quality product which could not easily be duplicated by use of any other raw m aterial. (2) An extensive sales promotion program was undertaken. However, even with the vast market offered in the United

States, this use only accounts for about 25% of the bagasse production of Louisiana. Some bagasse board is now being produced in Hawaii, Taiwan,

Peru, England and Australia. An additional 5% of Louisiana bagasse is used for animal litte r and agricultural mulch.

The field of utilization of bagasse which has received the great est amount of investigation over the past century is that of paper manufacture. A historical review of the more serious experimental work combined with a study of present day successful commercial operations shows that the following items should be considered by workers in the f ie ld .

(1) Except for use in wall board, corrugation, etc., it is essen tial to separate the pith from the fiber to produce a high grade product.

(2) Pith free fiber is an excellent raw material for the production of pulp and paper.

(3) Pith free fiber can be converted into pulp by any of the ordinary pulping processes or well known modifications.

(4) The choice of the various processes available is a matter of economics, depending on the specific location.

Since the key to the successful use of bagasse for pulp production lies in an efficient and effective commercial means of separating the 3

pith and dirt from the fiber, two general methods have been proposed; chemical and mechanical. The chemical methods were found to be too cost ly and many of the mechanical ones proved inefficient. The dry mechanical separation is not a sharp one and the fiber still c cm tains much dirt. It has been shown that the wet separation of the fiber and pith results in a higher quality fiber.

Because of the importance of the sugar industry to the economy of

Louisiana and the tremendous interest in methods for making better use for bagasse, the Board of Supervisors of Louisiana State University authorized by resolution, the creation of a fund of $50,000 to be used in a study of the possibility of using certain sources of cellulose not at present used commercially. It was understood that this source would be bagasse. A stipulation that this work was to be done by the Department of Chemical

Engineering was made.

The Department studied the problem at some length. This included a review of the previous commercial attempts at bagasse utilization and the reasons for their failure. As a result of this study, the conclusion was reached that one of the factors of prime importance to the satis factory use of bagasse for paper production was the elimination of the pith fraction from the bagasse prior to pulping. A study of separation methods showed that most of them were either impractical or prohibitively expensive. This led to a study of better methods for pith separation.

As a result, a simple, inexpensive mechanical process was developed and patented. During the course of this work, a pilot plant was built to in vestigate all phases of the new process. In this dissertation the results m l i t l i d probably lie safe to a s s w tb i t cane f ile r b o aong those tk t be tried, t e e early expcriients are generally considered to le tie begitining of tie manufacture of p as ve b a r i t today!5),

1 study ly tie Department of C m e r o e M k i t e a survey of ooicrcial attempts to use lap*111 Mtr ^ °5

cess for tie utilisation of lagasse in p dates lacl to ISIS, Litkenhous mentions tb a t in 18ft W e d g e attempted to use lagasse as a su lstitu te for rago io p , lie first attempt to use lagasse for p stool vas in 1884, vhen tbe m aterial i s slipped to France fro i the Island of

Hartinquc. Also in th is year, tie le v Orleans Daily Picayune i s printed on a p u d e np of % lagasse, pins SDji rag content, H uy pulp and paper n ils vhich used lagasse as a rav material vere tried or planned, lie deletes Corporation located at H arm , Louisiana, i s tie first to produce, successfully and economically, predicts manufactured from lagasse. lhe success of tie Celotex ( o p t i o n depends on a high yield of product froi lov cost leclanical operations npon tbe lagasse. It is said ly tbe 7

Celotex Corporation that most failures in papermaking attempts with ba

gasse were due to the high conversion cost for chemicals, power, labor,

etc. This indicates that any anticipated utilization of bagasse should be studied very thoroughly from an economic point of view.

Along with the development as a raw material for paper, attempts were made to use bagasse as a fuel. Since early mills were very inef

ficient, the bagasse contained large amounts of moisture. As a result,

Reedy^^) states that it is not surprising that some of the first pub lished works are patents for the drying of bagasse. Some of these were issued before 1850. In 1911 Kerr published the most valuable work in this ficld ^ ?) • As the milling process improved it was found that the bagasse could be burned without drying.

The first patent involving the design of a bagasse furnace was that of Marie(147) in 1881. After this, much attention was focused on the design of furnaces. The use of bagasse as a fuel was successful be cause it not only offered a method for the elimination of a nuisance by-product, but also produced heat for evaporation of water from the ex tracted juices. The burning of bagasse is of such importance that today the price of bagasse for any other use is generally determined by its replacement fuel value.

The burning of bagasse with other fuels, generation of producer gas, briquetting, making glass from bagasse ash, and even an attempt at making a substitute for smoking tobacco have been tried in attempts to find outlets for bagasse. 8

(2) Review of Several Comprehensive Studies of Bagasse Utilisation

There have been several comprehensive literature surveys made of bagasse utilization in the past. One of the first of these was by

Reedy^^) in 1932, which lists some 414 references. These cover com position, uses, and other general topics. Some 94 of the references have been abstracted.

An extensive literature search on sugar cane bagasse in connection with the War Production Board Project No. 547 was carried out in 1944 by

Litkcnhous^). There are some 849 references in this report concerning bagasse. Some of the conclusions of the work are listed below:

(1) All early work recognized the advantages to be gained by using bagasse as a source of paper and/or alpha cellulose.

(2) Bagasse was treated by methods similar to those developed for pulping wood and such treatments were too drastic. Bagasse was not handled according to its own physical properties.

(3) Where bagasse was cheaply separated into fiber and pith, the utilization of bagasse has been economically feasible.

(4) Many paper products can be made, using about 55# of bagasse on a bone dry basis.

The cost figures in this paper are out of date, but they still give relative values.

An annotated bibliography compiled by C. J. West^23) in 1952 is quite comprehensive. It includes some 541 references on bagasse. They are divided into three general groups: (1) pulp, paper and board, (2) plastics, and (3) chemical and miscellaneous studies. 1 paper Ip S c o tt^ in 191V reported od sugar cane by-products, I , fROClHG I UTILIZING BAC/ISSE lie vork report! oo the estimated surplus of bagasse for most factories

io tbe H e m area, Ibia verb did lot include a bibliography as mob, I t is beetling evident that the economic s tab ility of the cane

but did include some references as footnotes. sugar industry may bo aided by extracting several major products from

Accent information concerning bagasse baa been published b j tbe sugar cane instead of sugar alone, For th is reason, bagasse, the indus

United la tio n s M , try's major by-product has received the attention of many investigators,

The subject of chemical and mechanical separation of bagasse vas The methods for u tilisin g bagasse have been limited only by the imagi

covered in a th esis by lin lc r in 1 9 5 9 ^ 1 This vork baa some 92 re nation of the inventor, This has caused a great increase in loth the

ference!, covering a period from U J1 to 1947, Ib is thesis also covers m b e r of publications and the fields into vhich it s uses have gone,

the original vork on the bagasse separation unit a t Louisiana State The lite ra tu re is becoming even more v o liin o u s than indicated ly the

University, previous section. Because the fields of u tilisatio n are so numerous,

Considerable vork vas done by la tlro p and Aronovskyl®) on tic I s literature survey has boon divided into appropriate sections, Al

pulping of agricultural residues for tie production of paper products. though the successful u tilisatio n of bagasse may involve several of these

In the course of their investigations they foid tbat it u s essential to sections, a b etter overall vicv can be obtained ly the grouping of infor

separate the pith from lagasse for tie production of fine papers loth mation into such topics as production trends, production methods, calculations

frem the standpoint of yield and the quality of tbe resulting p u lp M , concerning bagasse, purchasing, handling and im position, Other sections,

They found th at the Hydrapulper developed and designed ly the Black- such as it s use for fuel, paper, board, p la stics, furfural, ca ttle feed

Clavson C o p y eould be used to great advantage in the pulping of and miscellaneous products, are included,

agricultural residues and vith a ftv modifications the same apparatus (1) Production Trends, vould separste a considerable quantity of path f r a bagasse, I Atchison d e s c r i b e d ^ a bagasse separation plant v lic l vould Figure 1 slovs the principal areas of the world where sugar cane

employ Hydrapulpers, Data are given on equipment, investment, capacity is g ro w W and hence, the areas in which bagasse is produced, From and operating costs, Figure 2, one may sec the general trend of vorld sugar production^),

IB Million tons, raw value P 0 2 4 6 I 0 2 4 6 1 0 2 4 6 1 0 2 4 6 1 0 52 50 41 46 44 42 40 31 36 34 32 30 21 26 24 22 20 II 16 14 12 1P10 bu totid o to ol' sgr upy oe fo sgrae The sugarcane. from comes supply sugar world's tho of two-thirds About rprin nrae i bt wrd wars. world both in increased proportion Fgn hwn tho showing (Figvns prior to prior RP ER I sm cutis avsig eis nte ol f h peiu year. previous the of foil the in begins harvesting countries somo CROP YEARS In • RD ON O CN AD ET UA, 0 T 1952 5 9 1 TO )0 9 1 SUGAR, BEET AND CANE OF N iO a U D O R P ORLD W 1936 ore not available) not ore 1936 production of centrifugal centrifugal of production iue 2^20^ Figure and non-centrifugal non-centrifugal sugar soparoMy sugar

Million Ions, raw value 12 13 14

t» Ifl B B rIO W B 9lrlB lAOWBBHNWBB’t 9l N 0 W W H ifl Ifl N N W N, 00 . 0 91tf NBNO , , , • OBrl . • • W O «* WWH® OWN Ifl N N W Ifl N W 0 0 W 91 ifl H WW rliflNOO HrH N rlrl 919lrlrlN 0 W to the next. An exception to this vould occur i f one used only surplus iflW 9 I BOO bagasse from one or two mills. In this case, items such as furnace ef ficiencies, variations in fiber content of the cane, and mill efficiencies, H H 00 N N 91 ^ W 91 rl 91W W N COW BWQB OBW OlOlONWNWNOBB vould determine the quantity of bagasse available. An unfavorable grov- 91« WB ^ 91 INO I I 8 * ONO * * I &hn 2 00 « « BNNB ifl^N H NO rlONB rlrIN iiiiiiirH Wrt 9191 k A toII

a 8 N 91N N 9191N B W W I) iflN 0 0 000W 00 91N N NNW 910 N OlfliNrlBNWNWNBZ duction vas made by the Department of Commerce^). It includes detailed a < 008 .... • • . H WO W » * W NO B NBOi ONNBONW N9IW8I rl OW WN8 rlrIN HH9I9IHHNB WOC s CON information on practically all of the Caribbean area, Louisiana, Hawaii; rl H 8II 3 and Cuba. Figures for many individual mills are given. Estimated fig •9 09 ures for 1950 and 1951 production for the vorld, broken down by country, WN0BWN8HNW9I'*' 8 rl NN Blflfl 91B W giB09lWNWB0N0 N 8 Brl OONN 0W9I ...... i . . are given, Of the approximately 25,000,000 tons of bagasse produced, N9l* 0 . NN9i • • 1 BWO * • • 8NNW8NWB0W9I 8 ifl 0 N N8 rlrlN HBM4W0 s a 10 Ifl 0 about half is produced in the Western Hemisphere. Cuba is the leading in 5 88 * » H BB

V tons. nI. li I. V 2 I) noil II 0 J figures or. sugar production vhich can be related to bagasse, The issues o z 0 9h K iirl '9 a u id fa If 3 dw StSi of Gilmore Sugar Manuals^11' 12’ give production and trends for the M W >H . 5“ 3 3 8 #' m felffiWCU SB 9 00 IlflvO O.UOU 1 u U V II II II 3'H If # vorld's sugar areas, The following chart (Table I) shows typical data n.i •H H If y 0 » « h a. 0 -H 3 3 0ld'H'3'HWiNl3 b 3 3 3 8 CHS 9 hTW.H „ n If |< id U M o t ) available on factories in Louisiana^51*)!57), 3988O'H sis UltlUMHHHLiJWM Document L.5,0 of reference 22 considers the various factors vhich tttss B s s a s H b ts s 0 I If tl 0 II Id ^OOBBZZZtKBBJ L C If 3 0 0 0 # I) S K 0 . 3 S'H m influence the supply of bagasse. VtHHW Sin*) 5 TABLE I (Continued)

STATE GROUPS I + I I GROUP I I I GROUP IV GROUP V 54 3 12 9 30 FACTORIES FACTORIES FACTORIES FACTORIES FACTORIES

Bagasse Fiber 45.75 44.39 45.22 45.84 45.92 Press Cake—Sucrose 3.81 4.15 4.18 3.12 3.86

SUCROSE BALANCE: Molasses, Sue. in, % Cane 1.164 1.306 1.227 1.187 1.138 Press Cake, Sue. in, % Cane .156 .170 .169 .107 .162 Undetermined Sue. in, % Cane .177 .696 .277 .233 .117 Bagasse Sue. in, % Cane 1.014 1.447 1.114 1.112 .947 Total Losses, Sue. in, % Cane 2.511 3.619 2.787 2.639 2.364 Sugar Sucrose in, % Cane 7.390 6.546 7.205 7.159 7.525 Total Sucrose in, % Cane 9.901 10.165 9.992 9.798 9.889

Lbs* 96* Sugar M. and E. Ton Gross Cane 153.96 136.37 150.10 149.14 156.77 Lbs. 96* Sugar M. and E. Ton Net Cane 159.46 142.10 154.58 154.44 162.54 Gals. F.M. (B/S) M. and E. T/C 80 B rix 7.82 8.33 8.38 7.79 7.68 Boiling House Efficiency 97.83 87.10 95.34 95.61 97.37

GROUPS I and II - Ten rolls or le s s 2 / GROUP IV - Twelve and Thirteen Roll M ills GROUP III - Eleven Roll Mills GROUP V - Fourteen Roll Mills

1f All calculations based on gross weight. 2/ All mills equipped with one or more sets of knives.

Prepared by V. M. Grayson Sugar Marketing Specialist March 24, 1953 La. State PMA Office 16

(2) Production of Bagasse

Bagasse is produced as the by-product of the process used for the

extraction of the sucrose from sugar cane. Its freedom from extraneous material depends on the method of harvesting. In Hawaii the cane is

picked up and broken off at the roots at which point the stalk breaks

easily. Much trash and dirt are picked up in the cane by this method

and laundries are usually installed to clean the cane of trash, rocks,

and dirt at the factory* Mechanical harvesting is practiced in

Louisiana, and often the cane is burned in order to facilitate handling,

particularly where labor is expensive. These practices result in much

trash, dirt and carbon particles finding their way into the bagasse.

Thus, the above items become important in the consideration of any ba

gasse utilization scheme^7) .

Hand c u ttin g , which r e s u lts in much c le a n e r cane, i s common

practice in many parts of the world. The stalks arc cut off close to

the ground and topped at the highest colored joint. Occasionaly, the top

joint or two is saved for seed. The leaves arc removed at the same time

that the stalk is cut^7).

Once the cane is harvested the juice is extracted by a series of knives, crushers, and m ills. The physical size of the bagasse particles

produced is a function of the type of m ill. When two smooth rollers are used the cane emerges in ribbons about two inches wide and five to six

feet long. When a crusher and three roller mill are used, it emerges in

the same ribbon form but about 14 inches in length. When knives, shredders \

and mills are used there is a large per cent of fines, sometimes as high as 15 to 20 per cent^-^). Most bagasse varies between the last two types. Usually about 97$ of it will pass an inch square opening^6®).

The milling of sugar cane, using knives, shredders and m ills, will be discussed in more detail. The milling process may be separated into two steps: (1) the preparation of the cane by breaking down the hard structure and rupturing the cells; (2) the actual grinding of the cane. The preparation is accomplished in several different ways: by revolving cane knives which cut the cane into chips but extract no juice; by shredders which tear the cane but extract no juice; by crushers that break and crush the cane, expressing a large portion of the juice; or by a combination of any or all of these means. The cane then passes from the preparation through three to seven sets of three-roller mills. The woody residue from the first and subsequent mills is termed bagasse. As the bagasse passes through the mills it is compressed more and more, each time parting with some of the residual juice. Under good conditions the bagasse emerges from the last mill at about 50$ woody fiber. Most factories add uater to the bagasse coining from each mill or use the di lute juice from a subsequent m ill^ ^ .

The structure of cane has a very marked influence on extraction.

The bagasse may vary from 50$ fiber and 45$ moisture to 45$ fiber and 50$ moisture for the same mill when processing different types of cane. The greater the amount of fiber the less the extraction. Also adhering leaves, dirt, and tops of stalks will adversely affect the extraction. The aver age percentage extractions for Hawaii, Australia, Java, and Louisiana are 18

95.5, 95.5, 94 and 93$, respectively^*?).

It nay be seen from the previous discussion that the particular type of bagasse obtained from a sugar m ill would depend on the type of mill train, the method of harvesting, and the efficiency of the m ills.

(3) Calculations Concerning Bagasse^**^)

The International Society of Sugar Cane Technologists makes the following recommendations for the control of the cane milling operation: nThc fundamental equation for the weights of the products entering and leaving the mill states that cane plus water equals mixed juice plus bagasse. Unfortunately, no practical weighing machine for large scale operation is available; therefore, the weight of bagasse has to be de termined indirectly. Many methods have been used, but two are recommended by the Society.

(A) The weight of the imbibition or maceration water is determined as such or is derived from its volume, and the weight of the bagasse is found by applying the fundamental formula given above. This system is used in a number of countries.

(B) The fiber per cent cane is directly determined in samples of the cane, and the bagasse per cent cane calculated from fiber per cent cane and fiber per cent bagasse. The weight of the imbibition or macera tion water is then calculated by the fundamental formula.11

Several calculations based on these two methods are of interest, but first one needs to obtain the following two items:

(1) Brix per cent bagasse equals pol per cent bagasse time Brix 19

per cent last expressed juice* divided by pol per cent last expressed juice; (2) fiber per cent bagasse equals dry substance per cent bagasse minus Brix per cent bagasse.

For scheme A based on the imbibition water one obtains the follow in g :

(1) Weight of bagasse equals weight of cane plus weight of im bibition water minus weight of mixed juice.

(2) Bagasse per cent cane equals 100 times weight of bagasse divided by weight of cane.

(3) Fiber per cent cane equals fiber per cent bagasse times ba gasse per cent cane divided by 100.

(4) Weight of fiber equals fiber per cent bagasse times weight of bagasse divided by 100.

For scheme B, based on the fiber per cent cane* one obtains the follow ing:

(1) Bagasse per cent cane equals 100 times fiber per cent cane* divided by fiber per cent bagasse.

(2) Weight of bagasse equals bagasse per cent cane times weight of cane divided by 100.

(3) Weight of fiber equals fiber per cent cane times weight of cane divided by 100.

(4) Purchase Contract for Bagasse

A summary of the most important items which are usually included in a contract for the purchase of bagasse in Louisiana is given: 20

A m ill that is producing bagasse in any* sizable quantity and is

using it as a fuel, will usually only be interested in selling bagasse

if they can enter into an agreement of sufficiently long term to justify

the expense of modifying its furnaces to use fuels such as oil or gas

rather than bagasse.

The quantity of bagasse which will be bought per year on a bone dry basis is agreed upon with the stipulation that the Buyer will take and pay for* or failing to take* nevertheless pay for* the amount of bagasse agreed upon.

The Seller agrees to deliver to the Buyer the set amount and any additional tons of bagasse available* if the specific amount is requested in writing by July 1 of each year. Since the production of bagasse might vary from year to year* the Seller will not be required to deliver an amount of bagasse in excess of that produced. All the bagasse delivered is weighed by the Buyer and such weight is verified by the Seller on scales mutually agreed upon. This weighing is done as the bagasse is de livered to the Buyer.

The Seller agrees that the bagasse shall be produced from cane containing not more than 1.25$ by weight of bone dry trash* leaves and tops. The standard methods of trash determination are stated. Deductions are made if the trash is above 1.25$.

The weight of bagasse is calculated on a bone dry basis as follows: samples of bagasse are taken from hoppers in the baling plant every half hour. Moisture samples are run by the Buyer every six hours. The average of such determinations made during each day is considered to be the 21 22

average moisture content for the bagasse delivered that day. The Seller purchase price of the bagasse received during the previous calendar month. furnishes the Buyer with the daily percentage of sucrose and other soluble The remainder is due the following Hay 1. solids in the bagasse calculated by standard methods. If this is not The Buyer has the right to bale, pile, treat, and store bagasse on furnished the sucrose and soluble solids is takenas six per cent of the the property of the Seller, and to erect and install on the property any wight of the bagasse. The total wight of fiberthen equals the weight necessary buildings and equipment for conveying, baling, piling, treating, of bagasse delivered minus the amount of trash in excess of 1.25/6 minus storing and shipping, and otherwise handling the bagasse. The property is the moisture, sucrose, and other soluble solids. usually leased at an agreed rate per acre, and is located adjacent to the

When the Celotex Corporation first began to use bagasse the question bagasse delivery point and such transportation as is available. arose as to the price that they would pay for bagasse. Studies of the The Seller delivers the bagasse to the Buyer at the end of the literature and the operating records of Louisiana sugar factories indi conveyor,, which is located so that the Buyer has access for conveying, cated that one ton of 50 per cent moisture bagasse was roughly equivalent baling, loading, and otherwise handling the bagasse. After delivery to to one barrel (42 gallons) of fuel oil or 6 MCF of 1000 Bill per cubic the Buyer at such a point, the bagasse is handled at the Buyer's risk. foot natural gas. The present contracts provide that the sugar factories The Seller supplies the Buyer, at cost, with steam and electric will be paid for each ton of bone dry fiber the money equivalent of 12 MCF ity, Water is furnished, at cost, for fire protection only. The Buyer of 1000 BTII per cubic foot of natural gas or two barrels (84 gallons) of has the right of way over the Seller's property, however, not to the ex fuel oil. In addition, the seller is paid a bonus of $.50 per ton of tent that i t interferes with the Seller's normal operation. bone dry fiber. With natural gas at 16-2/3 cents per MCF of 1000 BTII All improvements made by the Buyer remain his property but he is per cubic foot natural gas, bagasse would be worth $2.50 per bone dry required to remove his equipment within two years after the termination ton. If the price of natural gas changes, the price of bagasse will go of the agreement, up and down accordingly. For a natural gas price change of one cent per The usual clauses involving default due to accident, fire, explo

MCF the bagasse varies accordingly, 16-2/3 cents per ton. sion, flood, windstorm, tornado, riot, strikes, etc. are included. Mo

The agreements arc usually in effect for twenty years from the assignment can be made of the agreement except by previous consent of first deliveries of bagasse unless teminated by either party on one both parties, except mortgaging or as security for indebtedness. year's written notice. If for some reason beyond control, natural gas cannot be supplied,

On the fifteenth day of each month, the Buyer pays 75? of the total the Seller has the right to use sufficient bagasse to operate the sugar 23

m ill.

Nothing in the agreements makes the Seller obligated to operate the sugar mill if it is not advisable to do so. However, if the mill is not operated for the entire season, the Buyer shall have the option of cancelling the agreement.

Any controversy arising out of an agreement is settled by arbi tration in accordance with the Rules of the American Arbitration

Association.

(5) Handling of Bagasse

Due to the low bulk density of bagasse, it is evident that some of the greatest difficulties to be overcome in any utilization scheme are handling and shipping problems. Since bagasse is usually produced for only a few months out of the year (about 65 days in Louisiana-

Table I) storage of the material is necessary in order that a year long supply can be assured for a by-product use.

The density of bagasse as it comes from the mill is about ten pounds per cubic foot. This makes it necessary to compress the bagasse into bales whose density is about 40 #/ft^. The bales, as made, weigh about 250 pounds each, and they average 17" x 21" x 30" in size(^®).

Some work has been done in an attempt to omit the baling operation, and handle bagasse in loose fora^*).

In Louisiana, once the bagasse is baled, it is carried to the storage site which is usually near the m ill. The hazard of fire requires 24

that it be moved to a safe distance* The bales are lifted by a special grab and placed on the pile. The bales are stacked according to a definite pattern so that air may circulate freely through the stack to aid in drying. This is necessary since the heat of reaction of the fermentation of residual sugars to acetic, butyric, and related acids is quite high.

Spontaneous combustion is always a danger if this precaution is not taken.

Boric acid is placed between each layer of bagasse to aid in its preser- vation by preventing the growth of certain fungi. When the stack is complete, it is covered with corrugated iron roofing which can be used from year to year(®®).

The heat of reaction mentioned, aids in driving off a large portion of moisture in the bagasse. In Louisiana, the moisture content is reduced to about 15-25# by the reaction and storage. This heating period also leaves the bagasse relatively sterile so that these stacks can be left for one or more years without serious loss. The normal loss is about

5% of the original fiber. As the bagasse is needed, it is taken from the stacks and shipped to the point of use.

The following price for bagasse as determined by the 1950 season is given by Keller^®).

Purchase Price of Bagasse $2.50/ton B.D. Fiber

Baling, Stacking, and Covering Bagasse in Field $6.00/ton B.D. Fiber

Loading Costs, Storage to Railroad Cars at Point of Origin $0.50/ton B.D. Fiber

Total, f.o.b. at point of origin $9.00/ton B.D. Fiber 26 25

Added to this price would be that of transportation, which would the original cane, the low percentages being for mature cane. be $1.00 to $1.25 per ton per 100 miles. The advantage to be gained by The fiber portion of the bagasse is defined as that part which is any scheme which will reduce the handling, storing, and shipping cost of insoluble in water, This is the constituent which has been the object of bagasse is obvious from those figures. much investigation, The fiber of the cane has two distinct parts: (1)

In one location in South Africa, bagasse is carried by a belt con the true fiber which is found in sections near the rind and in various veyor and loaded directly into tip trucks which take i t a shortdistance sites of vascular bundles throughout the cross section, The individual to the digester charging room. This eliminates much of the expense of fibers will vary in length from one to four millimeters^®), (2) The baling and stacking. Because of the low density, this system is not pith cells or parenchyma is the other constituent, In the cane stalk, economic, except for very short hauls. In this same area, for a haul of the pith is the walls of the storage cells for juices, Plates I , II and

36 miles, the bagasse is baled to increase the payload III show details of a cane s t a l k ^ l The chemical analysis of whole ba

C hristophcrson^ discussed the mechanical handling of bagasse, gasse, fiber and pith were essentially the s a m e ^ ,

The shipping of bagasse is considered by V a s i l 'e r ^ l The handling of M e Bagasse Fiber Pith bagasse, by the Celotex Corporation, is review ed^), Cellulose , 46.00 56,60 55,40 Gums (Xylan, Araban, Galactan) 24,50 26,11 29,30 (6) Composition of Bagasse Fat and Wax 3,45 2,25 3,55 Ash 2,40 1,30 3,02 Lignin 19,95 19,15 22,30 Mill run bagasse produced during the 1953-54 season in Louisiana had Silica 2.00 0,46 2,42 the following average a n a ly s is ^ )* The similarity between whole bagasse, fiber and pith on three samples Pol 3.4$ Moisture 50,1$ of bagasse has been indicated by L athropM , The pith and fiber samples Fiber 44.2?! were obtained from bagasse by fractionating the material in water after These percentages may vary, depending on the milling efficiency, treatment in a hydrapulper, A screen with 0,04 inches diameter holes was type of cane, trash, etc, In some factories the moisture may be as low used in this operation, It was shown that the ratio of pith to fiber in as 40?!, I t will be noted that the three items do not add up to 100$, bagasse is about one to two, Some screen analyses of the separated fiber The other 2.3$ is usually considered to be water soluble material in the are given, In another work, Iath ro p M reported proximate chemical bagasse other than pol, Dextrose and fructose make up most of this. analyses on coanercially baled bagasse from Louisiana, Fiber lengths and Spencer^) has indicated that these sugars make up only 0,4 to 1,35$ of Plate I*10)

m m m , . - - TSJp.fr Q ~ r 'C '

Fig. 17. A oection through the outer part of n cane stem: 1, epidermis; 2, the thick-walled cells which form the rind; 3, 4, vascular bundles of different sites; 5, thick-walled cells or sclerenchyma which give rigidity nnd strength to the stalk; 6, ground tissue or storage cells. After Lowton-Brnin (06). ANNULAR. ELEMENTS LACUNA Ott AIR TUBE •XYLEM VESSEL

SCLERENCHYMA Du, fS-SIEVE TUBE, PHLOEM -COMPANION CELL PARENCHYMA OR STORAGE CELLS INTERCELLULAR SPACES Fig. 20. A diagrammatic drawing of Fig. 19 showing the structure of the vaseular bundle and surrounding storage cells in three dimen sions.

Plate 11^®)' 29

Plate III*10)

Fig. 21. A, tho parenchyma or storage cells in the stalk*are somewhat circular in shnpe when viewed in cross soction. The inter-cellular spaces between the individual cells are also shown in this photograph. B, in longitudinal'sections the storage cells are rectangular in shape. 30

vidths are compared with those of various voods. The pith to fiber ratio is about one to two in bagasse according to Yce Hu^128).

The variations in chemical analyses of bagasse versus maturity were reported by B'drger^2) . As the cane ages, the fiber content increases, the pentosans increase, the lignin decreases, and the ash increases. He reported that the fiber contains sugar-free water of hydration, and that a distinction should be made between the sugar-free water and the sugar- containing water. Analyses were made to show the variation in per cent fiber, pentosans, lignin, nitrogen compounds, and ash for different cane varieties. The hydrate water is between 20 and 25%, Under pressure this goes down considerably. Comparisons were made between the elemental anal ysis of bagasse and various woods. There is no essential difference. He reported that the fiber length and content vary with varieties of cane, but the chemical composition is the same. This may account for success in one place and failure in another in the utilisation of bagasse. B8rgcr also reports that the fiber length in Louisiana is long, but in India it i s very s h o rt (2mm).

The ash in bagasse varies from less than one per cent to more than ten per cent, depending on conditions. Several investigators have reported on the composition of bagasse ash^24^ 89^ 83^ " ) • In all cases, the Si02 content was greater than 70^. The Fe 2<)3 content, which probably gives the ash its red color on occasions, varies widely.

A complete analysis of sugar cane in Louisiana is given by Spencer^3-7).

A report on the fibers in bagasse, and an analysis for pentosans, lignin, cellulose and ash are given by Honig^84). Results of chemical examination 31

of Indian sugar cane bagasse^S) have been reported. A rapid method for

sucrose analysis in bagasse using a high speed blender is reported by

Schm idt^?) #

(7) Bagasse as a Fuel

Bagasse has a bulk density of about ten pounds per cubic foot.

Because of this, its physical volume may become a nuisance and a method

of disposal needed. Fortunately, it makes a good low grade fuel. Fac

tories that produce more bagasse than needed for steam requirements usually operate their furnaces inefficiently to dispose of the excess bagasse. In spite of all the work that has been done to find other uses

for it, approximately 90 per cent of the world's bagasse is burned.

Bagasse is usually carried directly from the mills to the boilers by carriers of the drag type and is fed to the boilers mechanically^?).

According to Millcr(8b) the automatic feeders save labor and improve boiler operation.

W ils o n (H 2 ) states that there is no record of the first grate fur nace used for bagasse but flat grates were used prior to the invention of

the hearth furnace by Stillman in 1856. The step grate furnace was de veloped in the 1890's and soon after 1900 a step grate furnace was produced

to allow the bagasse to dry before being burned. The Ward hearth furnace which appeared in 1936 has the widest use of this type at present. In

1947, the spreader-stoker type of grate furnace was adapted to the burn ing of bagasse. He says that this is considered to be the best grate type furnace for modern m ills. 32

/ 70) Lorenzi' ' states that the older plants used a multiplicity of

small boilers with refractory hearth-type furnaces. The operating ef

ficiencies were low. These older furnaces have been out-moded in the

last ten years by the development of the sprcader-stokcr, water cooled

furnaces, bent tube boilers, superheaters, air heaters and bagacillo re

turn systems. Three stages of burning are discussed by Lorenzi: drying,

distillation and burning. Since 85J5 of the combustibles in bagasse is

volatile matter, much burning takes place away from the bed. He also

states that turbulent suspension burning, which increases the time of

fall of bagasse through the hot gases, is an excellent feature of stoker

firing. The variable speed drum type feeder is considered to be one of

the most important contributions to bagasse stoker firing^®^. Spreader-

stoker firing, including a consideration of feeders, grates, distributors,

design, ashpit, air requirements, etc., is reviewed by Miller^88). The advantages of multiple fuel firing in this type furnace is mentioned. Ef

ficiencies are given for various types of fuel. Puig^) stated that the

spreader-stokcr furnace is needed since the use of bagasse as a source of pulp and other valuable by-products is becoming a reality. An item of utmost importance with this furnace is that the factory has an ideal method for burning bagasse or oil, or both at the same time, with the highest possible efficiency, and without having t‘o make any alterations in design^88).

The efficiencies of bagasse furnaces vary widely, but representa tive figures, as stated by Duce^) are given here. In the stepped grate furnace where bagasse is fired at 45^ moisture, the efficiency is about 33

55/6. If the bagasse is baled and allowed to dry to 12/6 moisture, the ef ficiency is increased to 67 or 68/6. If an economizer and/or air preheater is provided, it goes to 75/6. Certain structural arrangements can bring it up to 80$. This would make it possible to reduce fuel consumption by 30$, leaving bagasse available for other uses.

The heating value of dry bagasse shows great uniformity throughout

the w orld^^. Numerous tests show that moisture free bagasse has a heat ing value of between 8300 and 8400 BTlls per pound. A discussion, with recommendations, of six different formulae used to obtain the heating value of bagasse is given by Perk(95). jn a iatcr article(^), he states that when formulae for the calorific value of bagasse are mentioned, it is not always clearly indicated whether they refer to the higher or the lower calorific values. Moreover, the results of some of them represent neither the higher or lower value. The formulae of Van dcr Horst are strongly recommended.

H.C.V. - 8190 - 18s-8l.9w

L.C.V. = 7650 - 18s-86.4w where: H.C.V. equals higher calorific value; i.e ., where the products of combustion are cooled back to 60*F.

L.C.V. ■ Lower calorific value

s a Sucrose, $ bagasse

w * Moisture, $ bagasse

Basis: H.C.V. of dry ash free fiber in bagasse * 8442

Average Ash content « 3$ 34

W ilson^2) gives the ultimate analysis of bagasse as follows:

Hydrogen, per cent 5 to 6

Carbon, per cent 45 to 47

Oxygen, per cent 45 to 47

Nitrogen, per cent 0.25 to 0.27

Ash, p er cent 1 to 5

Calorific value, dry, 8000 to 8500 BTU/lb.

Ultimate analyses from other sourcesagree well with the above.

Also given by Spencer is the heating value of bagasse available in a boiler as it varies with per cent moisture and per cent excess air. For instance, with a moisture content of 48£, and 50% excess air, the value is 2928 BTU/lb. of bagasse

A chart for calculating equivalent fuel values and costs of ba gasse in relation to other fuels is given by Castrock and Lynch^^.

This plot deals with the calculations involving unit fuel costs, relative calorific values and boiler efficiencies. ' They also state that in

Louisiana bagasse purchases arc largely made on a basis of the following assumed values:

1000 cubic feet of Natural Cas equals 1,000,000 BTUs

1 barrel (42 gallons) fuel oil equals 6,000,000 BTUs

1 ton bone dry bagasse equals 12,000,000 BTUs

Under conditions prevailing in Louisiana, one ton of average quality bagasse has a fuel value equal to 6,000 cubic feet or 1000 BTU per cubic foot of natural gas^®). 0 ne ton of bagasse under average Cuban conditions closely approximates the fuel value of one barrel of crude oil or 1/4 ton 35

of coal, using the same firing conditions'^.

A review of bagasse fuel quality trends and of recent boiler effi

ciency tests are given by McCullock^®^. The economical combustion of

bagasse was studied by Shillington^®). A study of the burning of pith

in Formosa was m ade^^. There was no carry over of unburned pith to

the stack nor ash lodged between the boiler tubes. The burning of pith,

along with whole bagasse, was accomplished. Steam generation and furnaces

in Louisiana factories was reviewed by Lowc^5*) an(j Amold^3^). Utiliza

tion of bagasse as a fuel is discussed by Gilg^5®).

(8) Pulp Production from Bagasse

Because bagasse is available in large quantities, a tremendous amount of work has gone into the study of its possible utilization as a

raw material for the production of pulp and paper. Starting about 1838,

numerous investigators, some serious, others only promoters, have pub

lished hundreds of articles. A review of many of these is given by W cst^^

and Litkenhous(^). It was about 1938 that successful commercial attempts began to materialize for the production of pulp and paper from bagasse(34).

A review of the most serious work establishes a few basic facts about the use of bagasse as a source of pulp and paper(31)(9) .

1. Removal of the pith from bagasse is essential if a high quality product is desired.

2. If the pith is removed, the fiber is an excellent raw material

for pulp and paper.

3. Pith-free fiber'can easily be converted into pulp by any of the 36

ordinary pulping processes or their modifications*

4. The choice of the various processes is largely one of econom ics, a fact which many early investigators did not fully recognize.

Separation of the pith and fiber presents a problem. If the pith t. cells are left in the bagasse, it results in a pulp which is difficult to bleach, and one which will not drain rapidly on the paper machine. The paper is decreased in strength and becomes stiff. Digestion of the pith consumes additional chemicals, yet it yields little pulp. Many mills, feeling that to remove the pith would greatly reduce the yields of pulp did not make the separation and as a result, failed in the attempt to make a salable paper. Inability to insure a steady and sufficient supply of raw material and the small size of the mill usually was a contributing factor to its failure(31).

Research work carried out by the Cellulose Development Corporation shows that, while it is possible to make some bagasse papers in the labo ratory, and even on some types of paper machines, with little or no pith removed, it is at normal production speeds that the non-removal of pith creates difficulties, both in machine operation and in paper quality(m ).

<4. Research on the utilization of pith has been active for many years and continues(4i>). However, the successful operation of a bagasse pulp mill need not be tied to the economics of a large scale pith utilization, since pith may still be burned in the mill boilers, even along with other f u e l s ^ ^ H ^ S ) #

On the following page is a graph which shows the effect of the pith content on pulping and bleaching bagasse. In this graph bagasse was MO. 340. *20 DIETZGEN GRAPH PAPER EUGENE DIETZGEN CO. 20X20 PER INCH M A S * IN u . 9 . a . 38

assumed to have 30$ pith, therefore, 30$ removal means complete removal of the pith; 10$ means removal of 1/3 of the pith, and 20$ means removal of 2/3 of the pith. This work shows that if a strong paper is to be made from bagasse nearly a ll the pith would have to be removed, since the strength increases rapidly from 1/3 removal to complete removal. For in creased yield and decreased bleach consumption, removal of only 1/2 of the pith would be of great benefit. This graph was included in an un p u b lished memorandum by A tch iso n (I?3) .

Various pulping processes are described by A tchison^l). Of the batch type the Soda, Marsoni, Sulfate or Kraft, Sodium Mono-sulfite or

Neutral Sulfite, Acid Sulfite and Mcchano-Chcmical processes are discus sed. Of the continuous processes, the Huguenot, Celdecor-Pomilio, Morley, and Kamyr processes arc discussed. There seems to be disagreement as to whether or not a continuous process offers an overall advantage over a simple batch process. Processes being used for straw pulp can be used on bagasse. The alkaline processes are considered more suitable than th e a c id .

There are a number of m ills scattered over the world which use ba gasse as a raw material for pulp or paper. These mills are located in countries which have low labor costs, high tariff and import or currency restrictions. Some of these m ills are mentioned by Ducc and Tabb^®).

Among these are the W. R. Grace and Company Mill at Paramonga, Peru; the

Taiwan Pulp and Paper Corporation in Formosa; the Cia. de Celulosa de

Filipinas at Bais Central, Oriental Negros; the Rohtas Industries Ltd.,

Dalmianagar, Bihar Province, India; Farbica de Celulosa in Mexico; 39

Refinadora Paulista, S.A., of Sao Paulo, Brazilj and Sir John Hulett and

Sons in Felixton, South Africa. Additional^®)(36) ones are ^hc Ebro

M ill, Argentina, the Container Corporation of America Mill of Cali,

Colombia, and Valentine Pulp and Paper Company at Lockport, Louisiana^**).

At present, m ills are being considered in Egypt, Argentina, Puerto Rico,

Hawaii, Louisiana, Mexico, South Africa, Jamaica, the Dominican Republic,

Cuba, and other cane producing arcas(^).

The Neutral Sulfite process gives high yields when pulping agricul tural residues .and it docs not require a chemical recovery system. This process was investigated by Aronovsky, et al, in the pulping of wheat straw(28). jn a latcr paper(29), he compared the Soda, Kraft, and Mono sulfite pulping of bagasse.

Some of the paper-making characteristics of bagasse arc given by

Bordenare^^). It is basically a short fiber which requires little cut ting treatment during beating. The sheet which is produced will generally be close and firm, with good formation and look-through, coupled with a good Bhandlew. These qualities are especially good for writing papers.

It also has excellent strength properties. A disadvantage is that it is less opaque than some fibers. Its tear factor is low when used for strong wrapping and sack papers. It has excellent rigidity properties which make it suitable for corrugating.

The most successful use in the white range arc writing papers

(where up to 90# bagasse can be readily used) and corrugating paper in the brown range. For most printing papers, it is desirable to add rather more than 10# of other fibers to impart softness. For sack papers and 40

strong wrappers, long fibers must be added to impart tearing stren g th ^).

Blended with other pulps, bagasse pulp has a wide range of uses.

As with straw and esparto, it has also certain distinctive qualities which

make it a definite asset as a paper-making material in its own right, and

not merely as a substitute for another fiber. For example, the short

fibers impart good appearance and strength to fine papers, and the good

sheet-forming characteristics are made use of by mixing bagasse pulp with

wood pulp, thus reducing the amount of beating required for the w o o d ( 4 5 ) .

The optimum conditions for pulping bagasse w ill depend on its pre

vious history(^8)# The amount of chemicals have to be adjusted depending

on the lignin content and the acetyl contents of the particular bagasse.

A Mechano-Chemical process which was developed by Lathrop and

Aronovsky for the pulping of agricultural residues does not require pres

sure digesters and due to its other advantages seems to show great promise.

Atchison(30)(31) discusses this process. Diagrams of the proposed process

arc included. Work^4, 125, 126, 127, 128, 129, 130) Formosa has pro

duced data on the pulping of bagasse by the Calcium Sulfite Process,

Alkaline-Chlorine Process, and Butanol pulping.

It should be emphasized that in all the work which has been done on

the pulping of bagasse, very few careful pilot plant studies have been made on the sep aratio n o f th e p ith from f ib e r. A thorough study on a

pilot plant scale of the separation process, with regard to capacity, power requirements, and efficiency of separation, would be an important contri bution toward making bagasse a more valuable raw material for the production of pulp and paper. 41

(9) Building Board

At the present time various types of building board are being manufactured from bagasse. Celotex is the name applied to the product manufactured in Louisiana, Canex is a similar product being produced in

Hawaii and in Australia it is called Canite. Trinidad bagasse is shipped

to England to be made in to C e l o t e x ^ 1^(49)# Basically, all of these

products arc the same. The Celotex Corporation in Marrero, Louisiana, was the first to successfully manufacture products from bagasse^). The

success of their operation lies in the high yields of product and their

low cost mechanical operation on the bagasse. Also, an inherent property

of bagasse was employed to produce a quality product that is difficult to

produce by other means. An extensive sales promotion program helped.

The process by which the building boards are produced is described by several authors(^)(^)(19)(49)(23) # The essential steps arc:

(a) Preparation of the pulp;

(b) Formation and drying of the board;

The minimum size building board factory to be operated economical ly would be 75,000 square feet (1/211 basis) per day. About 22,000 short tons of bagasse per year would be required for a 100,000 square foot per day mill (30,000,000 square feet per y e a r)^ ). Another important point is the availability of water, and the influence of the pith on water consunption. By present methods of processing, for a bagasse board plant of

150,000 square feet per day of 1/21 board, 400 gallons of water are re quired per minute or twice this quantity if it is necessary to wash out 42

part of the pith and dirt to improve the appearance of the board^9).

Waste paper supplies the hydrated fibers which act as a binder to

the bagasse. A board mill would need an ample supply since about 20 %

waste paper is required. Bagasse pulp could possibly replace this, if

the pith is removed^6) .

It is reported, in 1950, that $1,500,000 should cover the cost of

a 100,000 square foot per day plant. An investment of $2,500,000 would

cover cost and provide working capital^**).

A continuous method for the production of hard board sim ilar to

Masonite is described by A ric s^ ), A study of Celotex was made in

Taiwan by Hu(129) .

(10) Bagasse Plastics

The original research on methods for producing plastic-molding

compounds from lignin containing agricultural residues was done with the

utilization of corn stalks in mind^*^ • The economic advantages of ba

gasse were soon realized and the methods modified. The Valentine Sugar

Company of Louisiana was the first to enter this field, as the Valite

Corporation. The first practical commercial plastic molding compound

was developed by the corporation in 1941. Since that time their resins

have achieved great success in the recording industry, where it has re

placed large quantities of shellacs, previously used in musical records.

Several resins of both the thermo-setting and thermo-plastic type are

now being made by the Valite C orporation^**) (88) # 43

Some important aspects of bagasse plastics^® ) must be considered.

The cost of the equipment for a plant would not run into high figures, but the distance from the potential users is of utmost importance. A research laboratory would be essential to keep abreast of such a new field. Some 34 articles have been written on the subject of bagasse p l a s t i c s (23) according to West. A patent by McElhinney(164) covers the basic process for production of the resins from bagasse. Because of the secrets revealed in the development of plastic from bagasse, in the future the sugar may be the by-product, and not the bagasse^®®). In the United

States, two out of three records in the Jukeboxes come from the cane fields. Even with the success that has been attained in the field of plastics, this use consumes bagasse from one locality only, which is an insignificant amount compared to the total quantity available.

(11) Furfural

Furfural, which is also known by the names of furfurol, furol, and furfuraldehyde has the following formula:

CH : CH. CH: C. CHO

It is a colorless liquid when freshly distilled. Its boiling point is 161.7*C, melting point is -38.7*C, and it has a specific gravity of

1.159. It is inflammable^^*).

Furfural is present in the products obtained by distilling pento san-containing materials such as bagasse, with moderately strong sulfuric acid^® ). The material has numerous uses^®^) (^®). 44

A yield of 13.1/S on oven dry bagasse was reported by Won(122).

Collecting the product immediately after the prescribed temperature (180-

200#F) of digestion was reached instead of after a definite duration seemed

to be all important in obtaining a high yield.

The conmercial production of furfural was discussed^®), its for mation and behavior was investigated by Dunlop^*), and the kinetics of

formation and the stability are considered. The saccharification of agricultural residues was investigated by Dunning and Lathrop(55)# The yields of furfural from bagasse was studied by Jagadish^^, who reported lower figures than those given by Won.

One of the major uses for furfural is the manufacture of adiponi- trile, an intermediate compound used in the production of nylon^®®) . A plant has been constructed in the Dominican Republic to make furfural for this purpose^®).

(12) Cattle Feed from Bagasse

From the chemical viewpoint, bagasse is largely carbohydrate ma terial, built up of the same chemical units, for example, as are grains such as com and barley. In the grains the carbohydrates exist as starch, but in bagasse they occur as cellulose and related compounds. In the ali mentary tract of a ruminant animal, the cellulose is much more resistant to digestion than is starch. Cattle have very little possibility of di gesting cellulose and most of the material is broken down by microbes occurring in the digestive tract of the ruminant(118) .

It is the general concensus from past studies^119) that the main 45 46

difficulty to be overcome in the use of rations high in bagasse is that bagasse has a very low TDK value, 4 method to determine the absorption

of palatability. in inverse relationship existed between the Mount of capacities of pith and certain other feed constituents has been established

bagasse in the ration and the amount tbe animals ate. The replacement of by N a f f iig e r ^ , The pith from bagasse was by far the most absorptive of

final molasses by 'B1 grade molasses in the bagassc-molasscs feeds re any material investigated,

sulted in increased feed intake and gains, but the gains in weight did The great interest in the use of bagasse as a cattle feed has been

not offset the added feed costs. as a potential outlet for the large amount of pith available if the ba

The following analysis of bagasse is given by N o r d f c ld t^ l gasse were separated into its pith and fiber fraction, An economic outlet

for the pith would unquestionably improve the chances for the profitable Type of Bagasse Protein Ether Crude 'Ash N-Frcc Extract Fiber Hatter use of bagasse in paper production. lionsifted dry 1,25 0,39 43,7 2,51 40,1 (13) Miscellaneous Uses of Bagasse Treated with NaOH 0,99 0.28 53,5 2,58 35,6

Rough, Partially decayed 1.53 0,43 46,6 2.48 39,5 There have been many other uses developed for bagasse besides the

Bagasse Pith 0,73 0,31 36,0 2,16 50,8 co*on ones discussed, These do not account for any sizeable quantity of Wheat Straw 3,30 1,50 37,6 4,20 38.4 bagasse,

The manufacture of charcoal or, in general, the destructive dis Wheat straw is chemically treated in Germany and some other European tillatio n of bagasse has been investigated^), In many sugar producing countries to increase its digestibility and nutritional value. It was areas the forests have been practically depleted, and the favorite fuel thought that the same could be done for bagasse. This approach was for many of the people in these areas is charcoal, An account of the tried by N o rd feld t^^ with a degree of success, work that was done in Batavia, Java, in 1941, is given by l l a c r ^ l It toyman, et ai(^0)(l2l)(119) investigated the possibility of using was found that bagasse charcoal was satisfactory when used in the house molasses and bagasse pith as a feed for swine, dairy heifers, milking cows, hold but could not be used as a substitute for coke in the lime kilns, and beef steers. He stated that the only factor on which there has been According to Othmer^), 2000 pounds of bagasse produced 1050 pounds of definite agreement about bagasse in its use as a feed is that it is an charcoal, 1,2 gallons of crude methanol, and 53 pounds of acetic acid, excellent molasses carrier, This has permitted as much as 63$ molasses In addition, combustible gases could be used for heating, Several refer to be added to bagasse in feeding tria ls , Digestion studies indicate that ences on the destructive distillation of bagasse are given by f e t ^ ) . 47

and the use of bagasse carbon as a decolorizing agent is discussed. De colorizing carbon from bagasse was investigated by Shim idu^^. The Indian

Institute of Sugar Technology presented an article on the work they have done on the manufacture of activated carbons^*®®) ^ ^ chloride and a sulfuric acid method are mentioned that use bagasse.

Work done in Hawaii for use of bagasse as an agricultural mulch is discussed by Humbert^^). He stated that in their heavy clay soils 15 to

20 tons of bagasse and cane trash were used per acre. The results were most encouraging, particularly since the rainfall is low and water con servation is of utmost importance. Since bagasse has such a high carbon- nitrogen ratio, six pounds of nitrogen per ton of organic matter were applied to eliminate nitrogen starvation. This amount is said to satisfy the requirements of the micro-organisms and the growing crop.

In Louisiana, the use of bagasse as an animal litte r and agricul tural mulch has met with some success. Servall-Stazdry is an example of a poultry litte r which is produced by Godchaux Sugars, Incorporatcd(159)#

In processing, the bagasse is fed into a rotary gas fired drier. The high temperature used in dehydrating, explodes the cells into a fluffy, resil ient, absorbent, light colored litte r. About 80 pounds will cover a 100 square foot area, 3 inches deep. It will also absorb three times its own weight in moisture. It is said that several factories in Louisiana and one in Florida are producing litter from bagasse^® . Florate, also a Godchaux product(l54 ) f is an example of an agricultural mulch. It is processed much the same as the Servall-Stazdry. It is produced in a fine and coarse grade. The fine grade is used for mixing with soil, making seed beds, 48

mulching lawns* etc. The coarse grade is used for heavy mulching* pack aging of plants* storage of plants* etc. It should be noted that bagasse tends to make soil acid, and the addition of lime is required to produce an alkaline soil. When bagasse is used on growing plants* nitrogen is added* since it is an undecayed organic material. Two leaflets have been published describing these products in more detail(-^)(159) #

Several references by Scott^3-8) discuss the use of bagasse as a compost in Jamaica. The economics were not investigated. The fact that this was a way to get rid of excess bagasse and distillery slops without running afoul of Government regulations was sufficient incentive to use this method. Bagasse compost studies were made in Formosa by Yann^23) .

Nitrogen availability of bagasse compost to wheat and dry land rice is discussed. He also studied the physical and chemical changes of bagasse composts during decomposition.

Some of the other uses for bagasse which have been investigated are the production of fuel oil^3^ )^ 3)* wood sugars^8) (48) (55)(108 ) f glass from bagasse ash(9)(8**), tobacco substitute^83), lightweight con- crcte(58M118)* yeastU?), filter aid(180), and oil well drilling mud. CHAPTER II

EXPERIMENTAL A. EVOLUTION OF THE BAGASSE SEPARATION PLANT

In order to produce a quality pulp and paper from bagasse, separa

tion of the pith fraction, or juice bearing cells, is of prime importance.

A study of existing methods showed them to be impractical or expensive.

After several suggested processes were tried and proven to be unsatis

factory, it was decided to investigate the possibility of separating pith

from bagasse with a laboratory size swing hammer m ill.

The f i r s t attem p t a t se p a ra tio n using a swing hammer m ill was made

in November, 1945. A sample of fresh bagasse was placed in a small swing hammer mill while a jet of water was directed into the m ill. The beating action of the mill loosened the pith particles which were adhering to the

fibers. V/hen this material was placed in water the pith floated and the

fiber sank. A few runs were made on the laboratory size swing hammer mill to determine the feasibility of using this system for the separation of

pith and fiber from bagasse. It showed such promise that a somewhat larger mill was designed at Louisiana State University and built by a manufacturer of swing hammer m ills .

Connected in this new mechanical separation system was a flotation

tank, which was to permit a continuous separation of the fibrous from the non-fibrous material by flotation. This mill minus the flotation tank was very similar to that shown in Plate XXIII.

The bagasse was fed in at the top of this mill and jets of water were directed onto the feed from the side and end of the mill head. The

50 51

a c tio n of th e hammers was to break up th e bagasse in to a f ib e r- p ith mix

ture. Fine material passed through the screen located directly under the

swing hammers. The fibrous material was discharged at one ond of the mill

and dropped into the flotation tank. Here, additional separation took

place since the pith floated arid the fiber sank. The fibers were scraped

from the bottom by a continuous belt conveyor.

The first experimental work on this hammer m ill-flotation arrange ment was conducted during the period from December 1947 to March 1948.

This method of operation provided a continuous means of mechanical sepa

ration. It was found that a relatively clean pith fraction could be

obtained by this system provided the fiber fraction was recycled several

tim es. The r e s u lts (from 13 runs) indicated that from the original ba

gasse about 35/6 fiber (dry basis) could be obtained by this method.

A new type mill head was designed to improve the beating action on

the bagasse. This new’ head contained four water jets located at the end of the mill and seven along one side. The apparatus was much the same as that in Plate XXIII. The series of investigations, undertaken by Linder(^43) in the fall of 1948, showed that fresh bagasse gave better results. After standing several days, tte bagasse would not process satisfactorily in the mill and the resulting mixture, on being discharged, sank to the bottom of the flotation tank. A series of runs were made on this apparatus to de termine the optimum operating conditions. There was no recycle and only one pass of the fiber through the m ill. Part of this data is reported in

Table XIII, and Figures 14, 15 and 16, and will be discussed later. A series of tests using a combination of straight and twisted hammers, was 52

then conducted. The only conclusion from this was that too many twisted hammers did not allow the fiber enough time in the mill and the amount of separation was reduced. It was found later that the particular hammer ar rangement which is used will greatly affect the maximum feed rate attainable.

On a basis of the previous investigations a semi-commercial pilot plant was built in 1949 and was ready two weeks before the end of the 1949 grinding season. This apparatus included three hammer m ills, two flota tion tanks, and a pith and fiber strainer tank. The pith from each mill was combined in the pith strainer tank but all the fiber passed through each of the three mills being discharged into flotation tanks after the first and after the second mill to aid in the separation. On leaving the third mill the fiber was discharged into a fiber strainer tank. Several runs were made on this apparatus before the end of the 1949 season. It was concluded that the plant should operate during the grinding season to process fresh bagasse, the operation should be run at maximum capacity for long periods of time, and the addition of the flotation tanks to the simple milling process was not necessary to effect the desired separation.

The Pilot Plant was then modified into a more compact unit with no flo tation tanks. With this modification, the plant took essentially the form in which it exists today (Figure V, Plates IV, V, VI, VII, VIII and IX).

This new pilot plant was ready at the beginning of the 1950 grind ing season. Various washing procedures using hot and cold water or steam or a combination of these on all three mills were used. It was found that the fiber fraction obtained from this apparatus was only about 32 per cent of the original feed. This work showed that a much simpler apparatus than 53

used in previous seasons could separate bagasse into its pith and fiber

fraction on a continuous basis. However, the yield of fiber was still

disappointingly low.

In the Fall of 1951 several pieces of equipment were added to the apparatus. A feed room was built and a bucket elevator (Figure 5, Plate

XIX) added so that a more even flow rate of bagasse to the Separation

Plant could be maintained. Since bagasse could be stored and weighed in

the feed room, the cane mills did not have to be operating in order to

have bagasse available at a convenient time for processing in the Separa

tion Plant. A pith and fiber product scroll was also added to carry the

products outside the building. The yield of fiber was raised to about 45

per cent of the original feed. Difficulty was still experienced in ob

taining a high feed rate. The screw conveyor was not a satisfactory means

for handling the fiber product. The fiber tended to ball up and vredge under the screw. Difficulty was also had at the hanger straps. Bagasse clogged the screens in each of the m ills, thereby reducing the separation and affecting the results for the percentage separation. Water was in jected into all three mills during this season.

In the Fall of 1952 a product fiber tank was added (Figure 5, Plate

XXI) so that the fiber could be chemically treated and the difficulty with the fiber product scroll eliminated. It was during this grinding season that the author began work on the Bagasse Separation Plant.

There was considerable difficulty in maintaining a steady flow of water to the mills due to the water jets and water lines becoming plugged with pith. The screen in the pith strainer tanks was too coarse (0.050 inch holes) and permitted a large amount of material to pass through into 54

the water which was recirculated to the m ills. (One of the three recir culation pumps is showi in Plate XI.) Use of hot water on the mills aided slightly in the separation. Better processing was obtained with fresh bagasse. The bucket elevator was found to lim it the highest flow rate of bagasse to about 2500 pounds of wet bagasse per hour.

For the operation in the Fall of 1953, a smaller screen size was used on the fiber and pith strainer tanks. Filters were placed in the water lines to each of the mills in an attempt to maintain a constant circula tion rate. These plugged quickly and had to be removed. It was then decided to inject water into the mills from the city water line and dis charge it directly to the sewer from the strainer tanks (November 4, 1953).

This aided tremendously in maintaining steady state conditions in the apparatus. For the first time, information was obtained on the amount of water going to the m ills. Before this, only the makeup water was measured and not the flow to the m ills. A pith discharge chute was installed on the No. 1 mill (D, of Figure 5) so that the pith coming from this mill could be weighed separately. It was found that a large quantity of pith was being removed by this first m ill and that the quality of the fiber product from the No. 3 m ill was not affected by running the No. 1 mill dry. Water was still used on the No. 2 and No. 3 m ills. Some separations were made without the use of water, and some with a combination of steam and water (Table II and Table XVII). Power consumption of individual mills were determined under no load, bagasse feed, bagasse feed plus steam in jection, and bagasse feed plus water injection (Table III) conditions.

The guard bars on the bagasse chute to the bucket elevator were removed 55 56

to obtain higher feed rates to the unit. The highest rate obtained dur vas put on the No, 3 mill, i t vas accidentally connected so that the di ing this season for sustained periods was over 4000 pounds of wet bagasse rection of rotation vas such that the top of the mill moved tovard the per hour. The analyses of the fiber for desirables and undesirables were observer in Plate VIII, When this vas done, the mill choked down com

made during this season's operation (Table XVII), pletely, I t vas observed during this inspection that the No, 1 mill had Samples of bagasse and dry separated and wet separated fiber were a 1/4 inch screen under the hammers and that Hills 2 and 3 each had a sent to the International Paper Company for evaluation (Table XVIII), 1/8 inch screen under the haaners, In the Spring of 1954, pulping experiments vere carried out on dry For the 1954 season, the direction of rotation of the No, 1 and and vet separated fiber, to determine the significant variables, This No, 2 mills vas changed so that the tvisted hammers aided the flov of vas organised so that a statistical .analysis of the data could be made bagasse through the mills, I t vas decided to investigate the effect of (Tables XX, XXI, XXII, and XXIII, and Figure 22), Several determinations various screen sites, two and three mill operation, and the number of vere also made on the previous season's runs for ash in the feed, pith and mills to vhich water vas applied, A by-pass chute (Plate IX, E of Figure fiber, Particle site deterainations vere made only on the fiber, 5) vas installed so that i t could take the fiber from the No, 2 mill and In the Sumner of 1954, when the lids vere removed from the mills of discharge i t into the fiber strainer tank, For the first time, the various The Separation Plant, several facts of importance vere noted, H ill No, 1 runs to be made during the season vere detemined beforehand, and the (Plate IV) had only one twisted hammer per rov, vhich vas on the discharge student groups vere oriented on the conditions to be investigated, Even end, This mill had been rotating so that the tvisted hammer vould tend though the lid of each mill had to be removed several times to change the to hold bagasse in the mill, Referring to Plate IV, the top of the mill screens, more reliable runs vere made during this grinding season than vas moving away from the observer and the bagasse fed across the top of during any previous one, the haaners from right to le f t, For Hill No, 2 (Plate VI) the bagasse On several occasions the Separation Plant vas operated continuously fed from le ft to right and the top of the mill turned tovard the observer, for 5 to 6 hour periods to produce fiber for large scale drying experiments,

Again the 4 tvisted hammers on the discharge end tended to hold the bagasse Because of the indications from ash analyses made the previous year, i t

in the mill, The No, 3 mill (Plate VIII) had 4 tvisted hammers per rov but vas decided to run ash determinations on a ll the runs during this season in this case the mill rotated so that the top of the mill moved away from (Figures 10, 11 and 12, and Tables V, VI, VII, VIII and IX), The per cent the observer, vhich aided the flov of bagasse from right to le ft through solids and the per cent mud in the drain vater from the plant vere checked the mill, During the 1954 season, when the instantaneous power recorder (Figures 17 and 19, and Table XIV), The densities of the fiber and pith 57

under various compressive loads were determined (Figure 20, Table XVI).

Analyses of the particle size of the fiber were made (Figure 19, Table XV).

The power of each individual mill was recorded again (Table III). The water meter was calibrated. Bales of fiber were sent to the Celotex Cor poration for evaluation (Table XIX).

A problem which was viewed concurrent with the development of the

Bagasse Separation Plant was the storing and handling of the bagasse and fibcr(68). it was concluded that if bagasse could be dried by blowing unheated air through it in bulk form, the baling operation might be elim inated, thereby greatly reducing the ultimate cost of bagasse or fiber as a raw material. In the fall of 1953, a drying tower (Figure 6) was built and pressure drop and drying data for air blowing through a column of ba gasse were collected (Figure 21, Page 139). Several columns were designed for experiments on a larger scale. In the fall of 1954 an 8' x 10' x 12' room was used for drying experiments similar to those using the drying tower in Figure 6. These data are reported in Reference 138. B. APPARATUS

(1) Bagasse Separation Plant

(a) Bucket Elevator (Plate XIX)

This is similar to the Link Belt Type 7, continuous type

bucket elevator. The buckets are a V shape, 8 inches long, 6-1/4 inches wide, 5-1/4 inches deep. The elevator is 30 feet high and is driven by

a 1-1/2 horsepower motor.

(b) Main Feeder S c ro ll (P la te XVI and Figure 5)

This is of the continuous screw type. It is a 12 inch screw with a pitch of 11.5 inches and is chain driven by a three horsepower,

56 r.p.m. gear motor. The conveyor turns at 65 r.p.m. and has a linear

speed of about 62 ft./m in.

The feeder to each mill is a short section (18 inches) of an

8 inch screw conveyor with a pitch of 9 inches. The feeders to the No. 1

and No. 3 mills are chain driven by three horsepower gear motors and the

feeder to the No. 2 mill by a 2 horsepower gear motor. The No. 1 and No.

2 feeders turn at 80 r.p.m. and the No, 3 feeder at 68 r.p.m.

(d) Hammer Mills (Plates IV, V, VI, VII, VIII and IX)

Each of these m ills is of the swing hammer type with several

special features of construction. Of most importance is the large space

above the hammers. This construction allows the bagasse to be fed across

58 59

the top of the hammers and discharge without the whole mass being required to go through the screen located directly under the hammers. Only the small particles jarred loose from the bagasse pass through the screen.

These particles consist largely of pith and dirt with very little fiber.

It is possible to place 39 straight hammers in each row on the rotor of the m ill. It can be noted that several of the swing hammers have been twisted to aid the flow of bagasse through the m ill. These allow higher feed rates but are not essential. Mills No. 1 and 2 have one twisted and 37 straight hammers per row; Mill No. 3 has four twisted and 28 or

29 s tr a ig h t hammers per row. The diam eter o f th e r o to r , to th e hammer tips, is 17.5 inches. Mills No. 1 and No. 2 turn at 860 r.p.m.j Mill

No. 3 turns at 1260 r.p.m. The No. 1 mill is driven by a 25 horsepower motor, the No. 2 by a 20 horsepower motor, and the No. 3 by a 15 horse power motor. The tips of the hammers of the No. 1 and No. 2 mills travel at 3940 ft./min. and the No. 3 mill at 5770 ft./min.

(e) Pith and Fiber Strainer Tanks (Plate XX and XXII)

These tanks are essentially slat conveyors, the only difference being that they have a perforated screen (0.032 inch holes) on which the slats ride. The purpose of these tanks is to allow time for excess water to drain from the fiber and pith when water is used on any of the m ills.

The slats in both tanks are driven by the same 3 horsepower, 56 r.p.m. gear motor at a linear speed of 140 feet per minute.

(f) Fiber Product Tank and Pith Discharge Scroll (Plate XXI)

The fiber product tank is a slat type conveyor, driven by a

3 horsepower, 56 r.p.m. gear motor at a linear speed of about 5 ft./m in. 60

This tank is deep enough to treat the fiber from the separator with pre servatives, rinse it with water, etc. It discharges the product outside the building.

The pith discharge scroll is a 12 inch continuous screw type con veyor with a pitch of 13 inches and is driven directly by a 65 RPM, 3 horsepower gear motor. The purpose for this scroll is to discharge the pith outside the building onto a draining screen (0.050 inch holes),

(2) The Small Haracr Mill (Plates XXIII, XXIV and XXV)

The small hammer mill is a separate unit from the previously dis cussed m ills. It has 12 straight or twisted hammers per row and is provided with a 1/4 inch screen. The diameter of the rotor, to the haoner tips is

13-1/2 inches. This rotor turns 1700 RPM and is belt driven by a three horsepower, 1160 RPM motor.

The feed to this mill enters from the top at one end and discharges on the opposite end. This m ill has a sloping head and does not have a dam next to the rotor on the discharge end as do the larger mills, previously m entioned.

(3) Rotary Digester (Plate XXVI)

This digester consists of a stainless steel, cylindrical container mounted on bearings so that it can be rotated and heated. A 1/8 horse power, 1725 RPM motor is geared down so that the container turns abont

100 RPM. The container is heated by three standard bunsen burners mounted on a manifold. The inside diameter of the vessel is 6-1/16 inches; 61

the depth is 11 inches. The wall thickness is 1/4 inch and the flange and top are 1/2 inch thick. A Weston thermometer is located in the top to indicate the operating temperature. A needle valve in the top is used for venting the non-condcnsables and reducing the pressure at the end of a cooking cycle.

(4) Drying Tower (Figure 6)

The drying tower is constructed from a piece of 5.5 inch i.d. glass pipe, five feet high. An orifice of 1/8 inch diameter and a mercury man ometer is mounted in the air line to determine the flow rate of air. A water manometer is mounted in the base for determining pressure drop through the tower. A small piece of screen with 0.050 inch holes is at the bottom of the glass pipe to prevent the fibrous materials from falling into the air chamber. Knives

Knives

Crushers Sugarcane 3rd Hill 2nd m i 1st Hill

17a te r n I~nn~ ri

I Juice k Juic9 to Process 4 2nd ! H asser w ater i Hill Water

Eagasse f ib e r

S tra in e r Tank F iber

P ith P ith S tra in e r Thnk F igure No. U Flow Sheet for Production of Pith and Fiber Audubon Sugar Factory, Louisiana State University, Baton Rouge, Louisiana

cr> Dravm by R. II. Hansen to Date - Feb. 18, 1955 63 Ducket j E le v a to r I/o tor

w ater .'so (i i ’ ') \ I ' Main Feeder S c ro ll VI r - T Ho. 1 /U Hammor M ill , i „ y T W U r

a ,. Motor A-Feodor Scrolls B-Fiber Chuton C-Pith Chutes D-Pith from No.l yJWw , tmsr m ill l/'i / No. 2 E -F ibor from Mo.2 ] Hammor M il m ill, By-pass Motor F-Stra.lnor tanks G-Inspoct.ion Door Mo to r

No. 3 Hammor Motor

Motor

■f Water •(' Meter

F ig u re No. 5 Bagasse Separation Plaht ./ Audubon Sugar Factory F ib er / . ' iDrain Louisiana State University Water Baton Rouge, Louisiana Drawn by: R. M. Hanson Date: Feb. 17, 1955 Pith Discharge Scrol Motor / Fiber Product . Tank P la te IV, H ill No. 1 , Lid Removed Plate V, Mill No. 1, Assembled

Plate VI, Mill No. 2, Lid Removed Plate VII, Hill No. 2, Assembled r

i _

ft*0 3 Plate VIII. Mill No. 3, Lid Removed Plate IX, Mill No. 3, Assembled and By Pass Chute 65

Plate X, Control Panel, Bagasse Separation Plant

Plate XI, Water Meter and Valves, Recirculation Pump

Plate Xll, Spencer Rotary Plate XIII, Moisture Tellers D ig e ste r

Plate XIV, Ash Analysis Apparatus, Plate XV, Saccharimeter Small Moisture Teller P la te XVI, Main Plate XVII, No. 3 Feeder Scroll Feeder Scroll P la te X V III, No. 2 Feeder Scroll r

Plate XX, Fiber Strainer Tank

Plate XIX, Bucket Elevator

r Plate XXI, Pith Discharge Scroll, Plate XXII, Fiber and Pith Fiber Product Tank Strainer Tanks, Plan View 67

Plate XXIII, Snail Hammer M ill, Assembled

P la te XXIV, Sm all Haxmner M ill, Lid Removed

Plate XXV, Inside View of Lid with Sloping Inset

Plate XXVII, Method of Pulp Washing P la te XXVI, E xperim ental D ig e ste r for Pulping Plate XXVIII, Raw Bagasse Feed to Bagasse Separation Plant

P la te XXIX, F ib er P roduct

Plate XXX, Pith Fraction 69

S .# Glass Tube High

Scroon, 0.0£0 inch holes. L 1/6 inch *~Orif ic e Compresaa'd. t h S ta tic A ir P ressure Water o- Manomotor

Figure No. 6

Bagasse Drying Tower Chemical Eng* Department Louisiana State University Drawn by* R. M. Hansen Mercury Date: Feb. 20, 19# Manometer C. OPERATION OF THE BAGASSE SEPARATION PLANT

The bagasse used in the separation unit was obtained fro* the mill in the Audubon Sugar Factory. From Figure 4, one nay see that the sugar cane first passes through two sets of rotating knives to reduce its bulk*

It then passes through a two-roller crusher and 3 three-roller m ills.

From the last m ill the bagasse falls into a slat conveyor. This con veyor can either deliver the bagasse directly to the bagasse separation unit or to a storage room.

For a ll the test runs the bagasse was delivered to the storage roost so that it oould be weighed on a platform scale, and a closer control kept on the feed rate to the separator. Here, too, samples were taken for analyses. The scale used for weighing the bagasse was calibrated at the beg in ning of each grinding season and also spot checked before each run.

Bagasse produced during the morning was used that same afternoon in the

Bagasse Separation Plant.

While the bagasse was being weighed, a thorough check was made of the apparatus to see that no bagasse had accumulated at any point from the previous run, and that a ll of the equipment was in running order. Sample containers were prepared, data sheets marked, and final instructions given to all personnel.

One person and a helper were required to feed the bagasse into the bucket elevator from the storage room. This was an important position since a constant feed rate had to be maintained, and a close watch kept

70 71

to prevent the bucket elevator feed chute from becoming choked. Some dif ficulty was experienced on both of these points. One person vas required to watch the discharge of the bucket elevator, the main feeder scroll, the feeder scroll to the No. 1 mill, the fiber chutes, and to signal the operator on the first floor to shut down in case of difficulty. Some trouble vas experienced with the bagasse accumulating at the various points mentioned. If the bagasse vas veil disintegrated, very few stoppages were encountered. When operating at the extreme capacity of the apparatus, one had to be especially vigilant at the position on top of the apparatus.

One person vas required at the pith chute of the No. 1 mill on the ground floor to catch this fine material in a wheel barrow for weighing. When only two mills vere used, one person vas stationed at the fiber by-pass chute and one other person vas needed on the ground floor to be near the control panel. He also helped the man collecting the pith; watched the water rate, the fiber product and pith coming from the apparatus; collected data; and took samples when necessary. One person vas needed in the labo ratory to do the analytical work. Depending on the type of run, from five to seven persons were needed for the operation.

With the group in their respective positions, the plant vas started.

This vas done by starting the last piece of equipment in the unit first, so that if any bagasse had remained in the mills from the previous run, it would not accumulate at one point before the following apparatus could be started (Control Panel, Plate X).

The following order vas used for starting:

1. Fiber Product Tank 72

2. Pith Discharge Scroll

3. Pith and Fiber Strainer Tanks

4. No. 3 Hamer H ill

5. No. 3 Feeder Scroll

6. No. 2 Hamer M ill

7. No. 2 Feeder Scroll

8. No. 1 Hamer M ill

9. No. 1 Feeder Scroll

10. Main Feeder Scroll

11. Bucket Elevator

As soon as everything was running, the signal was given to start feeding the bucket elevator. At this moment, the water was turned on, i f required; the water neter reading, the time, and the KWH meter reading were recorded. The strip chart recorder for individual mill power demand was started.

From the bucket elevator, the bagasse was discharged into the main feeder scroll (Refer to Figure 5). The scroll could also accept bagasse directly from the bagasse conveyor. From the main feeder scroll, the ba gasse dropped into the No. 1 feeder scroll, and passed from there into the

No. 1 h&mer m ill. The bagasse fed across the top of the hammers in this m ill, being combed by them as it progressed. The small pith particles, dirt, and a small amount of fiber passed through the screen in this mill and vere collected in wheelbarrows on the ground floor for weighing. Water was seldom used in this m ill. When the fiber reached the end of this mill, it dropped into the No. 2 feeder scroll vhich fed it into the No. 2 mill. 73

Here again the bagasse was subjected to the combing action of the haimers and the loosened pith particles passed through the screen directly under the hamners and into the pith strainer-tank. Water was injected into this mill on some runs. Occasionally the fiber was discharged directly from this mill to the fiber strainer-tank without going through the third m ill.

If the third mill were used, the fiber dropped into the No. 3 feeder scroll and then passed into the No. 3 m ill. The pith from this mill also dropped into the pith strainer tank and the fiber was discharged into the fiber strainer-tank. Water vas occasionally used on the No. 3 m ill. In the strainer-tanks, the excess water was drained from the pith and fiber as they were conveyed to the pith discharge scroll and fiber product tank.

Samples of this drain water were taken during the run. In the discharge scroll and the product tank, the pith and fiber were carried outside the building and discharged in piles. From these piles periodic samples were taken for analyses. When all the bagasse had been fed to the bucket eleva tor, a signal was given. Then as the last of the fiber emerged from the strainer-tanks, the water meter reading, the time, and the KWH reading were taken. The apparatus was stopped in the reverse order from which it was s ta rte d . 0. PROCEDWS FOR PULPING

The fiber samples used in the pulping experiments vere stored for about three Booths froa the tiae they vere produced. To get a homogeneous

■oisture content, both the dry and vet separated fiber bales vere broken up, thoroughly nixed, and then placed in large galvanized cans. After several days it vas found that the aoisture content reaained fairly con stant at about 20%, The pulping m s vere then started.

Iaaediately before a run, the moisture content on a 50 gram sample of fiber vas determined. (Apparatus a t right of Plate XIV.) The momt necessary to obtain 200 grams of dry fiber vas then charged into the di gester (Plate XXVI). The amount of vater needed, less that charged with

the fiber, to obtain the proper vater/fiber ratio vas then determined.

When the proper quantity o f sodium su lfite and sodium carbonate had been dissolved in the vater, it vas added to the digester. The top vas then bolted on, the digester placed in the turning jig, and the bunsen burners lighted. When a temperature of 250*F vas reached, the flames were reduced and erne end of a hose attached to the needle valve in the top, the other end vas immrsed in about 500 ml of vater in a 1000 ml graduate. The valve vas then opened and the non-condensable* allowed to blow o ff. I t vas found that when 30 ml o f steam had been condensed practically a l l the nom-condensables were out of the digester. The valve was then closed and the vessel brought up to operating temperature as rapidly as possible. The

74 75

ressel could be raised from room temperature to operating temperature in about 40 minutes. After the prescribed period of digestion at the proper tenperature, the vessel was stopped, the valve opened, and vater sprayed on it in order to reduce the temperature (Typical Temperature versus Time

Curve, Figure 22). The top vas removed and the pulp rinsed (Plate XXVII)•

It was placed in a cloth sack which was tied over a water spigot and sus pended in a bucket of water. After rinsing in this position over night, the pulp was placed on aluainum foil and left to dry for several days. It vas then placed in stainless steel beakers and covered with two layers of foil to obtain an even distribution of moisture. After several days, samples of pulp were taken, moisture analyses run, and the yield calculated on the basis of the dry fiber charged.

The Permanganate Numbers reported in Table XXI were run according to Tappi Standard T 214 m-50 (Reference 140). E. ANALYSES

The following analyses were made on the bagasse, fiber and pith:

(1) Moisture in Bagasse

For noistures in the range of 50 per cent, a sample of 100 grams was used; for moistures of the wet fiber and pith in the range of 80£, a sample of 200 grams was used. They were dried in a Dietert Electric

Moisture Teller (Plate XIII) in which the air passed over electric heat ers and through the bagasse. The maximum drying time that could be set automatically was 15 minutes. The 50£ moisture samples were dried for

30 minutes and the wetter samples were dried for 45 minutes at about

110*C. No change in weight could be detected by drying the samples for a longer period of time.

(2) Sucrose in Bagasse

A Spencer (Plate H I and XV) digester and saccharimeter were used in this determination (Figure 194 of Reference 17). A detailed discussion of the procedure is given on page 568 of this reference.

(3) Soluble Solids in Bagasse

Two methods were used for th is determination.

The f ir s t method was that of running hot water over a weighed sample of bagasse in a 100 mesh sieve. After 30 minutes the fiber was dried and weighed and the per cent solubles plus moisture calculated.

The second method was to use the sample o f bagasse from the deter mination of the sucrose. The bagasse vas drained and one liter of distilled

76 77

water added. It vas again digested for 30 minutes. After this, the fiber vas poured into a 100 mesh sieve, allowed to drain, and then dried in an oven over night at I10aC. The loss in weight of the bagasse vas assumed to be the moisture plus the soluble solids.

(4) Ash (Plate XIV)

The ash vas determined by weighing about five grams of material, on a dry basis, into a tared silica dish, about four inches in diameter.

The dish vas then covered and placed in a "dutch oven" to drive off most of the volatile matter. At this point, the cover vas removed and a large part of the carbon burned. The dish was then placed in an electric muffle furnace at about 600*C to complete the ashing. About 45 minutes vas re quired in the "dutch oven" and about 30 minutes in the electric furnace.

The furnace vas thermostatically controlled but the "dutch oven" vas heated by a Mekcr burner and the only control vas that of adjusting the flow of gas. On the completion of the ashing, the sample vas cooled in a desiccator and weighed. Knowing the original moisture and the weights, the per cent ash vas calculated.

This method vas checked by running numerous samples of the same material. The reproducibility vas considered to be as good as the homo geneity of the sample, (hie determination vas sufficient for the fiber product, but two or three were necessary for the raw bagasse.

(5) Density Measurements

Density measurements were determined by use o f a 3/4 inch thick ply wood box, 31-3/8 inches long, 31-1/4 inches wide, and 32-1/4 inches deep.

The box vas filled with fiber or pith and weighed, and the density of the 78

material on both a dry and vet basis vas calculated. The densities of the

materials under various compressive loads vere also determined. This vas

done by use of a 1-1/2 inch thick top vhich vas fitted inside the box. As

many as 6 persons stood on this top, providing approximately 900 pounds of

weight on a 6.8 square foot surface. The volume occupied by the fiber or

pith was then determined by averaging the distances from each of the corners

of the lid to the top edge of the box. Knowing the weight and volume the

d en sities were then calculated.

(6) Mud in the Drain Water

This vas determined by pouring a freshly stirred sample of the vater

from the strainer tanks into a 1,000 ml. graduate. The solids were allowed

to settle over night and the volume of mud then read on the graduate. The

volume per cent mud in the drain water vas then calculated.

(7) Solids in Drain Vater I A freshly stirred sample of the vater from the strainer tanks vas

poured into a tared 250 ml. beaker. This vas then placed in an oven at

110aC overnight. The beaker was then removed, cooled in a desiccator, and

weighed. The per cent solids vas calculated.

(8) Particle Site Distribution of Fiber

This vas accomplished by taking approximately five grams of dried

fiber and separating each particle into a size range according to its

length. The breakdown of sizes used vas 0 - 1/2: 1/2 - 1; 1 - 1-1/2;

1-1/2 - 2; 2 - 2-1/2; and over 2-1/2 inches. All the fibers greater than

1/2 inch were actually picked up with a pair of tweezers, and their length measured. They vere put in the appropriate group. When a ll the sample was 79

separated, each group vas weighed and the percentages calculated.

(9) Desirables and Undesirables in Fiber

An attempt vas made to measure the undesirables in the fiber by separation vith a pair of tweezers. The desirables vere considered to be fiber particles vhich vere pith free or those vhich had very little pith clinging to them. The undesirables vere considered to be essen tially pith particles or fiber particles vhich had a very large amount of pith clinging to them. This analysis vas reproducible but is ques tionable since it is not a positive separation into pith and fiber. F. IDENTIFICATION OF TEST RUNS

To aid in the identification of the various runs mentioned in the

following tables the code system listed below is used.

An example:

For the data used in Table XIII and plotted in Figures 14, 15 and

16, a typical run is denoted as 48-L-20-A. This means that 1948 vas the

grinding season in which these data wore taken hy Linder(l43)# jhe "20"

denotes the particular run during the season and the A, B or C indicates

h ig h , medium and low flow ra te s of bagasse.

All other data included in this report were taken during or after

the 1952 grinding season under the supervision of the author. For these

runs the prefix 52, 53 or 54 denotes the year; the R, H, M. F and C repre

sents the name of the group leaders, Rogers, Halbrook, McCombs, Frantz

and Colvin. The reports in which these groups listed their data are in

cluded in the bibliography under the group leader's name. The last nuaber

given is the particular run number that the group made. For example,

53-M-13 would mean data taken during the 1953 season, on the 13th run of

McCombs1 group.

The reason for identifying the data by year is that, because of various changes made in the plant, as noted in the section "Evolution of the Bagasse Separation Plant", the data which were collected during one season is not necessarily comparable with that taken at a later date.

80 TABLE I I

DATA FOR POWER CONSUMPTION AND FEES RATES OF THE BAGASSE SEPARATION PLANT

Moisture in „ Vet Feed Rate KWH lbs H2O KWH Feed. % Solubles lb/hr hr. hr" x 10 lb. wet feed

L-l 51 3 1000 27.0 .0288 2 46 6 2500 23.1 .0092 3 47 5 1590 26.0 .0164 4 55 6 1875 25.9 .0138 5 49 6 1945 25.8 .0132 6 49 6 1997 25.2 •0128 7 48 5 1707 24.0 .0140 8 46 6 1810 27.0 .0149 9 46 6 1690 24.5 .0145 1 0 50 6 1650 25.2 .0152 11 49 6 1780 25.1 .0140 Sucrose, % E-4 50 2.7 2320 26.4 12.6 .0125 5 50 2.3 3030 22.5 10.3 .0076 6 57 4.0 3390 21.7 7.6 .0075 7 53 4.8 3100 27.4 — •0093 8 50 4.1 3300 26.8 7.6 .0076 9 48 3.9 3050 24.0 12.9 .0074 1 0 51 4 .1 3770 25.8 27.8 .0069

M 49 3.3 2190 24.9 3.9 .0014 5 50 4.7 2710 25.7 4.5 .0095 6 50 5.5 2880 27.0 17.8 .0094 7 50 4.3 3040 21.9 19.4 .0072 8 52 3.6 3220 25.7 4.6 .0080 9 46 2.8 3320 25.2 22.6 •0076 10 49 4.3 3410 25.2 20.2 •0074 11 50 3.8 3550 30.0 27.3 .0084 12 51 4 .9 3600 24.0 28.0 .0066 (Continued on next page) TABLE I I (Continued)

KWH Rim No, Moisture in Vet Feed Sate lb s H20 i KWH Feed, % Sucrose, % lb s/h r. hr. x 1 0 lb. tret feed

54-H-13 58 3.2 4290 24.9 20.7 .0058

S4-F-1 56 4.1 2470 27.4 14.9 .0111 2 53 2.2 2480 16.8 18.6 . •0073 3 51 3.8 2460 18.0 0 .0 .0073 4 50 2.7 2540 18.0 14.2 .0071 5 52 2.7 2680 18.5 11.4 •0069 6 51 3.5 2780 22.0 17.6 .0082 7 54 5.0 3070 18.0 10.6 •0056 8 53 3.3 3730 18.3 17.7 .0065 9 50 3.1 2650 16.2 0.0 •0061 10 52 3.0 2940 23.2 — .0079 11 51 3.3 3620 23.4 12.6 .0065 12 50 4.3 2490 14.5 5.2 •0058 13 51 4.1 3030 23.2 0 .0 •0076 14 52 3.8 3510 17.6 0.0 .0050 15 52 3.3 2540 24.0 14.5 .0094 16 48 4.0 2190 23.2 21*5 .0106 17 50 2.9 3100 17.1 0 .0 .0055

54-C-2 52 4.1 2450 24.0 7.9 •0098 3 52 - 2220 24.4 5.0 •0100 5 51 3.9 2410 23.9 18.7 .0099 6 49 • 3390 26.8 15.1 .0079 7 46 4 .1 2265 22.0 0 .0 .0097 8 53 2.0 2730 17.0 14.6 •0062 9 50 3.0 3020 23.5 7.5 .0078 10 48 4 .2 2490 23.7 7.1 .0095 11 54 5.0 2680 17.3 10.3 .0064 13 52 4.8 2465 17.7 18.1 .0072 14 50 5.2 2160 23.6 18.8 .0011 83

TABLE I II

INSTANTANEOUS POWER CONSUMPTION FOR INDIVIDUAL HAMMER MILLS OF THE BAGASSE SEPARATION PLANT

Mill Condition

Idle Dry Steam Water

Halbrook 0.9 2.5 4.8 8.7

McCombs

M ill 1 0 .6 2.4 8.2

M ill 2 0 .6 3.0 5.6 11.0

M ill 3 1.4 2.0 4.0 7 .0 (Running in Reverse) Frantz

M ill 1 2.8 2.8 2.8

M ill 2 10.4 9 .2 11.6

M ill 3 16.8

Average 0.9 2.5 4.8 8.7 84

TABLE IV

LOAD FACTOR ON HAMMER MILLS AND ACCESSORIES OF THE BAGASSE SEPARATION PLANT

(A) Total HP Rating of a ll Motors, Connected Load

Manner M ills - 60.0 HP

Accessories 21.5 HP

Total 81.5 HP

(B) Actual Load Running Idle

Ifn—rr M ills only - 15.5 KWH/hr.

Accessories only 9.5 KWH/hr.

Total 25.0 KWH/hr.

Basis: 1 KW - 1.341 HP

Manner M ills

15.5 x 1.341 - 20.8 HP

20.8 60 x 100 a 34.6£ of total notor ratings of nills

Accessories 9.5 x 1.341 * 12.7 HP

12 7 x 100 ■ 59.1% of total notor ratings of accessories 85

TABLE V

ASH ANALYSES OF FEED AND FIBER PRODUCT FOR DRY OPERATION OF THE BAGASSE SEPARATION PLANT

Run % Ash, % Ash, Fiber % Ash, Fiber Number Bagasse Wet O peration Dry Separation

53-M-14 6.80 1.63 2.49

54-F -l 2.8 b 1.52 2.54

2 2.59 1.46 2.33

3 5.27 2 .1 0 3.59

5 10.09 4.03 6.83

6 b.15 1.69 5.35

Averages 5.39 2.1b 4.13

54-F-9 4.99 3.17

13 5.b2 2.50

14 4.84 2.73

17 2.63 2.49

54-C -l 3.68 2.51

7 13.60 b.10

Averages 5.89 3.25 6 6

TABLE VI

ASH ANALYSES OF FEED AND FIBER PRODUCT FOR WET OPERATION OF THE BAGASSE SEPARATION PLANT

Lbs. Vater Lbs. Vater % Ash in % Ash in Run No. t Lb ash in feed x 10 Lb. dry ieed Feed Fiber 53-H-8 1.10 4.6 4.14 1.79 9 1.82 8.5 4.65 1.26 10 1.23 15.1 12.22 2.27

53-M-6 5.45 12.3 2.26 0.86 7 3.89 12.7 3.26 1.12 11 3.41 15.4 4.51 1.31 14 1.95 13.3 6.84 1.63

54-C-2 1.48 6.7 4.58 2.11 5 2.04 15.9 7.80 2.14 6 1.34 8.7 6.50 2.21 8 0.78 11.4 14.60 3.20 9 0.68 4.1 6.20 2.60 10 0.86 5.3 6.15 1.81 U 3.30 8.4 2.73 1.36 12 4.15 11.2 2.70 1.24 13 6.55 15.1 2.31 1.13 14 8.70 17.6 2.02 1.21

54-F-l 4.72 13.5 2.86 1.52 2 6.17 16.0 2.59 1.46 4 4.08 11.2 2.75 1.81 5 0.82 8.2 10.09 4.03 6 2.12 13.0 6.15 1.69 7 2.56 7 .3 2.74 2.47 8 2.38 10.1 4.25 2.02 10 4.29 1.70 11 1.10 7.2 6.47 2.06 12 1.60 4 .2 2.61 1.76 15 4.92 12.0 2.44 1.43 16 10.70 18.8 1.74 0.87

Averages 3.21 10.8 4.91 1.80 TABLE VII

ASH ANALYSES OF FIBER AND PITH FROM EACH MILL OF THE BAGASSE SEPARATION PLANT

Ash analyses, per cent, Run 53-M-ll

Bagasse Feed 4.51

Fiber, Mill No. 1, *dry" 2.98

Fiber, M ill No. 2, "wet" 1.60

Fiber, Mill No. 3, "wet" 1.31

Pith Ash Analyses, per cent

Pith, Mill No. 1 9.05

P ith , M ills No. 2 and No. 3 combined 3.69 CONDITION OF MILLS 3 o Used Not #3 1 l Dry ill M >1 Dry ill M #2 2 l Dry ill M #2 Dry ill M i # 2 l Vet ill M #2 Dry ill M #1 Dry ill M #3 O E Te rst nne of ah et to aus h pr et s i h bgse ed te eod nuober second the feed, bagasse the in ash cent per the s i values two f o t se each f o nunber t s ir f The NOTE: #1 M ill ill M #1 3 o Used Not #3 1 l Dry ill M #1 vrgs | Averages Vet ill M #3 Vet ill M #2 # 2 l Dry ill M #2 Mil Vet ill M 3 SUMMARY OF PER CENT ASH THE IN BAGASSE FEED AND PER CENT ASH FIBER IN PRODUCT FOR VARIOUS OPERATING Dry Dry h pr et s i h fbr Ec set f aus r fr fee runs. t ifferen d for are values of t e s Each fiber* the in ash cent per the s i

#2 M ill 1 /8* Screen /8* 1 ill M #2 3 l 1/ 11 /8 Screen 1 ill M #3 #1 M ill 1/6" Screen 1/6" ill M #1 00 - 6.83 - 10.09 00 - 4.03 - 10.09 .9 2.33 - 3*59 2.59 - 5.27 .8 2.51 - 3.68 .9 1.46 - 2.59 2.54 - 2.86 .5 5.35 - 6.15 .5 1.81 - 2.75 .8 2.11 - 4.58 .7 2.10 - 5.27 .0 2.14 - 7.80 .9 2.61 - 5.49 1.52 - 2.86 .5 1.69 - 6.15

CONDITIONS OF THE BAGASSE SEPARATION PLANT #2 M ill 1/8* Screen 1/8* ill Screen M #2 3/16" ill M #1 #3 M ill 1/8 ** 1/8 Screen ill M #3 44 - 3.20 - 14.40 36 - - 13.60 .9 3.17 - 4.99 97- 24[ .1 1.75 - 3.91 [ 4 .2 -2 7 .9 3 4.29 4.29 .0 2.21 - 6.50 .0 2.60 - 6.20 .5 2.02 - 4.25 - 6 1.70 .I 0 AL VIII TABLE V

SCRE&I SIZES

#2 M ill ill Screen M #2 3/16* ill M #1 #3 M ill 1/8* Screen 1/8* ill M #3 .4 .326 - 2.49 - 2.63 2.73 - 4.84 .2 2.50 - 5.62 .3 1.36 - 2.73 .1 1.76 - 2.51 .0 1.24 - 2.70 .7 2.06 - 6.47 .4 0.87 - 1.74 2.44 .5 1.81 - 6.15 3/lb*. - 1.43

Screen

#3 M ill 1/8* Screen 1/8* ill M #3 1/8** Screen ill M "Screen #2 1/d ill M #1 22 - 2.27 - 12.22 .0 2.49 - 6.80 .5 1.26 - 4.65 4.14 4.14 3 i . l - l .3 2 4.51 4.51 1.21 - 2.02 .1 1.67 - 3.81 6.84 2.26 2.26 3.26 3.26 - - - - - 1.31 1.12 0.86 1.79 1.63

Averages 3.55 5.76 5.00 1.77 g 89

TABUS IX

ANALYSES OF BAGASSE AND FIBER ASH FOR Si02 and F e ^

A Sanpic o f feed and product ash fro® run 53-M-6 vas examined for S i0 2 and Fe203*

Bagasse Feed Fiber Product Per Cent Reduction

Ash 2.26$ 0.86# 62$

Si02 66.45$ 57.12$ 14$

Fe203 1.27$ 0.71$ 44$

This run was vith Mill No* 1, dry; Mills No* 2 and No. 3, with vater* The feed rate vas 2880 pounds of vet bagasse per hour; the vater ra te, 17,800 pounds per hour. There vas a 1/4 inch screen in the f ir s t mill and a 1/8 inch screen in the second and third mills* 90

TABLE X

PER CENT OF FEED RH-iOVED AS PITH FROM THE NO. 1 MILL ONLY, (DRY BASIS)

Hi Mill, 1/8 * Screen //I Mill, 3/16" Screen HI Mill, 1/4" Screen

13 21 19 23

12 2(3 24

14 21 18 24

12 20 24

17 20 22

12 22 20 34

13 18 18

18 21 22

17 20______20 ___

Avg. 14 21 27 CONDITION OF HILLS 3 o Used Mot #3 3 l Vet ill M #3 Dry ill M #2 Dry ill M #2 2 l Dy0.23 Dry ill M #2 Used Not #3 Vet ill M Dry #2 ill M l J Dry ill M #1 3 l Vet ill M #3 . hs fgrs o icue i vrgs r nlss vrac. ah au is fr sprt rn n is i and run separate a for s i value Each variance. t a analysis or averages in included not figures These A. 1 l Dry ill M #1 Dry ill M #1 2 l Vet ill M #2 Averages 3 l Dry ill M #3 H l Dry ill M qa t oa l of .. t . ith p B.D. f o , s lb Total to equal #2 M ill 1 /8 * Screen * /8 1 ill M #2 #1 M ill 1/8" Screen 1/8" ill M #1 #3 M ill 1/8 * Screen * 1/8 ill M #3 oa l of .. aas feed bagasse B.D. f o . s lb Total 0.31 .403 0.39 0.40 0.34 0.29 0.28 0.24 0.27 0.22 0.16 0.39 0.37 0.28 FRACTION OF BAGASSE FEED REMOVED PITH AS FROM ALL MILLS (DRY BASIS)

3 l 18"Screen " 1/8 ill M #3 #2 M ill 1/8" Screen 1/8" ill M #2 §1 M ill 3/16" Screen 3/16" ill M .30.38 0.26 6.32 0.33 0.24 0.40 0.33 0.34 0.35 SCREEN SIZES TABLE XI

#3 M ill 1 /8 * Screen * /8 1 ill Screen M #3 3/16* ill Screen M #2 3/16* ill M #1 .40.38* 0.34 0.37 0.35 0.39 0.44 0.37 0.39

3 l 1/ "Screen /8 1 ill M "Screen /8 #3 1 ill M ■Screen #2 1/4 ill M #1 0.49* 0.25* 0.37*

t Averages 0.31 0.22 0.32 0.32 0.39 to

CONDITION OF HILLS 2 l Dry ill M #2 1 l Dry ill M #1 2 l Dry ill M #2 Dry ill M #1 Used Not #3 3 o Used Not #3 Dry ill M #3 1 l Dry ill M #1 2 i Wet ai M #2 fa Vet ai M #3 Dry ill M #2 . hs fgrs r nt nldd n aeae o aayi of aine Ec vle o a eaae run separate a for s i value Each variance. f o analysis or averages in included not are figures These A. 3 l Vet ill M #3 Vet ill M #2 Averages Dry ill H #1 l Dry ill M n is eul o bs, BD pt fot o 1 l . ill M 1 Ho. front pith B.D. f o , s lb to equal s i and

#1 Mill 1/8" Screen 1/8" Mill #1 #2 M ill 1/8* Screen 1/8* ill M #2 3 l 1/8**Screen ill M #3 IH IM H N. HL/OA PT REMOVED HILL/TOTAL PITH 1 FIOM THE FROM NO. PITH THE BAGASSE BASIS) (DRV 0.61 0.81 0.55 0.63 6.51 0.63 0.51 0.43 0.64 0.63 0.54 0.59 ot l of .. pith B.D. f o . s lb l ta to

#2 M ill 1/8" Screen 1/8" ill Screen M #2 3/16* ill M #1 #3 M ill 1/8" Screen 1/8" ill M #3 0.88 0.80 0.66 0.70 0.68 0.59 0.66 0.49 0.68 SCREED SIZES AL HI TABLE H

#2 M ill ill Screen M #2 3/16* ill M #1 #3 M ill 1/8" Screen 1/8" ill M #3 .208*0.80 0.89* 0.72 0.64 0.71 0.64 0.53 0.50 0.55 0.51 0.59 0.53 3/16" Screen

#1 M ill ill M #1 #3 M ill 1/8" Screen 1/8" ill M Screen #3 1/8" HOI #2 0.80* 0.82* 0.84* 1/4" Screen

I Averages 0.63 0.66 0.57 0.54

N «o 93

TABLE X III

BATA FOR POWER CONSUMPTION AND FffiD RATE FOR VARIOUS RPM OF THE SMALL HAMMER MUL

Vater used on Snail H ill, Straight Head, 11 Straight Hamers, 1 Twisted Hamer per row, 4 rows. 2455 RPM I K 7 7 it h Feed Rate Run No. Lbs. Feed Lbs. Min. KWq/Lbs. I

48-L-20 A .174 14.4 B .174 12.0 C .151 9.6

21 A .182 16.0 .0038 B .224 12.4 .0042 C .288 8.8 .0055

22 A .154 20.0 .0033 B .180 13.0 .0035 C .223 9.8 •0050

23 A .217 20.4 •0031 B .243 12.8 .0035 C .303 9.4 .0045

24 A .216 20.9 .0030 B . 2 a 13.6 .0037 C •260 9.3 .0047

25 A .164 13.8 .0044 B .164 11.6 .0047 C .195 8.9 •0055

Averages .207 13.1 .0042

1135 RPM

48-L-27 A .175 16.8 .0014 B .160 11.6 .0017 C .194 8.3 .0020

28 A .192 18.5 •0013 B .222 U .2 .0017 C .168 10.6 .0017 D .163 8.4 •0018

(Continued on next page) 94

TABLE X III (Continued)

Lbs. P ith Feed Rate Run Mo. Ubs. Feed Lbs. Min. KVH/Lbs. Feed

48-L-29 A .129 13.8 .0015 B .149 n.4 .0017 C .173 7.7 •0020

30 A .154 14.0 .0017 B .164 12.6 .0017 C .185 9.4 .0019

31 A .138 16.5 .0014 B .130 11.4 .0017 C .232 9.4 .0020

32 A .121 19,3 .0013 B .125 13.5 .0015 C .141 9.6 .0017

Arerages .165 12.3 .0017

795 RPM

48-L-33 A .121 22.5 .0009 B .135 12.6 .0011 C •132 9 .1 .0012

34 A .108 21.6 .0008 B .140 12.1 .0011 C .140 9 .0 .0012

35 A .159 18.4 .0010 B .147 11.5 .0011 C .168 8 .2 .0013

36 A .139 18.9 •0009 B .142 11.5 .0011 C .142 8.1 .0013

37 A •129 18.2 .0010 B .134 11.7 .0010 C .139 8,3 .0013

38 A .127 22.0 .0009 B .149 13.1 .0010 C .145 9.4 .0011 Averages .138 13.7 .0011 95

TABLE XIV

PER CENT SOLIDS AND PER CENT MUD IN VATER FROM THE STRAINER TANKS OF THE BAGASSE SEPARATION PLANT

Ron No* % Solids in % Mud lbs. Water ~ m-2 lb s . H2 O Drain Vater lbs. Ash in Feed lbs. dry feed

54-F-6 0*91 13.0 2.12 13.0 7 1.63 17.5 2.56 7.3 8 1*00 12.3 2.38 10.1 12 1.68 17.0 1.60 4 .2 15 0*56 10.5 4.92 12.0 16 0.37 8 .0 10.70 18.0

54-C-5 1.13 11.2 2.04 15.9 6 1.02 10.2 1.34 8 .9 8 1.31 16.7 0.78 11.4 9 17.2 0.68 4 .1 10 1.05 11.0 0.86 5.3 11 0.93 12.3 3.30 8.4 12 0.35 5.1 4.15 11.2 13 0.67 12.3 6.55 15.1 14 0.36 7 .0 8.70 17.6

Averages 0.93 12.1 3.51 10.8 I

TABLE XV

PARTICLE SIZE ANALYSES OF THE FIBER PRODUCT FROM THE BAGASSE SEPARATION PLANT

Rim No. 0 - 1 /2« 1 /2 - 1»» 1 - 1 -1 /2 " 1 -1 /2 “ 2 " 2 - 2 -1 /2 " 2 -1 /2 *

54»F-1 36.7 30.0 15.7 4.7 2 .1 10.8

2 62.1 23.2 11.0 1.4 1 .3 0 .0

3 36.5 29.2 11.5 3 .5 2 .3 17.0

4 30.6 35.2 11.9 8.9 2 .1 11.3

6 32.6 29.7 8 .8 14.8 2 .3 U .7

12 38.1 34.3 12.7 5.1 0.0 9 .8

16 17.5 34.5 19.8 11.9 4 .7 11.6 i 4 C -l 27.1 45.3 18.3 5.5 3 .8 0 .0

2 44.1 36.2 12.6 4.4 2 .7 0 .0

6 28.0 38.2 19.5 7 .0 2 .5 4.8

10 33.0 37.8 17.0 6.4 2 .6 3 .2

14 38.1 37.0 14.9 5.6 3 .2 1 .2

Arerages 35.4 34.2 14.5 5.8 2 .5 6 .7

«0 a> TABLE XVI

BONE DRY DENSITY VERSUS PRESSURE FOR FIBER AND PITH FROM THE BAGASSE SEPARATION PLANT

Density - lbs/ft3 Pressure - lbs/ft^

(1) F ib e r

Run No• M oisture ______

5 4 -F -l 82.6% Dry Density 3.10 3.71 4.08 4.48 4.68 5.04 P ressu re 0 27 50 80 106 131

54-F-2 83.3% Dry Density 3.37 3.91 4.18 4.50 4.78 P ressu re 0 31 51 76 102

54*F-3 54.9% Dry Density 3.98 5.26 5.63 5.95 6.37 P ressu re 0 31.7 57.7 82.3 108.0

54-F-4 83.9% Dry Density 3.40 4.08 4.43 4.63 4.85 5.09 P ressu re 0 30.8 58.7 81.1 106.3 132.3

54-F-5 82.4% Dry Density 4.18 5.08 5.29 5.53 5.78 P ressu re 0 32.2 52.1 77.3 104.7

54-F-6 83.0% Dry Density 3.63 4.32 4.69 5.02 5.17 P ressu re 0 32.1 54.5 79.7 107.2

54-F-7 83.4% Dry Density 3.41 4.26 4.31 4.60 4.94 5.18 5.32 5.51 P ressu re 0 32 59 87 111 131 156 182

54-F-8 80.7% Dry Density 3.74 4.64 5.05 5.25 5.50 5.94 P ressu re 0 32 58 77 99 125

54-F-9 52.7% Dry Density 3.29 3.97 4.59 4.81 5.23 5.37 5.67 5.96 P ressu re 0 32 46 72 100 126 158 184

(Continued on next page) TABLE XVI (C ontinued)

Bin No, Moisture

54-F-10 83.2$ Dry Density 3.06 3.63 3.89 4.16 4.40 P ressu re 0 32 55 81 100

54-F-12 81.9$ Dry Density 3.51 4.14 4.40 4.54 4.94 P ressu re 0 32 55 74 127

54-F-14 52.6$ Dry D ensity 3.14 4.04 4.34 4.59 4.82 5.42 P ressu re 0 32 55 75 100 147

54-F-15 54.6/S Dry Density 3.02 3.69 4.01 4.30 4.54 P ressu re 0 27 51 77 103

54-F-16 77.4/S Dry Density 3.41 4.33 4.65 5.20 5.42 5.94 6.19 P ressu re 0 27 47 81 111 135 161

54-C-2 82.5/S Dry Density 3.62 4.62 4.78 5.08 5.37 P ressu re 0 32 54.2 77.5 98

54-C-4 84.0$ Dry Density 3.43 4.00 4.30 4.50 4.70 P ressu re 0 32.9 53.9 74.5 101.2

54-C-5 81.9$ Dry Density 3.41 4.44 4.64 4.96 5.49 P ressu re 0 32.5 52.9 87.2 U 4 .2

54-C-7 45.5$ Dry Density 3.76 4.87 5.09 5.51 5.97 6.36 6.57 P ressu re 0 33.1 53.6 74.5 97.5 118.2 144.5

54-C-9 83.1$ Dry Density 3.08 3.56 4.02 4.33 4.54 4.73 4.86 P ressu re 0 33.0 53.5 83.4 106.4 122.4 158

54-C-10 82.1$ Dry Density 3.18 3.72 4.44 4.50 4.73 5.02 5.15 5.34 P ressu re 0 33.1 53.1 73.3 93.5 116.8 137.5 165

(Continued on next page) TABLE XVI (Continued)

Rtn No. Moisture

5 4 -C -ll 81.2* Dry Density 3.12 3.77 4.23 4.65 4.82 5.05 P ressu re 0 28.7 48.8 78.8 98.8 119

(2) P ith

54-F-3 43.0* Dry Density 3.70 4.69 5.11 5.44 P ressu re 0 30.2 57.7 82.3

54-F-4 50.0* Dry Density 3.81 4.79 5.35 5.70 6.00 P ressu re 0 26.7 54.6 80.0 105.8

54-F-5 49.8/6 Dry Density 5.14 6.40 7.10 7.32 7.56 P ressu re 0 32.2 52.1 77.3 104.7

54-F-6 50.4* Dry Density 4.35 5.59 5.88 6.25 6.57 P ressure 0 32.1 54.5 79.7 107.2

54-F-7 51.5/6 Dry Density 3.81 4.85 5.18 5.56 5.89 P ressu re 0 32 59 85 112

54-F-8 51.2* Dry Density 4.10 10.50 11.40 12.10 12.60 P ressu re 0 32 58 77 99

54-C-2 50.656 Dry Density 3.60 4.65 5.13 5.42 5.66 P ressu re 0 29.7 52.2 79.5 100 100

TABLE XVII

RESULTS OK ANALYSES OF FIBER FOR DESIRABLES AND UNDESIRABLES

Run Nunbcr Condition of Mills* Desirables, % Undesirables,

No. 1 No. 2 No. 3

53-M-2 D D D 80 20 5 D W tf 89 11 6 D W w 76 24 7 D S w 72 28 8 D S w 98 2 9 D S w 92 8 10 D s w 90 10 11 D w w 90 10 12 D w w 84 16 13 D D D 83 17

53-H-2 •D D D 8b 14 3 D W s 92 8 4 D W w 91 9 5 D V w 90 10 6 DS w 83 17 7 D D D 79 21 8 D S W 90 10 9 D W W 85 15 10 D W W 90 10

Average 86.3 • 13.7

Variations in Analyses for Desirables on Separate Samples % Desirables

53-H-9 Sample 1, each run by a . 85.0 a different person. b . 82.5 c . 85.5 Range 3 .0

53-H-2 Sample 2, each run by a . 90.0 the same person. b . 88.4 c . 92.5 • Range “T T

* . D Dry W Wet S—--Steam 101

TABLE XVIII

PROPERTIES OF KRAFT PULP PRODUCED FROM DRY AND VET SEPARATES FIBER AND BAGASSE

Samples of bagasse and dry separated fiber, from run H-7, and vet separated fiber from run M-ll were sent to the Research Laboratory,

Southern K raft D iv isio n , In te rn a tio n a l Paper Company, M obile, Alabama, for evaluation* A Kraft cook was made on each of the samples and the resulting pulp tested. Data on the tests are summarized below. Coltmm 1 i s th e f ib e r product from wet se p a ra tio n , Column 2, th e f ib e r product from dry separation, and Column 3 is raw bagasse; Colums 4 and 5 include representative data for easy bleaching pine and gum pulps, respectively.

Coluim Number

1 2 3 4 5

% Active Na20, on B.D. Bagasse 11.0 11.0 11.0 11.0 11.0 Cooking pressure, p.s.i. 110.0 110.0 110.0 110.0 110.0 Time to pressure, hrs.. 1.0 1.0 1 .0 1 .0 1 .0 Time on p re ssu re , h r s . 1 .0 1 .0 1.0 1 .0 1 .0 TAPPI Permanganate No. 6.10 7.10 7.25 20.0 14.0 % Screenings (.010* plate) On B.D. Pulp 1.10 1.75 0.31 % Total Yield, on B.D. Bagasse 55.85 52.45 44.77 47.50 50.00 Canadian Standard Freeness 550.0 450.0 280.0 720.0 690.0 % Ash, on B.D. Pulp 0 .5 1 .0 3.5 0 .1 -0 .2 0 .1 -0 % Pulp retained on: 14 mesh 2.1 1 .4 1 .8 30 mesh 30.5 22.6 17.8 50 mesh 23.1 23.0 22.0 100 mesh 29.9 34.2 36.1 % Pulp through 100 mesh 14.4 18.8 22.3 6 .0 16.0

Several hand samples made from the above screened pulps were tested by the Gaylord Container Corporation.

(Continued on next page) 102

TABLE XVIII (Continued)

B asis Wt. C alip er Mullen, Bursting Tear lb s . in . % %

Pulp from 44.5 .0045 89.0 110.0 wet separated fiber

Pulp from dry 45.0 .0040 83.0 117.5 separated fiber

Pulp from Bagasse 44.5 .0050 88.4 104.5

Identification of Terms vised For Testing of Handsheets

Basis weight - weight of a 500 sheet ream of 24 x 36 inch sheets, lbs.

Caliper - thickness of a single sheet, inches.

Mullen - this is a •pop" or bursting test. The bursting pressure for a standardized, circular area is the measure commonly taken for the burst* ing strength, and is sometimes recorded as points.

This test may also be expressed as the Bursting Percent which is the ratio of bursting strength in points, to the basis weight multiplied by 100. This ratio allows the intrinsic strength of papers of different weights to be compared.

Tear - This test is a measure of the force in gram-centimeters required to tear the length of 16 sheets (137.6 cm). This value is then divided by the basis weight and multiplied by 100 to obtain the per cent values which are reported.

Details of all testing procedures for paper are available in the

TAPPI Standards(14°). 103

RESULTS OF TESTING DRY AND WET SEPARATED FIBER FOR USE AS A WALL BOARD RAW MATERIAL

Six samples of the fiber produced in the bagasse separation plant vere sent to the Celotex Corporation in Marrero, Louisiana, for evalua tion. Listed belov are comments and conclusions regarding the samples sent. Following this is a chart identifying the conditions imposed on each sample.

Bale No. 1 - Fibrillation (length to diameter ratio) is low, yielding short stocky bundles. When this is further refined for use in building board it would yield a very short fiber. The ideal fiber should be long and thin (silky) - better than 80 to 1 length to diameter ratio - and be tough and resilient.

Bale No. 2 - Fairly light in color. Excellent fibrillation. Would prob ably need very little additional refining. If this is so, then it should be highly satisfactory in board formation, especially since there are very few pith bundles or stocky fiber bundles.

Bale No. 3 - Grayer color due probably to dirt. Contains some pith bundles in bale as well as a considerable amount of fiber bundles. The fibrilla tion that does occur yields very long, desirable, fibers. Very little usable fiber is lost in the pith fraction 3A, the least of all the dry sam ples.

Bale No. 4 - The poorest of all the sasqples sent, not in color, but due to poor fibrillation and due to a large amount of pith adhering to the fiber bundles. Although fiber bundles are not too short, final refining may result in too short a fiber.

Bale No. 5 - The best of all the samples sent. Almost pith free. The fibrillation is excellent^ yielding very few fiber bundles. The very light color indicates that mill losses (washing, refining) would probably be at a minimtm. As a matter of fact, little additional refining would be necessary for certain boards.

Bale No. 7 - Similar coloration to Bale No. 3. The degree of fibrillation is excellent except for a larger amount of chunks than No. 5. The bales are moderately pith free. Both Bales 5 and 7 have a high percentage of usable fiber lost in the pith fraction.

Bales No. 5 and No. 7 seem to be the best, if economics were unim portant. Similarly Bale No. 4 yielded the poorest fiber for our process. Due to cost of drying bagasse, which is necessary prior to storage, this reversal of "wet" and "dry'*processes is unfortunate. 10 4

All fiber saaplcs appear to have Merit as potentially-bcttcr raw material for insulation board than regular bagasse. There is some ques

tion about the feasibility of storing vet, baled bagasse, assuming that

it would not be used green. The best indication of the •wet*' versus "dry" material storcability is in observing the 3-month old pith samples. AH

the wet separations were very dark in color and had considerable Mold and fungus growth. The dry samples were light in color and practically

growth free.

i 105 #3 Mill 1/8" Screen #1 Mill #2 1/4 "Screen M ill 1 /8 " Screen Bale No. 7 Rin C-10 #1 Mill 3/16" Screen#3 Mill 1/8" Screen #2 Mill 3A0" Screen TABLE XIX TABLE SCREEN SIZES SCREEN B ale No. 5 Run F-10 Run C-7 Bale No. 4 B ale No. 3 Rin F-7 M ill 1/811 Screen #3 Mill 1/8" Screen #1 Mill 3/16" Screen §2 IDENTIFICATION OF SAMPLES SENT TO CELOTEX CORPORATION TO CELOTEX SENT OF SAMPLES IDENTIFICATION Bale No. Run 2 C-2 Bale No. 1 Run C -l #3 Mill 1/8»'Screen #1 Mill #21/8" M ill Screen 1/8*1 Screen M ill Dry M ill Dry M ill Dry

#3 M ill Wet 02 #3 M ill Wet #1 M ill #2 Dry M ill Wet # 1 #1 Jiil'i #2 Dry M ill Wet #3 Hot Used #1 Mill #2 Dry Mill #3Dry Mill Drr §1 #2 Mill #3 Dry Not used ST1IH AO NOIIMNOO TABLE XX

YIELDS OF PULP FROM DRY AND WET SEPARATED FIBER USING A NEUTRAL SULFITE COOK

Temperature o f 170*C 160-C D igestion

Chemical/Fiber 14 g Na*S03 8 g Na2S03 14 g N*2S03 8 g N a ^ 0 3 R atio ffas/LOO gas 5 g Na2003 3 g Na2C03 5 g Na2C03 3 g NajSOj o f F ib e r 1 t Water/Fiber R atio 5/1 7/1 5/1 7/1 5/1 7 /1 5/1 | 7 /1

Wet or Dry Separation Vet Dry Vet Dry Vet Dry Vet Dry Vet Dry Vet Dry Vet Dry Vet Dry ; o f F ib er 1 ! ■ Time i 59.5 63.1 58.8 62.5 65.5 70.5 62.8 67.8 61.7 66.4 60.3 69.4 76.5 76.9 74.9 79.1 2 H rs.

Time 57.3 58.0 71.9 68.0 1 .5 H rs. 63.4 63.5 65.5 75.7 72.2 68.8 59.5 66.5 64.9 75.8 77.5 75.5

o 107

TABLE XXI

SUMMARY OF ANALYSIS OF VARIANCE FOR THE YIELD OF PULP FROM DRY AND WET SEPARATED BAGASSE (Method of Calculation Reference 3)

Source of Degrees of Mean Square F Variation Sum of S<,uarcs Freedom

Chemical/Fiber Ratio 757.6 757.6 46.7

Temperature 172.5 172.5 11.6

Water or No 123.6 123.6 7.6 Water on Mills

Time 9.8 9.8 0.6

Water/Fiber Ratio 3.2 3.2 0.1

Pooled Interaction 422.0 26 15.6

T otal 1488.7 31

For 1 and 26 degrees of freedom an F of 4.22 is significant at the

5/£ level of confidence and one of 7.72 is significant at the 1 % le v e l.

Averages of yields for variables investigated in pulping of dry and wet separated fiber are reported below

F i r s t Second Condition Condition Difference

(1) Chemical/Fiber Ratio 62.9 72.6 9.7

(2) Temperature 65.5 70.1 4.6

(3) Water o r No Water on M ills 65.8 69.8 4 .0

(4) Time 67.2 68.3 1.1

(5) Water/Fiber Ratio 67.5 68.1 0.1

The first two variables are significant at the l£ level, and the third at the 5 The fourth and fifth are not significant. TABLE m i

PHIMANGANATE NUMBERS OF PULPS FROM DRY AND WET SEPARATED FIBER USING A NEUTRAL SULFITE COOK

Temperature o f 170*C 160*C D ig estio n

Chemical/Fiber 14 g NajSOa 8 g Na2S03 14 g Na2S03 8 g Na2S03 j R atio I gas/100 gas 5 g N*2C03 3 S N*2C03 5 g Na2C03 3 g N»2^®3 o f F ib er

Water/Fiber 5/1 7/1 5/1 7/1 5/1 7/1 R atio 5/1 7/1

Wet o r Dry Separation Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet Dry o f F ib e r

Tine 2 H rs. 10.2 7.3 7.1 7 .2 22.2 19.8 20.4 1 9 .1 9 .1 7 .4 8.3 7.8 15.6 13.9 14.7 14.5

Time 9 .3 8 .0 1 .5 H rs. 7 .7 7.4 18.5 17.5 20.7 1 6 .9 11.8 10.1 1 1 .1 1 0 .4 19.4 18.9 15.7 12.7

- ______109

TABLE XXIII

SUMMARY OF THE ANALYSIS OF VARIANCE FOR THE PIRMANGANATE NUMBERS OF THE PULP FROM DRY AND WET SEPARATED FIBER (Method of Calculation) Reference 3)

Source Sum of Squares Degrees of Mean Square F Freedom

Chemical/Fiber R atio b04.05 1 o04.65 13b.48

Water or No 18.14 1 18.14 4.15 Water on Mills

Temperature 11.39 1 11.39 2.57

Water/Fiber R atio 0.01 1 0.01 0.00

Time 3.31 1 3.31 0.75

Pooled Interaction 115.22 22 4.43

TOTAL 752.72 31

For 1 and b degrees of freedom an F of 4.22 is significant at the 5% level of confidence and one of 7.72 is significant at the 1% le v e l.

Average Permanganate Numbers for variables investigated in the pulp ing of dry and wet separated fiber are reported below

F ir s t Second C ondition C ondition D ifference

(1) Chemical/Fiber Ratio 8 .8 17.5 8 .7

(2) Water or No Water on Mills 12.4 13.9 1 .5

(3) Temperature 13.8 12.6 1 .2

(4) Water/Fiber Ratio 13.7 12.7 1.0

(5) Time 13.9 12.4 1 .5

Only the first variable of chemical to fiber ratio was significant and this was at the 1% level. NO. 340 -20 DIETZGEN GRAPH PAPER EUGENE DIETZGEN CO. 20X20 PER INCH MAOC IN V . S . A«

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irr26(£f 125 i G. DISCUSSION OF RESULTS

The effect of the variables studied in this investigation will

best be understood by referring to the graphs of the iteas being dis

cussed, along with the tables from which the data were taken. When it

was not possible to plot the results, they were reported in tabular form.

(1) V ariab les A ffe c tin g th e Amount o f S e p aratio n

One of the most significant variables affecting the amount of

separation is the hole diameter in the screens immediately under the

hammers. Figure 13 shows the per cent of the bagasse feed which was re moved in the first mill as pith for the three different screen sixes that were used (dry basis). The data are plotted from Table X. The vertical lines which are drawn through each point represent the range of values which were obtained in the investigation. An analysis of variance was performed on these data and the differences between screen sizes were significant at the 1 % level. One of the reasons for such a wide range in the per cent separation is believed to be due to so m e of the screen holes becoming plugged. On several occasions, when the screens from the mills were removed, some clogging was n o tic e d on th e feed end o f th e hammer m ill, but this was not serious. It is believed that two twisted hamers on this end would remedy the situation.

Table XI shows the ratio of total pith removed in all mills to the quantity of feed. This may be expressed as a fraction separated. An

126 127

analysis of variance was performed on these data and both differences

encountered between screen sizes and those encountered between various

conditions of the mills were significant at the 1% level. It should be

noted that the data included under the column for the 1/411 screen size

in the first mill was not included in the analysis of variance. All

the data reported in Table XI are from the 1954 grinding season. It was thought that this table could be finished by including some of the

runs made during the 1953 season* since the 1/4 inch and the two 1/8

inch screens were used at that time. This was not the case* since the direction of rotation of the No. 1 and No. 2 m ills was changed during the sumser of 1954* and it had a marked effect on the amount of material be ing separated as pith. The average pith to feed ratio for Halbrook's group was .47 and for McCombs1 group was .44. These figures for 1953 do not compare with the average of .37 for three runs of the 1954 season.

The ratio of pith removed in the No. 1 mill to the total removed in all mills for the 1954 season is reported in Table XII. An analysis of variance was also calculated for these data and both the differences encountered between screen sizes and those encountered between various conditions of the mills were significant at the 1% level. Again* the data under the column for the 1/4 inch screen size in the first mill were not included. During the 1953 season for Halbrook's group all of these values were over 0.90. As before* this difference was probably caused by the change in direction of rotation of the No. 1 and No, 2 mills during the sumner of 1954. 128

An effort was made to obtain data which showed the effect of feed

rate on separation. The only correlation that showed significance in

volved the data from Table XIII, at 795 RPM for the snail banner mill of

Plate XXIII. This relationship is reported in Figure 16. It has a cor

relation coefficient of -.546 which is significant at the 2% le v e l. As

can be seen in the graph, the effect of feed rate on the amount of sepa

ration is not a large one. Figure 15 shows the effect of feed rate oa

separation at 1135 RPM, but this correlation is only significant at the

10% level. The corresponding plot for 2455 RPM is even more scattered and

was not included in this report.

The only approach that could be used to determine what effect the

various mill speeds had on the amount of separation was by Analysis of

Variance. The average pounds of pith/lb. of feed for 2455, 1135, and

795 RPM was .207, .165, and .138, respectively, as seen in Table XIII.

The differences in these three figures were found to be significant at

the 1% level.

Plates XXVIII, XXIX, and XXX show the bagasse, fiber and pith

fractions, respectively. One can see, by comparing the first two illus trations, that the large particles which are present in the bagasse have been broken down and are practically free of pith. The increased fibril lation (length to diameter ratio) of the fiber, which is an important property in wall board manufacture, can be observed. The fiber in Plate

XXIX was produced under the following conditions of the bagasse separa tion plant; the No. 1 mill contained a 1/4 inch screen; the No. 2 and

No. 3 m ills, 1/8 inch screens. Vater was used on the No. 2 and No. 3 129

mills* It can be noted that there are some fiber particles in the pith fraction shown in Plate XXX. This is because the sample of pith was ob tained from the No. 1 m ill which contained the 1/4 inch screen. This large size screen allows some fiber to pas3 through into the pith fraction, but this is not as noticeable when smaller screen sizes are used.

(2) Variables Affecting Power Consumption

The variation in total power consumption of the Bagasse Separation

Plant with feed rate is best seen by referring to Figure 7. The data plotted here are from 54 separate runs performed over three grinding seasons, and include the power consumed by the rating of 81.5 horsepower connected load* Of this amount, the connected load of the No* I, 2 and

3 mills was 25, 20 and 15 horsepower, respectively. It is noted that the power used per pound of bagasse decreases as the feed rate increases. The line drawn through the points for three mill operation is that of the eq u atio n :

25/Wet Feed Rate, Lbs./Hr. a KWH/Lb. Vet Feed

It is not necessarily the line which best represents the points on the graph, although the fit seems very good. Host of the points in the upper left were taken in the 1952 season when the recirculation pimps were still in use. This probably accounts for the slight off-set of these points. If it were not for these, a constant of 24 would make the equa tion fit the experimental data better. It is noted that the same general curve is applicable to the 2 mill operation except the equation in this case i s :

17/Wet Feed Rate, Lbs./Hr. = KWH/Lb. Vet Feed 130

These two curves show that, whether 2 or 3 Kills are used in the

Bagasse Separation Plant, the smallest amount of power per pound of through-put will be obtained at the highest permissible feed rates of bagasse*

Figures 8 and 9 show the power consunption data for each rim plot ted versus the wet feed rate and the water rate, respectively* Since the

H/Hr* will cancel, it may be said that this is the average power demand in Kilowatts. No conclusive trends were obtained, therefore, horizontal lines were drawn at the average KWU/Br* of a ll the runs. Because of this, one may infer from these plots that the variations in feed rates and water rates had little or no effect on the power used per unit time*

The data for Figures 7, 8 and 9 are recorded in Table 11* An average of all the KVH/Hr* figures from this table for 3 mill operation gives 24*8 and for two mill operation, 17.3.

Table III shows the instantaneous power consumption of the individ ual tuumaer m ills. These were taken on a strip type recorder for the following load conditions: idling with no bagasse feed; bagasse feed only; bagasse feed plus steam injection; and bagasse feed plus water injection*

Vet operation consumes about 3 times the power used when no water is in jected into the mill*

Table IV shows the load factor on. the apparatus. The factor for the m ills was 34*6£ and for the accessories, 59.1%.

Some data were taken on a small hammer mill sim ilar to Plate XXIII, but without the sloping head, to determine the effect of feed rate and

RPM on power consumption. These are reported in Figure 14. The correlation 131

coefficients for the 2455, 1135 and 795 RPM lines are *90, *92 and .90,

respectively, and are all significant at the 1% level. This plot is in

cluded only to shov the effect of RPM on the pover consiasption, since nore reliable figures are available to shov the pover constssption of the

large Bagasse Separation Plant. The data for this plot vere taken from

Table XIII. Since all of the lines in this graph converge between 35 and 38 lbs./sdn. feed, one may say that in general the faster the feed rate, the less the difference in pover consiasption due to a difference in RPM of the a ill.

(3) Ash Contents of Bagasse, Fiber and Pith

Figure 10 shows the plot of per cent ash in the fiber versus per cent ash in the feed for dry separation. A correlation coefficient of

•83 was obtained which is significant at the 1 % level. The regression equation of the calculated best lino of fit is:

I - .41X* 1.18

A note of interest here is that the fiber product will contain nearly the sane per cent ash as the bagasse if the bagasse has 2 per cent or less ash. Since clean bagasse usually contains about 2 per cent ash, one night say that the biggest inprovenent to be gained fron dry operation would be with very dirty bagasse.

Figure 11 shows the plot of per cent ash in the fiber versus per cent ash in the product for wet separation. A correlation coefficient of .74 was obtained which is significant at the 1% level. The regression equation of the calculated best line of fit is

Y - .162 x ♦ 1 132

One should note the Much smaller slope of 0,162 for vet operation, as compared to .41 for dry operation. One interpretation is that for very high ash contents in the bagasse, the vet operation can produce a fiber vhich is much lover in ash than can the dry operation. There is not a great deal of difference betvecn the two types of operation if the original bagasse is extremely lov in ash (2 to 3 per cent)*

Figure 12 is a correlation vhich vill predict the quantity of vater necessary to reduce the ash content of a certain bagasse to a specific quantity. The correlation takes the form of the hyperbola:

Y «* 1.2/(X - 0.5) ♦ 1

To give an application of this graph one can assume that a bagasse of 5 per cent ash is being fed to the unit and it is necessary to produce a fiber of 1.5 per cent ash. In Figure 12, the line of 1.5 per cent ash in the fiber is folloved to the curve and then a vertical line to the x axis. One obtains 330 pounds of vater per pound of ash in the feed as the necessary amount of vater. If 1000 pounds per hour of bagasse is being fed to the separator,. this means that 50 pounds per hour of ash is being fed. Fifty times 330 is equal to 16,500 pounds of vater/hour or nearly 2000 gallons per hour. As can be seen on the graph, there is seme scattering of the points so a safety factory should be alloved if it is necessary to hold the separation plant rigidly to a maximum per cent ash in the fiber; hovever, above 300 pounds of vater per pound of ash fed, the ash in the fiber vill be very unlikely to exceed 2 per cent. Very little reduction in ash content of the fiber product is obtained above

400 pounds of vater per pound of ash fed. 133

Table V presents a comparison of ash in the bagasse feed, ash in vet separated fiber, and ash in the dry separated fiber* These data were those used for Figure 10* The data for Figures 11 and 12 are reported in

Table VI.

Table VII shows the approximate reduction in ash content vhich is obtained by each sdll. Each succeeding mill takes out progressively less ash, until in the last sdll the fiber is reduced from 1.60 per cent to only 1.3 per cent ash. The conclusion that the third sail is not neces sary should not be reached on the basis of this evidence since for some applications, such as Celotex board, the increased fibrillation obtained in this third mill is desirable* This vill be discussed in nore detail la te r*

A stannary of all the ash analyses is reported in Table VIII* The various conditions under vhich the Bagasse Separation Plant vas operated are indicated. Again, one sees the obvious difference between dry and vet separation* The other variables do not seen to have any important influ en ce.

Table IX shovs the difference in Si02 and Fe 2© 3 content of the ash for the bagasse feed and the fiber product. This large change in F e ^ content vas observed qualitatively on many of the ash analyses. It could be noted by the pink color vhich appeared in the bagasse ash and the ab sence of this color in the fiber ash.

(4) Properties of Bagasse, Fiber and Pith

The particle site distributions of the fiber product for several 134

runs are reported in Table XV* The average of these determinations are

reported in Figure 19. In every case, the fiber product contained more

than 5 0 per cent of particles under 1 inch in length and in most cases

this figure ranged from 70 to 80 per cent*

The increase in density of fiber and pith as a function of an in

crease in pressure is reported in Table XVI* A typical curve to represent

these data is shorn in Figure 20. These data are valuable in determining

the capacity of a vessel, such as a digester, if it is to be loaded with loose fiber, or of bins vhich arc to hold loose fiber or pith before they are farther processed.

The results of the desirables and undesirables analyses made during

the 1953 season are shown in Table XVII. One should realize that the de sirables are practically pure fiber and a large part of the undesirables will be fiber to vhich pith is adhering* This is explained in the section on Analyses. A safe estisiate vould be that the fiber product for the 1953 season averaged less than 10j6 pith. By referring to Figure 3, one may see the effect this has on the quality of paper and pulp from bagasse. The

10 per cent pith figure vould correspond to the 20 per cent figure on the x axis of this graph.

Pressure drop data vhich were collected an the pith, fiber and ba gasse are shown in Figure 21* The apparatus used is shown in Figure 6*

The air flov rate was 3.35 ftV ain. as determined by Reference 14. The air velocity in the tovcr corresponded to 16 inches differential pressure on the mercury manometer across a 1/8 inch orifice, in a 1/2 inch line, using pipe taps. It is noted that the pressure drop through the fiber is 135

Much less than either the bagasse or pith.

For drying of the materials in this colusn, the air rate ranged

from 2 to 3 cubic feet per minute* In five days the pith in the tower vas dried from an original moisture of 50 per cent to 34 per cent in the

top section, 14 per cent in the middle section, and 4 per cent in the bottom section* For bagasse, the figures are 20 per cent in the top and

5 per cent in the center and bottom sections.

These results show that it is possible to dry bagasse or dry separated fiber to a very low moisture content by blowing unheated air through a coltmm of bagasse* More extensive work on a larger scale was done along these lines during the 1954 grinding season^60).

(5) Drain Vater

The data collected on the water leaving the strainer tanks are reported in Table XIV. It is seen that the per cent solids averaged only about 1 per cent; however, the per cent mud on settling for 24 hours was 12 per cent, by volvmie. Two graphs were drawn from these data,

Figures 17 and 18* The first shows the relationship between per cent solids in the drain water and the pounds of water per pound of dry ba gasse fed to the tsiit. The correlation coefficient in this case is .89, and is significant of the 1% level. In Figure 18, the plot of weight per cent solids in the drain water versus per cent mud by volume is shown.

The correlation coefficient in this case is .90, and is significant at the

1% level. These data are of value in knowing the quantity of mud which would have to be settled from the water effluent if it became necessary 136

to reuse the vater to prevent stream pollution.

To give an application of these graphs, one can assume that 10

pounds of vater per pound of dry bagasse is being used and the flow rate of bagasse is 1000 pounds per hour (dry basis). By using Figure 17, one can see that one per cent solids is to be expected in the drain vater for 10 pounds of vater per pound of dry bagasse feed. Then from Figure

18 one can see that for one per cent solids in the drain vater about

12.5 per cent mud by volume can be expected. Since the flov of vater is

10,000 pounds per hour (160 cubic feet), one can expect 20 cubic feet of mud per hour. One should be reminded that this volume could be reduced by a thickener or any rake mechanism vhich vould produce a mild agitation of the mud to aid in its consolidation. Also this volume is based on a

24 hour settling time.

(6) Evaluation of the Fiber Product

(a) Kraft Pulping

Samples of vet separated fiber, dry separated fiber and rav bagasse from the 1953 grinding season vere sent to the International Paper

Company in Mobile, Alabama, for evaluation. The results of the tests are reported in Table XV1I1. The permanganate number is the smallest for the vet separated pulp denoting that it contains less lignin and vill require less bleaching. An important item is that the yield of pulp is highest for the vet separated fiber and is also high for the dry separated material.

Since the cost of the cellulosic rav material for the pulp and paper in dustry represents a large portion of the price of the final paper, a high 137

yield is important. The high yield coupled with the low permanganate

number shows the superior quality of the wet separated fiber. The high

est per cent screenings for the two fiber products mean a little more

material would have to be recycled to the digesters or be discarded. The

fact that the wet separated fiber pulp has a higher freeness is important.

Bagasse is notorious for not draining well on the paper making machine.

Even though the wet separation has improved the draining ability of the

pulp, it is still not as good as easy bleaching pine or gum pulp. The

fact that the ash content is lower for the vet separated fiber means that

there vill be fever inperfections in the final paper due to dirt particles.

It is also approaching the range of ash obtained in pine and gum pulps.

The sieve analyses show that the amount of fine material is lover in the

vet separated fiber pulp than in the other two. From these data, one

may see that a significant improvement vas made by the Bagasse Separation

Plant, the greatest being for vet separation.

Several of the small sample sheets of paper which vere made from

the above pulps were tested by the Gaylord Container Corporation in

Bogalusa, Louisiana. These results are reported in Table XVIII. No

definite conclusions can be drawn except to say that these data represent

a range of figures which vould be expected from bagasse or fiber pulped

by the Kraft process.

(b) Wall Board

The samples identified in Table XIX vere sent to the Celotex

Corporation in Marrero, Louisiana, for evaluation. The comments in the

section aTesting of Fiber for Use by the Celotex Corporation", (page 103) 138

indicate that the best fiber products are bales Mo* 2, 5 and 7. These vere all vet separated samples* It is also said that these samples are

the best since they have a higher fibrillation (length to diameter ratio)*

Again, the vet separated fiber is shovn to be the best. * (c) Pulping of Vet and Dry Separated Fiber by the Neutral Sulfite

P rocess

The results of the pulpings performed in the Apparatus shown

in Plate XXVI are reported in Table XX* This experiment vas designed so

that the significance of the variables could be determined by statisti

cal methods* It is noted that two conditions vere chosen for each of 5

variables, Temperature, Chemical/Fiber ratio, Water/Fiber ratio, Vet or

Dry Separation of the Fiber and Time* For each of the 32 runs the yield

of pulp vas reported on the basis of the bone dry fiber charged to the digester. Upon completion of the runs the analysis of variance vas per formed and a summary of the values reported in Table XXI* The highest F obtained is that for the Chemical/Fiber ratio* The difference in yield caused by this variable vas 9*7 per cent and vas found to be significant at the 1 per cent level* The difference in yield due to temperatures vas

4*6 per cent* This vas also significant at the 1 per cent level* The difference in yields obtained between dry and vet separated fiber vas 4 per cent* This vas found to be significant only at the 5 per cent level*

The other tvo variables of Time and Water/Fiber ratio vere found not to be significant* This statement should be qualified in that if the tvo times vere chosen at extremes, surely they vould have been significant.

The interpretation in this experiment should be that whether 1*5 hours or 139

2 hours vere chosen for the digestion time, no significant difference vould occur in the yield of pulp. The same can be said for the tvo vater/fiber ratios vhich vere used. It is thought by some in the pulp and paper industry that the vater/fiber ratio and time are critical in pulping operations. This experiment does not substantiate that belief.

It vas obvious in viewing the pulps that the higher chemical concentra tion gave a light colored, veil disintegrated, easy bleaching pulp, whereas the pulps made from the lover concentration were dark in color, not veil disintegrated, and vould be difficult to bleach.

The TAPP1 Permanganate Numbers vere checked on a ll the pulps vhich vere produced. These values are reported in Table XXII. An analysis of variance was also performed on these data, a sunwary of vhich is given in Table XXIII. As can be seen, the only variable vhich vas found to have significance vas the chemical to fiber ratio and this vas at the 1 per cent level.

(7) Bagasse Flow Problems

The folloving points are discussed in order that one may better understand some of the principles involved in obtaining a continuous flov of bagasse through an apparatus:

Referring to Plate XIX, one can see that there is a sharp edge where the outlet chute of the bucket elevator joins the body. It vas observed that if the bagasse being processed contained a quantity of long stringy pieces they vould have a tendency to collect over this edge.

When enough of these collected, it vould then stop the smaller pieces 140

and the elevator would become plugged. Because of this tendency, pieces

of bagasse, over about one foot in length, were not fed into the elevator.

On the occasion when these long pieces were present in the bagasse, it

was only a very small percentage of the total quantity.

Plate XVI shows the point at vhich the bagasse dropped from the

main feeder scroll into the No. 1 feeder scroll. No difficulty was en

countered here except at the very high feed rates (4000 pounds wet bagasse

per hour)• These rates could be obtained when the bucket elevator was not

used and the bagasse fed directly from the main conveyor vhich handled the

bagasse from the grinding m ill. To improve this point of transfer, the

hole in the bottom of the main feeder scroll should be lengthened to allow

a longer time for the bagasse to fall. Prom Plate V, it can be seen that

this would necessitate making the No. L feeder scroll slightly longer.

It can also be seen, in Plate XVI, that if the hole were made wider the

sides would become perfectly straight, eliminating that resistance to

flow. With this change, there would be less tendency for the bagasse to

jam against the end of the feeder scroll at high feed rates.

Plates XVII and XVIII illustrate the next point of importance. It

can be seen that the scroll blade does not extend all the way to the blind

end of the feeder. Because of this, seme material has collected between

the blade and the end of the feeder, as can be observed in the photograph.

This point only gave trouble at the very high feed rates. In Plate VII, one can see an inspection door in the fiber chutes. This door could be opened while the apparatus was running to check the fiber chute. A simi lar door is located in the fiber chute in Plate IX, but cannot be seen. 141

The obvious improvement here would be to have a closer tolerance between

the scroll blade and the end of the feeder. If the No* 2 and No. 3 feeder

scrolls were made longer, this would allow both the right and left (looking

at photographs) sides of the fiber chute to diverge. This would aid in

the flow of material since it is necessary for the front and back sides

of the fiber chute to converge.

One additional observation is that in conveyors as shown in Plates

XXI and XXII the fiber product cannot be allowed to drop directly on the

chains to which the slats arc connected. If this is done, the fiber will be forced into the chain by the sprockets to such an extent that the con veyor will beconc jansed. H. CONCLUSIONS

An apparatus built around specially designed swing hawner mills has been developed which w ill separate, effectively, the pith or juice bearing cells and dirt from bagasse. It will operate for extended periods, without stoppages, and perform the separation either with or without water injection. The process is continuous.

The bagasse used in > this investigation was produced from mechanical ly harvested cane. It contained more trash than would bagasse produced from hand harvested cane.

The most important variables affecting the amount of separation are the hole diameter of the screens in the mills and wet or dry operation.

The number of hammer m ills, RPM of the m ills, number of twisted hammers, and feed rate were found to infleunce the amount of separation.

The power used per pound of through-put was reduced as the feed rate increased both for two and three mill operation. This can be predicted by a simple equation. The feed rate and water rate were found to have little or no influence on the total power consumption of the plant per unit time, but for individual m ills, it was increased by water or steam injection.

The cleanliness of the fiber was better for wet operation than for dry as indicated by the ash analyses. For wet operation, the effect of water rate on both ash in the fiber and solids in the drain water was de termined. The per cent solids in the drain water was correlated with the per cent mud.

142 143

Particle size distributions of the fiber vere determined, and den

sity versus pressure relations established for pith and fiber. The

pressure drops of air flowing through bagasse fiber, and pith vere obtained

and bagasse vas dried with low velocity, unheated, air.

The evaluation of the fiber product shoved that the most significant

variables on yield in Neutral Sulfite pulping vere the chemical to fiber

ratio, the temperature of digestion, and whether or not vater vas used on

the hamner mills for separation. For kraft pulping, the vet separated

fiber vas shown to be a better rav material than the dry separated fiber;

and the dry separated fiber to be better than the rav bagasse. For manu

facture of vail board, the vet separated fiber vould need little additional

refining since its fibrillation (length to diameter ratio) is higher than

that obtained in dry separation.

The cost of fiber produced from a comaercial size bagasse plant vas

calculated and found to be $6.35 and $5.52 per ton of dry fiber based on a

65 day and 130 day operating season, respectively. This includes the cost

of bagasse at $2.50 per ton (dry basis) and is based on a fiber yield of

60/C of the whole bagasse. One is reminded that in ordinary comnercial

practice, vail board manufacturers indicate that for every 100 tons of

bagasse purchased, about 70 to 75 tons is present in the finished product.

Because of this, the actual raw material cost is not $2.50 per ton, but

somewhat higher. It is the author*s opinion that the depithed material vould not be subject to the same losses as the whole bagasse. SELECTED BIBLIOGRAPHY

(a) Books and B u lletin s

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67. Karnik, M. C., Sen, D. L., "Preparation of Viscose and Cellulose Acetate from the Pulps of Indigenous Ccllulosic M aterial,•' J. Sci. Ind. Research (India), 9B, (1950), 201-217.

68. Keller, A. G., "Louisiana Sugar Cane Bagasse," Paper Trade journal, 134, (May 2, 1952), 29.

69. Kelly, F. H. C., "Composition of Bagasse Ash," Proc. Queensland Soc. Sugar Cane Tech. (1944), pp. 41-43.

70. Kumagava, Ha, and Shimomura, K. W., "Chemical Composition and Digesti bility of Bagasse and Rice Straw," Paper, 32, No. 2, (1923), 7-10.

71. Kvong, H. L., "Firing Powdered Coal in Bagasse Burning Furnaces," Sugar, 48, (March 1953), 50-51.

72. Lathrop, E. C., "The Celotex and Sugar Cane Industries,". Ind. Ehg. Chen., 22, (1930), 449-460. 149

73 • * ■The Characteristics of Pulp Fibers From Agricultural Residues," TAPPI. (Nov. 1952), 62A-68A.

7*# , Aronovsky, S. I*, Naffziger, T. R., "Increased Profits froa Cane Sugar By-products," The Sugar Journal, 14, (June 1951), 10-33.

75• » Industrial Utilization of Sugarcane Bagasse," The Sugar Journal, 10. (Nov. 1947), 5-13.

76. , "Sugar Cane Bagasse Utilization," Chemical Digest. 8, (June 1949), 12-16.

77. Liu, K. H., "Bagasse Pith Proves Efficient Fuel in Taiwan Sugar Factory," Sugar, 50. (Jan. 1955), 47.

78. Lorenzi, 0. de, nSone Thoughts on Bagasse Burning," The Sugar Journal. 17, (Oct. 1954), 16.

79. Love, T., "Steam Generating In Louisiana Factories," The Sugar Journal, 12, (March 1950), 11-12.

80. Lynch, D. F. J., and Goss, M. J., "Bagasse Cellulose," Ind. Big. Chen., 24, (Nov. 1932), 1249-1254.

81. Martin, L. F., "Utilization of By-products of Louisiana Sugar Cane," S ugar, .13. (May 1951), 46-52.

82. McCulloch, A. F«, "A Review of Bagasse Fuel Quality Trends and of Recent Boiler Efficiency Tests, " Proc. 27th Annual Congress South African Technical Assoc.

83. Mehendale, S. G., "Glass from Bagasse," Trans. Indian Ceram. Soc.. 6, No. 67 (19 4 7 ), 67. “ ~

84. Mendes, A. S., "Possibilities of Sugar Cane Bagasse as a Rav Material for Cellulose," Rev. Quin. Ind.. 22, No. 251, (1953), 14-16.

85. "Milk Coaiposition in Relation to Quantity of Bagasse in Ration," Moloch Proaysh, 12, No. 11, (Nov. 1951), 28.

86. M iller, E. C., "The Spreader-Stoker in the Sugar Factory," International Sugar Journal. LVI. (Aug. 1954), 221.

87. "Molasses, The Roughage Buster," The Sugar Journal. 17, (Sept. 1954).

88. Molitor, John B., "Industrial By-products from Sugar Cane," The Sugar Journal, 11, (March 1949), 24. 150

89. Naidenov, A. K., "On Bagasse Drying in Sugar Factories," Sakh Proaysh, 25, (Jan. 1951), 25-28.

90. Naffziber, T. R., »»Feed Evaluation," J. Agri. Food Chen.. 1, (1953), 847-851.

91. 0timer, D. F., and Femstora, G. A., "Destructive Distillation of Bagasse," Ind. and Big. Chen.» 35. (1943), 312.

92. Peres, Alosi, S., "The Relation Between Fiber Percent Cane and Moisture in Bagasse," Assoc, de Tech. Asucareros de Cuba, 24, (1950), 417-421.

93. Perila, 0., "Fine Paper Pulp from Bagasse," Paperi ja, Pau, Papper Och Tra (Paper and Timber, Finland), 35, (1953), 29-34.

94. Perk, C. G. M., "Calorific Value of Bagasse." International Sugar Journal. LV, (1954), 312-314. "

95. , "Calorific Value of Bagasse," South African Sugar Journal, 35, (1951), 697-703.

96. Puig, I. L«, "The Spreadcr-Stoker," International Sugar Journal, LVI, (March 1954), 75.

97. Schmidt, 0., et al, "Rapid Analysis of Bagasse," International Sugar Journal, 55, (1953), 41-44. ”

98. Shillington, A. F., "The Economical Combustion of Bagasse," Interna tional Sugar Journal, XLI, (July 1939), 258.

99. Shimidu, T., "Decolorizing Carbon fro* Bagasse," J. Soc. Trup Agr.. 15, (1943), 201-205. ““

100. Stevens, G. de, and Nord, F. F., "Cellulose Degradation and Lignin Composition in Bagasse," American Chemical Society Journal, 74. (July 5, 1952), 3326-3328. *”*

101. Sugar Journal, Annual Number, June 15, 1954.

102. Tabb, C. B., "The Place of Agricultural Residues in Paper Making Today,11 Chcm. and Ind., (1952), 960-964.

103. "Utilisation of Vaste Bagasse from Sugar Cane," Pacific Plastic, 10. (Oct. 1948), 20-22. "

104. Vaquez, A. E., "Products from Sugar Cane and Processes for Obtaining Them," Abstract, Sugar, 42, (Nov. 1947), 53. 151

105. Vaquez, A* E., "New Methods of Using the Residues of the Cane Sugar Industry,* Proceedings, 24th Annual Conf• Assoc. Tech. Azucar, Cuba, (1950), 501-518.

106. Vasil'ev, I. P., "Bagasse Shipping at Novo-Tavelehanski Sugar Factory," Sakh Promysh, 25, (May 1952), 34*

107. Wells, S. £., and‘Atchison, J. E., "Production of Pulp from the Fibrous Elements of Sugar Cane Bagasse," Paper Trade Journal, 112, (March 27, 1941), 162-166.

108. Wiggins, L. F., Proceedings of the 8th Congress of the International Society of Sugar Cane TecEnoIogiata, (1953). p. 645.

109. ______, "Sugar Cane as a Source of Industrial Chemicals and M aterials," The Sugar Journal, 16. (Jan. 1954), 22-25.

. "Survey of the Work of the BWI Sugar Research Scheme, " In ternational Sugar Journal, LIV, (Dec. 1952), 326.

111. Williams, A. E., Fibres, Natural and Synthetic, 15, (July 1954), p. 219.

112. Wilson, P. D., "Bagasse as a Fuel for Steam Generation," The Sugar Journal. 17, (July 1954), 15-20.

113. Yove, K. J., "Investigations Into the Unbumt Bagasse Nuisance," Queensland Soc. Sugar Cane Tech., 18, (1951), 129-139.

114. Zanni, V., El Bagazo de la Cana y sus Aplicaciones Industrieles Azucar, 1, (jan.T946), 31, 33-39.

115. Zerban, F. W., System of Cane Sugar Factor Control of the International Society of Sugar Cane Technologists, New York: Published by £ugarT" 152

116. Aljian, G., By-Products Research Program. Report to Hawaiian Sugar Planters Assoc., Dec. 1954.

117. Atchison, J. E., "Factors Influencing the Selection of Processes and Choice of Equipment for Bagasse Pulp Manufacture," copy of paper presented at the Latin-American Meeting of Experts on the Pulp and Paper Industry held Oct. 1954, at Buenos Aires, Published by Parsons and Whittmore, Inc., N. Y.

118. Nordfelt, S., "Chemically Treated Cane Bagasse for Cattle Feed," Hawaii Agricultural Experiment Station Progress Note 69, Aug. 1951.

119. Wayman, 0., Iwanaga, I., et al, Fattening Steers on Sugar Cane By-Products, Bulletin, University of Hawaii Agricultural Experiment Station, Dec. 1953.

1 2 0 . Wayman, 0«, Leong, K. C., "Sugar By-Products Show Promise as Swine Feed," Hawaii Farm Science. April 1953, pp. 4-6. 1 2 1 . Wayman, 0 ., Iwanaga, I., "Sugar Cane By-Products as Major Constituents of Rations for Dairy Heifers, Milking Cows, and Beef Steers.11 Hawaii Agricultural Experiment Station Progress Note 84. Oct. 1952.

122. Won, Y., "Production of Furfural from Bagasse," Report Taiwan Sugar Experiment Station. No. 7, (1951), 164-171.

123. Yann, T. L«, "Bagasse Composts," Report Taiwan Sugar Experiment Station. No. 6, (1950), 250-255.

124. Yee Hu, Teh Ching Chow, "Pulping Bagasse by Calcium Sulfite Process," Reprint of The Taiwan Sugar Experiment Station. Report No. 2, Dec.

125. . "Pulping Bagasse by Alkaline-Chlorine Process, I", Reprint of Ihe~Taiwan Sugar Experiment Station. Report No. 3, Dec. 1948.

126. . "Pulping Bagasse by Alkaline-Chlorine Process, II," Reprint of The Taiwan Sugar Experiment Station, Report No. 5, Dec. 1949.

127. Yee Hu, K. Shen-T'u, and Weng-Ching Hsich, "Pulping Bagasse by Alkaline Chlorine Process (III)," Reprint from Report of The Taiwan Sugar Experiment Station. Report No. 8, June 1952.

128. Yee Hu, Weng-Ching Hsich, and Chien Tc Yang, "Alpha-Cellulose from Ba gasse by Alkaline-Chlorine Process (1)," Reprint from the Taiwan Sugar Experiment Station. Report No. 9, Dec. 1948. 153

129. Yee Hu, Vunchi Chang, ”A Study on the Celotex (1)," Reprint of The Taiwan Sugar Experiment Station. Report No. 3, Dec. 1948.

130. Yee Hu, Teh»Ching Chow, "A Preliminary Report on Pulping Bagasse Vith Butanol,” Reprint of The Taiwan Sugar Experiment Station. 154

(d) Louisiana State University Theses and Chemical Engineering Projects

131. Allen, P. E., et al, Sugar Cane Bagasse Processing. Louisiana State University Chemical Engineer ing Scnior Project Report, 1952.

132. Arnold, T. H., Bagasse Furnaces. Louisiana State University Chemical Engineering Course CHE 270, Jan. 22, 1953.

133. Bennett, N., The Fermentation of Bagasse. Louisiana State University Chemical Engineering Department Thesis, 1926.

134. Brubaker, P. E., et al, The Bagasse Processing Pilot Plant. Louisiana State University Chemical Engineering Senior Project Report, 1952.

135. Colvin, C. E., and Hanesvorth, S. D., Sugar Cane Bagasse Separation Project. Louisiana State University Cnemical I&iginccring Senior Project Report, 1954.

136. Fontaine, M. F. R., Sugar Cane Bagasse Processing. Louisiana State University Chemical Engineering Department Thesis, 1951.

137. Frantx, J. F., et al, Bagasse Separation into Pith and Fiber. Louisiana State University Chemical Engineering Senior Project Report, 1954.

138. Gilmore, V. H., and Mora, M., Bagasse Drying Project. Louisiana State University Chemical Engineering Senior Project Report, 1954.

139. Gregory, R., et al, Valentine Pulp and Paper Co., Lockport, La. Senior Chemical Engineering Report, Louisiana State University, March 1955.

140. Kalbrook, K. 0., et al,. Bagasse Separation Manual of Operation. Louisiana State University Chemical Engineering Department, Supplemented by Frantz, J. F., et al, 1954.

141. , Sugar Cane Bagasse Separation Project. Louisiana State Uni versity Chemical Engineering Senior Project Report, 1954.

142. Kramer, V. A., A Study of Cane Bagasse. Louisiana State University Chemical Engineering Department Thesis, 1925.

143. Linder, T. E., Sugar Cane Bagasse U tilization. Louisiana State Univer sity Chemical Engineering Department Thesis, 1950.

144. Literature Survey of the Mechanical Separation of Bagasse. Louisiana State University Chemical Engineering Department. 155

145. McCombs, G., et al, Bagasse Separation Into Pith and Fiber. Louisiana State University Chemical i£igincering Senior Project Report, 1953.

146. Norton, J* S ., Characteristics of Res in-Bonded Bagasse Building Board. Louisiana State UniversityChemical Engineering Department Thesis, 1950.

147. Reedy, F., A Study of Bagasse. Louisiana State University Chemical Engineering Department Thesis, 1932.

148. Rogers, F. W., et al, Sugar Cane Bagasse Separation Project. Louisiana State University Chemical Engineering Senior Project Report, 1952.

149. Stokes, J. D., Pulping of Bagasse with Nitric Acid. Louisiana State University Chemical Engineering Department Thesis, 1952.

150. Thibaut, J. H., Bagasse. Louisiana State University Chemical Engine ering Department Thesis, 1942.

151. Westbrook, E. J», et al, Bagasse Separation Project. Louisiana State University Chemical Engineering Senior Project Report, 1951. 15b

(f) Pamphlets and Single Sheets

152. Bago-Molasses, A Cattle Feed, Government of India, Ministry of Food and Agriculture, Indian Institute of Sugar Technology, Ut..Kanpur.

153. Current Uses of Furfural, Bulletin 202 and 204, The Quaker Oats Co. Chemical Dept.,""Chicago, 111.

154. Florate Leaflet, Codchaux Sugars, Inc., New Orleans, La.

155. Cilg, F. X., Utilizing Bagasse as Fuel, Bulletin 3-414. The Babcock and Wilcox Co., New York, N. Y.

15b. Grayson, W. M., Recapitulation of Final Manufacturing Reports of Louisiana. Prepared by Grayson, Sugar Marketing Specialist, La. State ASC Office, Crop of 1953-54.

157. , Recapitulation of Final Manufacturing Reports of Louisiana. Prepared by Grayson, Sugar Marketing Specialist, La. State ASC Office, Crop of 1952-53.

158. Manufacture of Activated Carbons, Government of India, Ministry of Food and Agriculture, Indian Institute of Sugar Technology, Dt. Kanpur.

159. Servall-Stazdry Leaflet, Godchaux Sugars, Inc., New Orleans, La. 157

(e) Patents

lbO. Freeman, L,, Clarification of Settling Liquors, U. S. Patent No, 2,500,065, March 7, 1950,

161. Fuller, C, W., Apparatus for Drying Bagasse, U. S. Patent No, 2,481,305, Sept, 6, 1949,

162. Horton, P. M., and Keller, A. G, Methods of Separating Sugar Juice, Pith, and Fiber from S ta lk s , U. S. Patent No. 2,650,17b, Aug. 25, 1953,

163. Koree, J. U., Tobacco Substitute Containing Bagasse, U. S. Patent No. 2,576,021, Nov. 20, 1951.

164. McElhinncy, T. R., Synthetic Resin and Process of Making Same, U. S. Patent No. 2,394,000, Feb. 5, 194b.

165. Roman, C ., A r tif ic ia l Wood Product and Methods of Making the Same, U. S . Patent No. 2,578,489, Dec. 11, 1951.

16b. Rosa, Sr., J. J. de la, Continuous Digestion Apparatus for the Production of Highly Purified Cellulose, U. S. Patent No. 2,542,801, Feb. 20, 1951.

167. Sweeney, 0. U., et al, Production of Lignin, Cellulose and Pentosans, U. S. Patent No. 2,615,883, Oct. 28, 1952. 158

(g) Letters

168. Atchison, J. E., letter to A. G. Keller, Feb. 18, 1954.

169. Atchison, J. E., letter to R. M. Hansen, Aug. 24, 1954.

170. Atchison, J. E., letter to R. M. Hansen, Feb. 3, 1955.

171. Brinkley, A. V., letter to G. W. Gilbert, Jan. 15, 1954.

172. Chapman, A. W., l e t t e r to R. M. Hansen, Feb. 26, 1954.

173. Chapman, A. V ., l e t t e r to A. G. K e lle r, O ct. 15, 1954.

174. Chidester, C. H., letter to R. M. Hansen, Mar. 1, 1953.

175. Cook, T. H., letter to R. M. Hansen, Sept. 2, 1954.

176. Goss, J. J., letter to A. G. Keller, Jan* 29, 1954.

177. Humbert, R. P., letter to R. M. Hansen, Sept. 8, 1954.

178. Lathrop, E. C., letter to R. M. Hansen, Mar. 2, 1954.

179. Mabrey, G. S., letter to A. G. Keller, Jan. 18, 1954.

180. Mabrey, G. S., letter to A. G. Keller, Jan. 29, 1954.

181. McCarthy, R., letter to R. M. Hansen, Mar. 7, 1955.

182. MacLaurin, D. J., letter to R. M. Hansen, Feb. 26, 1954.

183. Shuker, H. V., letter to R. M. Hansen, Aug. 20, 1954.

184. Wayman, 0., letter to R. M. Hansen, May 20, 1954. APPENDIX I . ECONOMICS OF A BAGASSE SEPARATION PLANT

The following analysis is based on a commercial size Bagasse

Separation Plant having a capacity of ten times that of the experimental unit covered in this dissertation. Calculations arc made for both a 55 day and a 130 day operating season.

Cost of Plant $100,000 (Amortized at 10# per year)

Maintenance $2,500/ycar for 55 day season

$3,500/year for 130 day season

Electricity 0.9 cents per KWH

Water 2 cents per 1000 gals.

Bagasse $2.50 per dry ton of fiber

Bagasse ash to average 5#

Ash to be reduced to 1.5#

Average Moisture of Bagasse 50#

Bagasse to yield 60# f ib e r

Bagasse rate assumed to average 17,000 lbs. of dry bagasse per hour.

Labor - operator $1.75 per hour; helper $1.00 per hour.

No. 1 mill to operate dry to recover pith.

No. 2 and 3 mills to operate wet.

A 12# lost time factor is assumed.

Case I - b5 crop days.

Case II - 130 crop days.

150 161

Cost of Bagasse Processed

Case I

17.000 lbs/hr. x 24 hrs./day.x 0.88 days/day x 65 days « 23,337,600 lbs.

22 0 ^Y bV ton3'~ x $2.50 per top - $29,172

Case I I

17.000 lbs/hr. x 24 hrs./day x 0.88 days/day x 130 days * 46,675,200 lbs.

lh S ' * $2.50 per ton * $58,344 2000 lbs/ton

Pover Costs

From Fig. 7, using 3400 lbs. of wet bagasse per hour, the power consumption

is 0.0075 KWI^lb. of wet bagasse or 0.015 KWH/lb. of dry bagasse.

Case I

0.015 KWH/lb. x $0.09 per KWH x 23,337,600 - $3,151

Case I I

0.015 KWH/lb. x $0.09 p er KWH x 46,675,200 - $6,302

Water Costs

From Fig. 12, for 1.5£ ash in the fiber, it is necessary to use 400 lbs. of water per lb. of ash in the feed.

Case I

400 lbs/lb x .05 ash x .12 gal/lb. x 23,337,600 lbs. - 56,000,000 gals.

$0.02 per 1000 gals, x 56,000 * $1,120 162

Case I I

400 lbs./lb. x .05 ash x .12 gal/lb. x 46,675,200 lbs. - 112,000,000 gals.

$0.02 per 1000 gals, x 112,000 - $2,240.

Labor Costs

Case I

$2.75 per hour x 24 hrs./day x 65 days ** $4,290

Case I I

$2.75 per hour x 24 hrs./day x 130 days * $8,580

Fiber Production

Case I

•60 x 23*337,600 lbs. B 7 , 0 0 1 to n s 2000 lbs/ton

Case I I

.60 x —j-Jz-L-. » 14,003 tons 2000 lbs/ton

Pith Production

From Table XII, it can be seen that at least 1/2 of the pith produced will be removed in the No. 1 m ill. The moisture content of this pith is essen

tially the same as that of the bagasse since no water is used in the No. 1 m ill. At $2.50 per dry ton, which is the cost of the bagasse, the pith

from the No. 1 mill is worth:

Case I

.40 x . 4 668 tons of pith, total 2000 lbs/ton 1/2 x 4,668 x $2.50 per ton “ $5,835 163

Case I I •40 x 46,675,200 ibg. B 9,335 tons of pith, total 2000 lbs/ton

1/2 x 9,335 x $2.50 per ton ■ $11,669

Cost of Plant Operations

Case I Case II T o ta l Cost $/ton of fiber Total Cost $ /to n o f

Depreciation $ 10,000 $ 1.43 $ 10,000 $ 0.71 Maintenance 2,500 0.36 3,500 0.25 Pover 3,151 0.45 6,302 0.45 Water 1,120 0.16 2,240 0.16 Labor 4,290 0.61 8,580 0.61 4 21,060 4 3.01 $ 30,622 4 2.18

Cost of Fiber

Case I Case i i T o tal Cost $/ton of fiber Total Cost $/ton of ;

Bagasse $ 29,172 $ 4.17 $ 58,344 $ 4.17 Less value of pith 5,835 0.83 1,669 from No. 1 m ill 0.83 $ 23,337 4 3.34 $ 46,675 4 3.34

O peration 21,060 3.01 30,622 2.18

Total cost of Fiber $ 44,397 4 6.35 $ 77,279 $ 5.52 $44 397 7 001 tons " $6*35 P*r ton ot fiber for a 65 day operating season

$92.150 $5.52 per ton of dry fiber for a 130 day operating season 14,003 Tons

It should be mentioned that for some types of paper and vail board a yield of fiber higher than 60JS of the bagasse feed vould be permitted. This vould further reduce the cost of the fiber.

In ordinary cossoercial practice, wall board manufacturers indicate that for every 100 tons of bagasse purchased, about 70 to 75 tons is pre sent in the finished product. Because of this, the actual rav material 164

c o s t i s n o t $2.50 per to n , but sorae.what hig h e r. I t i s th e a u th o r 's opinion that the depithed material vould not be subject to the same losses as the whole bagasse. Since the amount of separation obtained in the Bagasse Separation Plant can be adjusted to any amount desired, it vould be of ad vantage for the wall board manufacturer to use a dcpithed rav material to both reduce his losses and obtain fiber particles vith a higher length to diameter ratio.

* 1 1 . DEFINITIONS^70)

(1) Cane - The raw material delivered at the factory, including clean

cane, field trash, water, etc.

(2) Field Trash - The leaves, tops, dead stalks, roots, soil, etc., de

livered at the factory with the clean cane.

(3) Fiber - The dry, water-insoluble matter in the cane.

(4) Normal Weight - The weight of sample equal to that weight of pure

sucrose which, when dissolved in water to a total volume of 100

ml at 20*C, gives a solution reading 100 degrees of the Inter

national Sugar Scale when examined in a saccharimeter, in a tube

200 nm long, at 20*C.

(5) Pol - The value determined by direct or single polarisation of the

normal weight solution in a saccharimeter. The term is used in

calculations as if it were a real substance.

(6) Sucrose - The disccharide known in chemistry as saccharose or cane

sugar (C i 2 H2 2 ° l l ) •

(7) Brix - The per cent by weight of solid matter, as indicated by a

■Brix* spindle or other densimetric device.

(8) Gravity Solids - The weight of solids calculated from the Brix

determinations.

(9) Purity - The percentage of Pol in the Brix of Gravity Solids.

(10) Undiluted Juice - The juice expressed by the mills or retained in the

bagasse, corrected for imbibition water.

165 166

(11) Last Mill Juice - The juice expressed by the last mill of the tandem.

(12) Last Expressed Juice - The juice expressed by the last two rollers of

the tandem.

(13) Mixed Juice - The juice sent from the crushing plant to the boiling

house*

(14) Bagasse - The Residue obtained from crushing cane in one or more

m ills. Known respectively as First m ill bagasse, Second mill ba

gasse, etc., and as Last mill bagasse, or Final bagasse, or simply

bagasse, when the material from the last mill is mentioned.

(15) Residual Juice - The juice left in the bagasse; bagasse minus fiber.

(16) Imbibition - The process in which water or juice is put on the ba

gasse to mix with and dilute the juice present in the latter. The

water so used is tensed imbibition water.

(17) Maceration - The process in which the bagasse is steeped in an ex

cess of water or juice, generally at a high temperature. The water

so used is tensed maceration water.

(18) Dilution Water - That portion of the imbibition or maceration water

present in the mixed juice. ABBREVIATIONS

KWH - - - - Kilowatt-hour

KW - - - - Kilowatt

HP - - - - Horse Power

RPM - - - - Revolutions per minute

F ig .- — — — Figure

Lb. - - - - Pound

LSU - - - - Louisiana State University

Hr. - - - - Hour

Min.- - - - Minute ii — - - - inches i - - - — — Feet

Ft. - - - - Feet or Foot p.- - - - - page x axis - - Horizontal axis or abscissor y axis - - Vertical axis or ordinate

No. - - - - Nunber i.d .- - - - Inside Diameter

Cont'd. - - Continued

B .D .- - - - Bone Dry, co n ta in in g no m o istu re

MCF - - - - 1000 cubic feet

167 I I I . SUMMARY OF CALCULATIONS

A. M aterial Balance

The following set of sample data and calculations arc included so that one may better understand the results reported in this investigation.

One Factor that has not been explained or is not self explanatory is the 68 pounds of pith reported as assumed loss (p. 173). This figure is actually 5# of the dry bagasse feed and was established by a water balance around the Bagasse Separation Plant. This loss factor became n ecessary when a change was made from weighing th e fib e r during th e 1952 season to weighing the pith in the '53 and '54 seasons. The following is the Basic Material Balance:

Fiber + Pith ♦ Solids lost in drain water n Feed

If the Feed and Fiber are weighed, then the Pith and Solids in the drain water can be combined into one term and called Pith. However, if the Pith and Feed are weighed, the Solids in the drain water becomes an important item since it is the Fiber that is of most importance. The quantity of water going to the drain is not known since so much of it goes out in the fiber and pith. A water balance is necessary.

Water injected in mills ♦ water in Bagasse = Water in Pith + Water in Fiber ♦ Water to the Drain.

For the sample data:

Water injected » 17,640 lbs. Water in Bagasse *» 2780 x .513 «• 1.400 lbs. Total entering 19,040 lbs.

168 169

Water in Pith from No. 1 Hill ** 454 x .504 “ 229

Water in Pith from No. 2 and 3 Mills » 1996 x .896 g 1,785

Total in Pith 2,014 lbs.

The water in the fiber needs to be calculated. This is done by m ak in g an assumption of the amount of solids passing down the drain:

First Assumption for Solids

Water injected x solids ** 17,640 x .0091 a 160 lbs. of solids; then

Water in Fiber =« lbs* dry feed " lbs* *** pith ~ lbs> dry solids to drain fraction dry fiber

x Fraction H 2O in F ib er o 1354 - 433 -160 x Q3 m 3?20 .17

The amount of drain water Can now be calculated:

19,040 » 2,014 + 3,720 + drain water

13,306 lbs. a drain water

Second Assumption for Solids

13,306 x .0091 0 121 lbs. solids

Water in Fiber - ^-i.345. ", .^ 3 T.121 x .83 - 3,910

19,040 - 2,014 ♦ 3,910 ♦ drain water

Drain Water B 13,116 lbs.

Third Assumption of Solids

13,116 x .0091 a 119 lbs. solids

This 119 lbs. is very close to the second assumption which gave 121 lbs. 170

This figure is about 9% of the feed. The reason that it is high is that,

at high water rates, Btuch water was drained from the fiber strainer tank

and fiber product tank which was not sampled, because the discharge was

inaccesible. This water was noticeably cleaner than that from the pith

strainer tank. At the lower water rates, nearly all the water was dis

charged from the pith strainer tanks, therefore, the figures for solids

lost down the drain on these ruis are more accurate* Below is a summary

of the check that was made:

Run No. Per Cent of Feed l b . w ater Lost in Brain Water l b . Jeed

C-54-2 5 .0 6.70

3 2.3 4.70

4 3.7 6.70

5 12.0 15.90

6 6 .4 8.70

8 11.9 11.40

9 5 .0 4.13

10 2.3 5.33

11 5 .0 8.45

12 2.7 11.20

13 8 .6 15.12

14 7.3 17.56

Awerage, discarding 4.6% ru n s 5 and 8

Actually, whether a 4, 5 or 6 per cent loss was assuned, it would not affect the results significantly. This assumption was made so that the 171

fiber to feed ratio vould be more accurate and not over estimated. An

other way to account for the 5 per cent loss vould be to assuae that the

raw bagasse contained 5 per cent soluble solids and that all of these vere

removed on the vet runs. This vould not be a false assumption considering

that bagapse is purchased in Louisiana on the basis of 6 per cent soluble

solids if analyses arc not made.

Fontaine^*) reported a figure of approximately 5 per cent of the feed as lost by veighing both the fiber and the pith and determining their m o istu re s.

For the runs in vhich no water was used on the m ills, the loss factor was considered to be zero. Actually, there may have been spillages amount ing to one or two per cent. B. Sample Data and Calculations Run No. - F-54-o

TIME OF RUN:

Time of Stopping 2:23

Time o f S ta rtin g 1:21

Time Elapsed 62 min.

POWER USED:

K-W Meter Reading a t End of Run 324.0

K-W Meter Reading at S tart of Run 308.9

K-W Hours Used (N x 1*5) 1.5 x 15.1 ** 22.7

WATER USED:

Meter Reading at End of Run 32,840

Meter Reading at Start of Run 31,076

Water Used 1,764 » 17,640 lbs.

BAGASSE ON BONE DRY BASIS:

Net Weight of Wet Feed Bagasse 2,780

Weight of Bone Dry Feed 1,354

Bone Dry Feed Rate 1,310 lbs/hr

Wet Feed Rate 2,690 lbs/hr A FIBER ON BONE DRY BASIS:

Net Weight of Wet Fiber 5,050

Weight of Bone Dry F ib er 853

Bone Dry F ib er Rate 825 lb s A r

v 172 1 7 3 !

PITH: “ NO. 1 Hill NO. 2+3 Mill Loss ______T o ta l

Net Weight o f Wet P ith 454 1,996 Assumed

Weight of Bone Dry Pith 225 ______208 ______68 ______501,

% P ith Removed in M ill #1 45

Fiber/Feed Ratio (Bone Dry) 0.63

K-W Hours Used/Weight Bone Dry Feed 0.167

K-W Hours Used/Weight Bone Dry Fiber 0.0266 KWH/lb.

Weight Water Used/Weight Bone Dry Feed 13.0 lbs/lb.

Weight Water Used/Weight Bone Dry Fiber 20.6 lbs/lb.

Weight of Desirables —

Weight of Undesirables —

P er Cent Feed Removed As P ith 36.8

Per Cent Desirables —

Per Cent Feed Removed No. 1 M ill 16.6

No. 1 Mill Dry

No. 2 M ill Wet

No. 3 M ill Wet 174

DATA AND CALCULATIONS

Run No. - F-54-6

MOISTURE CONTENT; BAGASSE FIBER PITH No. 2 - 3 No. 1 M ill M ills

Sample Weight 100.0 200.0 100.0 200.0

Total Wt. After Drying 48.7 34.0 49.6 20.8

Total Moisture Lost 51.3 166.0 50.4 179.2

Per Cent Moisture 51.3 83.0 50.4 89.6

P er Cent Bone Dry Sample 48.7 17.0 49.6 10.4

SUCROSE CONTENT:

Sample Weight 100.0

Total Wt. After Digest 1,100

Capsule Weight

Wt. of Bagasse Plus Extract 1,100

Weight of Fiber 49

Weight of Extract 1,051

Polarization (in 400 ran tube) 2.6

From S ch m itz's Table 0.33

Suc.(pol) in Solution 0.33

Sue. in Bag. ^ x 3 .4 7 100

BAGASSE DATA:

Date Ground - 11-4-54

Type Cane - Alma and St. Gabriel 175

FIBER DOfSITY Run No. - F-54-b

Tare and Wet Fiber 473.7

Tare 87.0

Weight o f Wet F ib er 386.7

1 - (Moisture) ■ 0.17

Weight of Dry Fiber 65.7

Distance from top edge (Measured) 3 -3/4 5-7/8 6-7/8 7-7/8 3-5/8 5-7/8 7 -1/4 8-1 /4 3 -1/2 5-1/2 7 -1/2 7-7/8 3-1 /2 5 -1/2 7-1/4 8 -1 /4

Distance from top edge 5-1/8 7-1/4 8-3 /4 9 -1 /2 (Average ♦ lid)

Distance from bottom 32 26-7/8 24-3/4 23-1/4 22-1/2

Volume, ft3 18.1 15.2 14.0 13.1 12.7

Density, lbs/ft^ 3.63 4.32 4.69 5.02 5.17

Total Weight 0 218 370 541 727 l b s . / f t 2 32.1 54.5 79.7 107.2

PARTICLE SIZE FIBER

1/2'» 32.6#

1 /2 « •- l»t 29.7$

1" - 1-1/2" 8.8$ •

1-1/2»• - 2" 14.8$

2" - 2-1/2# 2.3$ 2- 1/ 2 # ♦ 1 1 . 7 $ 176

ASH ANALYSES Run No. - F-54-6

BACASSE 1 2 3

Tare and Bagasse 80.2345 83.6415 71.4226

Tare 73.4593 78.0561 64.7517

Wt. of B.D. Bagasse 6.7752 5.5854 6.6709

Tare and Ash 73.8555 78.4129 65.2062

Wt. o f Ash 0.3962 0.3568 0.4545

% Ash in Bagasse 5.84 - 6.39 6.81

Average 6.35

FIBER

Tare and Fiber 90.2165

Tare 85.6306

Wt. of B.D. Fiber 4.5859

Tare and Ash 85.7079

Wt. of Ash 0.0773

% Ash in Fiber 1.69

SOUPS IN DRAIN WATER MUD

Tare ♦ Water 274.6 Total Volisne 1000 ml

Tare 83.7960 Mud after 24 hrs. 130 ml

Solids + Water 190.8 % Mud 13*

Tare ♦ Solids 85.5280

Tare 83.7960

S o lid s 1.732

% Solids » 1.732/190.8 x 100 « 0.91* C. STATISTICAL CALCULATIONS

The past few years have seat the development of a new approach to many types of experimentation. This development has been based on prob ability theory and the techniques have become loosely known as statistical methods. The original developments in this field were motivated by experi mentation in the biological, agricultural and social science fields. The

first industrial application of probability theory was in the well known field of quality control.

The primary contribution of statistical methods to the chemical field is in the methods for extracting correlations from data containing dependent and independent variables (for instance, yield vs feed rate) and in the methods for designing experiments. Engineers have developed a fa cility for extracting information from their data, often times by awkward means, and have not, in general, gained an appreciation of statistical methods. For these reasons, an attempt was made in this dissertation to apply some of the most widely accepted methods to the design of experiments and the determination of cause and effect relationships.

Use was made of correlation coefficients and regression equations.

These two items, although called by different names, are calculated simultaneously due to the sim ilarity of the methods. Use was also made of analysis of variance techniques which aid in the design of experiments.

177 178

1. Regression Equations

This is used to predict the most likely measurement in one variable from the known measurement in another*

Sample Data

Run No. X (independent variable) Y (dependent variable)

1 14.3 10.8 £ = sum 2 12.8 11.4 X = measured value 3 12.7 13.0 X 3 Mean of inde 4 10.6 14.6 pendent variable 5 10.7 13.6 x » X - X 6 13.0 12.2 Y *' measured value 7 14.4 10.7 2 * Mean of dependent 8 12.5 12.8 v a ria b le 9 8.7 16.2 y - Y - 2 10 12.2 11.8

Sum 121.9 127.3

X » 12.19 Y - 12.73

Regression Coefficient = b ■ Slope of the straight line of best fit b - number of units change in a dependent variable for each unit of in crease in an independent variable. b » change in Y unit change in X b is either + or -

Since: £ (X - X ) 2 - £ x* - EX2 -

£ (X - X) (Y - 7) ■ E xy * £XY - b » ^ Y - (S( £Y)/N „ -26.33 * ..95 £ X2 - (£X)tyN 27.65 b is the slope of the straight line which best fits the data; that is, the line where the sum of squares of the deviations is at a minimum. 179

To fin d p o in ts to p lo t:

Y = b x + A

A » 7 - b£

A » 12.73 ♦ .95 x 12.19 - 24.31

Y - 24.31 - .95x

F or X - 8 Y « l b . 71

For X - 15 Y “ 10.06

These two points are then plotted on rectangular coordinates and the line drawn between them is the one which best fits the above sample data. The judgement as to whether a cause and effect relation exists is not statistical.

2. Correlation Coefficient, r,

The Value of r ranges from +1 to -1

♦1 indicates perfect proportionality.

-1 indicates perfect inverse relationship.

0.0 indicates no relationship between two variables. r is then a measure of the extent of relationship between two variables.

EX2 - - E (14.3)2 ♦ ....+ (1 2 .2 )2 - (A21*9) 2 »" 27. 27.65 10

- 27.52

121.9 x 127.3 EXY - o e ( 1 4 . 3 x io ,8 ) ♦.... + (12.2 x 11.8) - 10 = -26.33 180

r ------——— ------* ~?6*33 > -.955 27.65 x 27.52 27*58

To determine degrees of freedom (df):

df ■ N - No. of Variables where N equals the number of sets of data.

10-2-8 degrees of freedom.

From Table VI, page 408, Reference 3:

r fo r 5% level => .632

r fo r \% level *» .765

Since the calculated r in the above case is .955 and larger than .765, the correlation is significant at the 1 per cent level. r^ - (-.955)^ - .912 or 91$ of the variation which occurs in Y was accounted

for by association with X.

For r equal to

Less than .20 - slight; almost negligible relationship.

.20 to .40 - Low correlation; definite but small relation.

.40 to .70 - Moderate correlation; substantial relation.

.70 to .90 - High correlation; marked relationship.

.90 to 1.00 - Very high correlation; very dependable relation.

Due consideration should be given to the degrees of freedom when evaluating the meaning of the correlation coefficient. One may sec in the sample table how the value of the correlation coefficient, which is required to be significant, varies with the number of degrees of freedom.

i 181

Sample of Significant r Values

Degrees of Freedom S% Level 1% Level

1 0.997 1.000

3 0.878 0.959

5 0.754 0.874

8 0.632 0.765

15 0.482 0.606

50 0.273 0.354

The values of r which constitute the 1 per cent and 5 per cent

levels of confidence have been tabulated (page 610, Reference b). That

is, if no real correlation existed between two variables and data were

taken and the correlation attempted 100 times an r value equal to or greater than the stated amounts for the 5 per cent and 1 per cent levels would be expected 5 times and 1 time, respectively. When an r greater

than the 1 per cent level is obtained one may then say that he is 99 per

cent sure that the correlation really exists.

3. Analysis of Variance

The analysis of variance is not a mathematical theorem, but rather a convenient method of arranging the arithmetic. Just as in arithmetical

text books, rules are given on how to work out a sum, so it is with the analysis of variance. It is convenient in two ways: (1) it brings to ones attention a mass of data in which the content of the whole is readily ap preciated. Probably everyone who has used the analysis of variance lias found that comparisons which were not previously apparent, are made obvious, 1 8 2

because they are necessary items of the analysis* (2) It is convenient in facilitating and reducing to a common form all of the tests of signif icance which one may want to apply.

The test of significance in connection with the analysis of variance is designed to say whether or not sets of data are sufficiently different from one another to reject or accept the hypothesis that these differences were caused by random sampling from the same population.

The total sum of squares is based upon the deviations of ail values in the analysis about the mean of all the values.

The stsn of squares within groups is based upon the deviations of the various measures from the means of the samples of which they are a part.

The sum of squares between groups is based upon the deviations of the means of the various samples from the mean of the combined samples.

In the first example below the total variance has been divided into two parts* the between column variance and the within column variance. The second example is the same as the first except the total variance has been divided into three parts* the between column variance* the between row variance and the residual. The columns are assumed to be variations in one experimental variable and the rows to be variations in another variable.

Sample Calculation of Analysis of Variance (Reference 3* page 274)

Columns 1___ 2 3 4 5 Sum A 18 20 20 21 21 100 Rows B T7 19 19 20 20 95 C 16 17 18 19 20 90 (continued on n e x t page) 183

Sample Calculation of Analysis of Variance (Continued) Columns 1 2 3 4 5 Sum ...... D 1 b ' "T b — 17 i s 18 85 Rows £ lb lb 15 i i l b 80 Sum 83 88 89 95 95 450

To divide the total variance into two parts, one makes the following calculations:

Total (18)2 + (17)2 + (ifc)2 +.... + ( lb ) 2 - » 78.00 I s

Columns iSJ ) 1 ♦ ♦ iS2l2 ♦ iSSl! ♦ i2Sl5 - „ 2 0 .Q0 ------5 5 5 5 5 25

Within Columns = 78 - 20.80 - 57.20

Source of Sum of Degrees of Mean Variation Squares ______Freedom Square

Between Columns 20.8 4 5.20 1.82 W ithin Columns 57.2 20 2.8b

Total 78.0 24

From Table V III, page 410, R eference 3, an F o f 1.82 fo r 4 and 20

degrees of freedom is not significant, that is, it was not shown that the

coluan variable caused more variation than that caused by randomness. The division of the total at variance into three parts will account for the variance caused by the row variable and the test becomes significant as

shown below.

The degrees of freedom for:

T o tal sum o f squares = N -l

Between columns sum o f squares a r-1

W ithin groups sum o f squares » N-r 164

N-l » (N-r) + (r-1) where: N ** total number of cases

r * number of columns

If the between rows sum of squares is used, as in the following case, the degrees of freedom are the number of rows minus one.

To divide the total variance into three parts one has to make an additional calculation:

Ro™ ( i y» 2 * iisi! * iaaiS ♦ ♦ L s s i l - (■*sq )2 .5 0 .0 0 S 5 5 5 5 25

R esidual *» 78 - 20.80 - 50.00 « 7.20

Source of Sum of Degrees of Mean Variation Squares Freedom Square *

Between Columns 20.8 4 5.20 11.5b Between Rows 50.0 4 12.50 27.78 R esidual 7 .2 16 0.45

(From Table YIII, p. 410, Ref. 3) Total 78.0 24 1^ level at 4 and 16 df « 4.77 5^ le v e l » 3 .0 1 .

Since the between row and between column differences are signif icant in this case at the 1 per cent level one may say that the differences obtained were actually caused by the various experimental conditions.

Test of Significance (Reference 3). Under the conditions of random sampling from a common normal population, the mean square between groups may be expected to differ only within the lim its of random sampling. The ratio between the two mean squares will give F, the distribution of which was discovered by Fisher and which has been tabulated by Snedecor in the form: F « aean square between groups mean square within groups 185

If the mean square in the numerator is significantly larger than that in the denominator, the hypothesis of random sampling from a common population v ill be rejected* This vould indicate that the means of the groups differ more than can reasonably be expected in random sampling from a common pop ulation . The values of F which constitute the 1 per cent and 5 per cent levels of confidence have been tabulated (Reference 3, page 410); that is, if no real difference existed and a test were performed 100 times, an F value equal to or greater than the stated amounts for the 5 per cent and

1 per cent levels would be expected 5 times and 1 time, respectively* 18b

SUMMARY OF STATISTICAL CALCULATIONS

(Details of Methods, References 3 and 6)

Analysis of Variance

(1) Per Cent Feed Removed .is P ith from th e No. 1 H i l l (T able X)

Source Sum of Degrees of Mean Squares Freedom Square F

Between Groups 692 2 346 6.2

W ithin Groups 1,123 27 41.6

Total 1,815 29

F at the 1 per cent level for 2 and 27 degrees of freedom c 5.57

(2) Total Pith/Feed Ratio (Table XI)

Source Sum of Degrees of Mean Squares Freedom Square F

Between Groups 420 2 210 19.4

Between Rows 592 4 148 13.7

Residual 215 20 10.8

T o tal 1,227 26

For the 1 per cent level for 2 and 20 degrees of freedom - 5.85

For the 1 per cent level for 4 and 20 degrees of freedom « 4.43

(3) P ith from No. 1 M ill/T o ta l P ith Removed from Bagasse (Table X II)

Source Sum of Degrees of Mean Squares Freedom Square F

Between Groups 448 2 224 5.35

Between Rows 1,636 4 409 9.80

Residual 880 21 41.9

Total 2,964 27 187

F, at the 1 per cent level for 2 and 21 degrees of freedom **5.78

F, at the 5 per cent level for 2 and 21 degrees of freedom « 3.47

F, at the 1 per cent level for 4 and 21 degrees of freedom ■ 4.37

(4) Pounds of Pith/Pound of Feed for Various RPM (Table XIII)

Source Sum of Degrees of Mean Squares Freedom Square F

Between Groqps 4,315.8 2 21,570 20,4 (2455, 1135, and 795 RPM)

Within Groups 5,484.0 52 1,055

Total 9,799.8 54

F at the 1 per cent level for 2 and 50 degrees of freedom “ 5.06

CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS

(1) Pounds Pith/Pound Feed vs. Feed tote at 2455 RPM (Table XIII)

Correlation Coefficient =* r a EX E XX - ______N______£ X2 - E Y2 -

X “ Values of feed rate

Y = Corresponding Values of Pounds Pith/Pound Feed

48,088.2 - 49.083.4 262 x 33,802 “ 4

For 16 degrees of freedom an r of .468 is significant at the 5 per cent level. Hence, the correlation is not a significant one. The calculation below is given as a sample. 188

_ v a a r m K m Q o c 2 b - slope of line « ------[■» * - * - 3 . 8 r; y2 _ (£ *) 262 N

Regression Equation:

X is considered as the variable on the horizontal axis, and Y the vertical ax is

Y » -.0038X ♦ a

The constant a is obtained by substituting the average values of X and Y in the equation.

It then becomes:

Y - -.038X + .257

(2) Pounds Pith/Pound Feed vs. Feed Rate at 1135 RPM (Figure 15,

Table XIII) r „ 37A851.1 „.J8 ,610,0 . _#387 '/214 x 17,970 For 17 degrees of freedom an r of .456 is significant at the 5 per cent level, hence this correlation is not a significant one. Even though this is true, this plot is included as Figure 15.

Regression Equation:

Y - -.00461 ♦ .222

(3) Pounds Pith/)Pound Feed vs. Feed Rate at 795 RPM (Figure 16,

Table XIII)

_ 33.508.4 - 34.153.6 r “ ■* ■■■■' « -.5 4 6 *448 x 3^080 For 16 degrees of freedom an r of .458 is significant at the 5 per cent level and one of .590 is significant at the 1 per cent level. Hence, 189

this correlation is significant at the 5 per cent level.

Regression Equation:

Y - .00143X ♦ .158

(4) KVH/Pound of Dry Bagasse Feed vs. Feed Rate at 2455 RPM

(Figure 14t Table XIII)

r - -8,033.8 - 8,456.2 . _#90 ✓247.7 x 902”

For 13 degrees of freedom an r of .641 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level.

Regression Equation:

Y - —000171X ♦ .0065

(5) KVH/Pound of Dry Bagasse Feed vs. Feed Rate at 1135 RPM

(Figure 14, Table XIII)

r c ^775.7^.904.1 . _ #6Q ✓214.7 x 89

For 17 degrees of freedom an r of .575 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level.

Regression Equation:

Y - -.00061 ♦ .00241

(6) KVH/Pound of Dry Bagasse Feed vs. Feed Rate at 795 RPM

2.523.6 - 2.640.9 r - - .90 ✓448 x 38 190

For 16 degrees of freedom an r of *590 is significant at the 1 per cent level* This correlation is significant at the 1 per cent level*

Regression Equation:

Y - -.000026X 4 .00144

(7) Per Cent Ash in Fiber vs. Per Cent Ash in Bagasse for Dry

Operation (Figure 10, Table V)

p , 293.14 - 245.66 „ +#83 vn?:7rx"20i

For 10 degrees of freedom an r of .708 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level*

Regression Equation:

Y » .41X ♦ 1.18

(8) Per Cent Ash in the Fiber vs* Per Cent Ash in the Bagasse for

Wet O peration (F ig u re 11, Table VI)

r . 300.05 - 255.83 „ +#?4 ✓272.95 x 13.03

For 28 degrees of freedom an r of .463 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level.

Regression Equation:

Y » .1621 + 1

(9) Per Cent Ash in the Fiber vs. Pounds of Water per Pound of Ash in the Feed X 10“2 (Figure 12, Table VI). This correlation takes the form of the hyperbola: 191

(Y - 1) (X - 0.5) - 1.2

The values ,, + 1 were calculated. A correlation was then de- X - 0 .5 termined between this calculated value and the measured value of Y. The

correlation coefficient was foimd to be:

r - 13,171 - 10,855 _ #?4 628 x 1,542

For 26 degrees of freedom an r of .478 is significant at the 1 per

cent level.

The regression equation becomes:

^(measured) ***^( calculated) +

Substituting . 1 for *calculated

Y ■ •» [ r r b 4 *] 4 •»

This then is the equation of a line which best fits the data ob tained. Due to the scattering of the points in the plot (Figure 12) the accuracy of the last equation is not warranted. For wet operation, one may say that about 400 pounds of water should be used per pound of ash in the feed to assure that the ash of the fiber will be low.

(10) Per Cent Solids in the Drain Water from the Strainer Tanks vs. Pounds of Water/^ound of Bagasse (Figure 17, Table XIV)

129.994 - 146.746 r ------" ------• ■ -.6 9 y^u.bo x 2.44 192

For 12 degrees of freedom an r of .661 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level.

Regression Equation:

Y - .07X ♦ 1.72

(11) Weight Per Cent Solids in the Drain Water vs. Per Cent Mud by Volume in D rain Water

r . 170.527 - 152.027 „ t>30 ✓173.3 " x

For 12 degrees of freedom an r of .661 is significant at the 1 per cent level. This correlation is significant at the 1 per cent level.

Regression Equation:

Y « 0.107X - .32

t VITA

Robert Marius Hansen was bom in Gulfport, M ississippi, on January

19, 1924. Upon completion of public grade school, he entered Gulf Coast

M ilitary Academy, and was commissioned as a 2nd Lieutenant in the United

States Army immediately following graduation, in June 1942. Two of the

four years that he spent in the service were in the Pacific Theater, where

he served in both the Infantry and Quartermaster Corps.

At the time of separation from the service, in 1946, he worked

briefly for the U. S. Civil Service, then entered Louisiana State Univer

sity, where he graduated with a Bachelor of Science in Chemical Engineering,

in June 1950.

At this time, he accepted a position as Chemical Engineer in the

Tube Development Shop of the Harrison^ New Jersey, RCA Victor plant. Here,

he worked on transistors, colored television, and magnetrons. While at

this position, he attended Newark College of Engineering in the evenings and completed his work for the Master of Science degree in June 1952.

In September of 1952, he received an RCA Fellowship and re-entered

Louisiana State University to work toward a Doctor of Philosophy Degree in Chemical Engineering.

193