INDUSTRIAL AND ENGINEERING CHEMISTRY
716
Vol. 20, No. 7
Cellulose Resources' 111-Cost
of Field Crops for Cellulose
.
George M Rommel PLEASANTVILLZ, N. Y.
H E R E is gold in sea water, but the cost of getting it out is more than the gold is worth. The gold in the despised cornstalk has tempted chemists and other experimentalists for more than one hundred and fifty years. A German, Jacob Christian Schaeffer, suggested Indian corn as papermaking material in 1765. I n 1802 B. Allison and J. Hawkins took out an American patent for a process of making paper out of corn husks. Twenty years ago the United States Department of Agriculture made an exhaustive study of the corn plant as a source of paper, not stopping with laboratory investigations, but conducting much of their research in actual mill operations. Like the gold in the sea water, nothing came of these efforts because the products cost too much to make or because as good or better things could be produced for the same or less cost from a raw material cheaper than cornstalks. Then came the war, and with it a demand for cellulose from any available source, leaving us a t the close with a new supply of industrial products made of cellulose, new markets opened up with all sorts of attractive things for sale, and soberminded chemists predicting that growing cellulose may be the big development in farming in the next fifty years. Cellulose is the cheapest thing a plant produces, manufacturing it mainly from solar energy by photosynthesis. Trees have their value in great part on account of the cellulose which they contain. They are perennial plants whose volume and weight of cellulose are the result of decades or even centuries of annual accretions. If cellulose can be profitably derived from trees, which require any time up to eighty years before they are ready to harvest, why not get the same material from a plant which can be harvested withinsix months after the seed is sown, especially if the cellulose is found in a by-product of little value obtained in the production of a money crop of much value? Cotton fiber, long used for high-grade paper and explosives, was the first material to be used for making rayon. It has come into such g e a t demand, not only for rayon, but for nitrocellulose lacquers, leather substitutes, surgical dressings, celluloid, pyroxylin, and the like, that cotton linters, once as much of a nuisance to the cotton-oil industry as cornstalks are to the farmer, now have an established place on the market as a standard cotton product. I n the survey which the writer made last winter for the United States Secretary of Agriculture, of research data pertaining to the industrial utilization of farm products, results were compiled from the records of state agricultural experiment stations in the Corn Belt showing grain and forage yields for corn and other crops. Some of these records cover a period of thirty years, while in Illinois they run back more than fifteen years and include crop production on the different soil types found in the state. The yield of cellulosic material which may be expected as a by-product of field production, corn especially, was the subject of the preceding article in this series.* A year ago nothing was accurately known of the probable cost of cornstalks to the manufacturer, nor even to the farmer who grows them.
T
1
Received March 24, 1928.
2
IND. ENQ.CHSM., 20, 687 (1928).
The information now available along these lines will be discussed in this article. Cost of Cornstalks to Manufacturer The apostle of cornstalk utilization in this country is 0. R. Sweeney, head of the Department of Chemical Engineering a t Iowa State College, who, by written and spoken word, has focused attention on the enormous volume of unused cellulose which is produced and wasted every year in the Corn Belt. Professor Sweeney recognized early that the whole problem of cornstalk utilization hinges on the cost of collecting them and getting them to the factory ready for the machines to convert them into something useful. J. B. Davidson and E. V. Collins, of the agricultural engineering section of Iowa State College, undertook to answer this question and were the first men to get accurate engineering data on the cost of collecting cornstalks. During the winter of 1926-27 they experimented with various methods of collecting stalks, and found the most economical outfit to be one of their own contrivance which harvested the stalks from fields where the corn had been husked in the usual manner. It was a combination of a mower, hay-loader, and hay-baler hauled by a tractor which made possible a continuous operation. Details of the costs of collection with this outfit are: Cost of equipment with modifications: Baler or press.. Loader Mower Modification estimate..
.................................... ............................................ ............................................ ............................. Total cost of outfit., ...........................
... ........... ......................... .................................... .................... Total cost per hour.. ........................... Cost per acre ( 2 . 5 acres per hour). .......................
Annual cost, consists of interest, depreciation, and repairs. Assuming 200 hours' use, cost per hour will b e . . Cost of 15-30 tractor per hour.. Foreman, per hour. Three men at 50 cents per hour each..
Assuming a yield of 0 . 8 ton per acre, moisture-free, the cost Der ton will be as follows: Harvesting Baling wire.. Harvested stalks at farm..
........................................ ...................................... ..........................
8565.00 135.00 86.00 114.00
900.00 200.00 1 .OO 1.50 1.25 1.50
5.25 2.10 2.62 0.50 3.12
To these costs should be added an allowance for transportation, for feed and fertilizer removed from the farm, and for the farmer's profit. An average haul of 8 miles was estimated and the cost of transportation distributed as follows:
.................................... $0.30 1.40 .................. Total for transportation.. ....................... 1.70
First ton-mile.. Additional ton-miles, 7 at 20 cents..
All these costs were figured on a very conservative basis. Charges for farm labor are high and considerable labor could be saved, as by use of an automatic bale tie, two men being needed to tie bales with this outfit. The transportation charges are higher than the average in the Upper Mississippi Valley. The Bureau of Public Roads estimates that the cost of trucking in this section will average 8.5 cents per ton-mile for all kinds of roads. The charge a t this rate for 8 miles would be 68 cents per ton as against $1.70 in the Iowa figures. A factory buying cornstalks from farmers and doing the hauling would have to add something to this figure for loading and unloading.
The Uaridron-Crillins figures were oi;en to bill oiio frizwuod Pmdueis Corpuiniioo, Dubuque, lowe. B company proporing to eastern corn-growing states is to cut and shock corn and manufacture wdltonrd out of cornstalks. Cost data of ihisopciation were husk out of the shock. This practice has never been exnot aiailabie at time of writing. tensive in Illinois or Iowa on account of the labor required. possible by the extensive operations of the Cornstalk I+odiicts Davidson arid Collins give the rate in Iowa for shocking Company in Vermilion County, Ill. This company secured corn, twelve hills square, as 12 to 15 cents per shock, or the services of Harvey J. Sconce, who has a wide reputation $2.96 at 12 cents a shock and $3.70 at 1 5 cents. A mechanas a successful farmer, corn grower, and business man, to ic;d s1iot:ke~has been suggested BS an attachment to the head their raw-material product.ion department. Sconce laid the plans for his cornstalk-harvesting as thoroughly as if lie mere embarking on an elaborate corn-breeding investigation. He himself used, or gave farmers the opporturiiiy to use, every conceivable method of collecting cornstalks. Stalks were cut with monTers, raked up with l ~ u l lrakes, and hauled to balers at one side of the field and bnled as they came in. They were cut with corn harvesters and the bundles hauled t.o the baler. After the ground froze, stalks were broken off by hauling a piece of railroad iron over the field, then raking them up with a bull rake. In all these methods the ears had already been picked, and the stalks were balcd without shredding. The most impressive method was that in which grainharvesting and conistalk-collecting were combined. The standing st,alks were cut in the field with corn harvest,ers and Cornstalk PfOdUEt* COmOBny’8 Oprstionsin the bundles hauled to the farmer’s crib. There they were Harvesting Scene in 1927 in vermilion county, III. run through a husker-shredder, which delivered the ears to The husker-shredder is behind the loaded wagon. The farmer’s wagon the left is reeeivlng the ears from t h e husker-shredder and the elevator the farmer’s wagon, whence a portable elevator conveyed them at from the w w o n t o t h e crib Shows plainly., At th? risht is the baler and of hales ready for loading. The bairi (8 en ordinary hay baler. It i s to tlie crib, while the shredded stover was delivered to a hay piles the “bottle neck,’’ and t h e ODeratcon can move no laster than the baler _I/ haler a t the rear of the machine. By this method the farmer turn out the hales of shredded stover. got his corn husked for the stover and the company got the cornstalks for the cost of harvesting the corn, husking, shred- corn harvester. I n case it is feasible from an engineering ding, baling, and hauling the bales to the factory. The com- standpoint, the cost of hand shocking may he set as a pany riser1 all available forms of field power-horses, miiles, figure against which an operator may calculate the econm d tractors. I n all, 10,000tons of cornstalks were baled and omy of machine shoeking. The saving in gross weight of haded to the factory at Tilton. stover, tho probable improvement in quality of grain, and the The corn-harvesting season of 1927 was one of the most avoidance of serious weather obstacles should also be est.idifficult for t,he purpose of such a determination that coiild be mated as credit items against the additional expense of this imagined. The crop was light and during October heavy method of collecting cornstalks. storms had blown t,he corn down so that a considerable amount of it was flat on the ground, making it exceedingly Cost of Other Field-Crop By-Products to the Manufacturer diEcult to gather. Storms also occurred late in November, The story of the cost of straw for rrranufacture is short which made it impossible to get into the fields for nearly a month. In spite of these obstacles the company found that, :%lidsimple. The business is largely in the hands of local with ai1 average haul of 15 miles, the cost of baled stalks owners of baling-pre s, who travel around t.he country delivered to the factory was less than 88 per ton, iiicludirig buyirig str:m in the stack from farmers and then selling it to farmtm’ compensat,ion. St,alks were hauled from fields 20 1he mnnuftlcturers. The price which farmers get varies from miles from lhe plant for as little as $5.70 per ton. The com- 75 cents it ton in t,hc stack to $1.60 a ton. I3nling costs are pany believes that, in a normal year the average cost shoiild quite uniform. In most sections of the Middle West b a h g not exceed 86.00 and t.hat it might he as low as $5.00 per ton costs $3 per ton. Beyond the Missouri River the charge is delivered a t the factory ivithout reducing what farmers get somet,imes as low as $2. The straw costs the manufacturer out of it. It should be noted that Vermilion County is from $7.50 to $14 or even $15, by the time it is delivered blessed with good roads, which reduce the hauling chitrges t,o him. The Straw- Products Company, of St. Paul Park, Minn., at last reports was paying $9 a ton for straw delivered to a minimum. The uncertainty of weather conditions diiring the m o n t h t,o the plant. The buying methods of the Celotex Company are compliin which corn is harvested is a factor of importance. The season of 1927 was except.iona1 in many ways and may not cated, but work out a t about 25 cents for each ton of sugar soon be repeated, but it is desirable to rondcr operations cane. As the cane yields ahout 500 pounds of wet bagasse of this kind independent of the weather as far as possible. to the ton, this makes the bagasse cost the Celotex Company It would therefore seem to be in line with good farming prac- $1 a ton before it handles it. It is reported that the company tice and economy to the company utilizing cornstalks for the plans to ptiy somewhat more for bagasse from the P. 0. J. corn to be harvested as soon as ripe and shocked in the field. canes on account of their greater fiber content. The comThe corn could then be hauled from the field to the husker- pany has found it necessary to install baling plants a t the
ISUCSTMINA L A S D ENQIJIN&&IZINGCHF.VISTRY
718
Vol. 20, No. 7
According to Hawloy and Wise,3 analyses of certain woads made at the Forest Products Laboratory run all the way (rum 41.60 per cent cellulose in incense cedar to 61.85 per cent in white spruce. Cellulose Content of Cornstalks and Other Annuals If a plant contains a certain amount of cellulose, what will be its yield in manufacturing? The Cornstalk Products As most of the available analyses of farm produets have Company states that i t finds cornstalks to contain from 35 to been made from the standpuimt !if their feeding d o e , their 40 per cent "extractable cellulose." This company also celliilose content is not accurately knoini. The feeder cun- claims that. 4 tons of its cornstalk pulp will make 3 tons of sults his feeding tables, looks far protein and then for muck alpha gulp. Tlie liational Bureau of Standards analyzed fiber, and with this information determines the value of samples of alpha pulp furnished by the Cornstalk Products any f e d that he may be about tu use, the aniount of crude Company and reported an aT.erage content of 95.6 per cent fiber being a rough index of digestibility. The mannfao- of alpha cellulose. The company informs the writer t,hat this turer will place greatest importance on the cellulose c.rint,ent, pulpwasmadeinasmall mill. n-hich in a way is indicated by t,he amount of the crude fiber; There is need for a method of determining cellulose so what the manufncturw isants the fccrlcr mnnot iiw. that, by knowing certain facts, the cellulose content of a plant can be determined for practical purposes. At present there is no fundamental basis for comparison. This is not by any nieans a simple problem, as can be seen by only a cursory exiLmiiiat,ion of the literature of cellulose chemistry. Easy prohienis in chemistry, as in other branches of knowledge, are not left as the last to be taken up. sugar mills whose bagasse it buys, and tlie ezprnse of getting the product to the factory is nut inconsklerable. Tlie company hns never given out these figures.
Cost of Cornstalks to t h e Farmer
Baled CornsfaIra Arriving at the Factory *f Tllfon. 111. Concrete r a d s in Vermilion County hiid m u c h to do with keeping dawn delivered C O B ~ Dof baled coresfdks.
The standard referenee book and the chief source of informat,ion on the analyses of common farm products is Henry and Morrison's "Feeds and Feeding," which contains summaries of analyses of feedstuffs made at American agricultural experiment stations. The yield of cellulose in cornstalks and straw will be indicated from the data in the HenryMorrison tables for crude fiber. The proportion classified as "nitrogen-free extract:' is usually obtained by difference and contains some cellulose. It is believed that,, if 5 per cent is added to the figures for crude fiber in t,he following brief tabulation, the result will be fairly close to the actual content of cellulose. Anslyees of Certain Cereal By-Product8 (From Henry and Morrison's "Peed and Feeding") C*R?3"*W"R*isS CRUnB N~P.KE corn IesYeS 13.4 Corn husks 24.7 corn tops 17.9 Corn stalks 17.7 Corn stover (err removed). very rir" -,
9 d
corn slaver medium in water 19.o Corn stover high in r a t e r 41 0 nariey d r a w
oat stiaar
Rice strsw
s4.2 11.5
7.5 71 8.4
Rye straw Whrnt sirhw Buckwheat stia% 9 . 9
ASA
PROTSIN
7% 6.2
% 7,1
2.5 5.6 5.2
5.6 4.8
2.9
Pisen zxra*cr P A T % % % 22.1 39.4 1.8 24.9
27.4 27.8
44.2 42.0
0.8
43.1
1.5 1.4
5.8
3.9
30.7
46.6
1.6
5.5
5.7
27.7
40.9
1.2
3.8
3.9
20,l
30.2 38.1 40.8 39.2
1 0 S.5 Y 4 1 4
247 117 41 13
1 5
27 3
5.7 5.4 14.5 3.2 5.2 5.5
3.6
3.0 3 ~ 9 3.0 3.1 5.2
36.0 36.2
33.5
g8.s
67.4 43.0
46.6 44.4
35.1
1.2
1.3
183
97
7
It is obvious that tlie manufact,urer who lins his eye on cornstalks will need more accurate information on the cellulose content of cereal by-products t.han these figures give.
The actual worth of cornstalks to a farmer cannot be satisfactorily determined on the basis of any research data known to tho writer. This problem will probably be worked out by the trial-and-error method before it will be solved by research methods. It is a common practice in the central part of the Corn Belt to rent cornstalk fields for pasture for $1 an acre after the corn is harvested, the farmer thus also getting the benefit of manure dropped on the field. If the cornstalk yield were 1 to 2 tons per acre, custom would thus assign a feed value of 50 cents to $1 a ton plus such additional value as might be placed on the mannre--say, a total value, including both feed-rent and manure credit, of 75 cents to $1.25 a t.on. The proportion of t.he corn crop in the entire country which goes into the silo is less than 5 per cent, and that which is grazed by animals (hogged off) and grown for forage is 11.45 per cent; the remaining 84.35 per cent is harvested for grain. I n the nine leading Corn Belt states only 2.35 per cent of the crop is put in the silo, 11.83 per cent is grazed or grown for forage, and 85.85 per cent is harvested for grain. No fault can be found academically with the logic of the farmer who firmly takes the stand that he will permit no roughage to leave his farni except "on four legs" but, speaking practically, the country could not absorb all the meat and dairy products that could be made if all the c o r n s t a h and straw produced in the Corn Belt were fed to livestock. As we have seen, the leaves and husks contain most of the feed value in cornstalks, and it seems that practical methods of taking t,hem off the stalk can be devised, in which ease they would have a value about equal to that of timothy hay. Cornstalks (stems) can be put into condition for animals to eat by cutting and putting them into the silo, or by shredding, but thepe are expensive, laborious processes. The stem oE the corn plant has fulfilled its purpuse the moment the ears are husked. The information on the fertility value of cornstalks is still less satisfactory than that on its feed value. All the statemenbs on this point have been based on straight chemical analyses of nitrogen, phosphorus, and potassium present. Values of these elements as indicated by local cost of fertilizers a t the time the analyses were made were taken to estimate the money value of the fertilizing constituents removed from the soil in a ton or an acre of cornstalks. No I"%'he
Chemistry of Wood,.' The Chemical Catales Co.. Inc., 1920.
July, 1928
INDUSTRIAL A N D E.VGINEBEING ClIEZlISTEY
attention was paid to the availability of the fertilizing constituents, and this discrepancy throws the assumed values out of line, especially in t.he case of nitrogen. It is now known that the microorganisms which decompose cellulose do not act in the absence of nitrogen. Therefore, cornstallcs will decompose only if nitrogen is added t o them, or if they are plowed under, at the expense of nitrogen already in the soil. It appears that much research and considerable practical experience will be needed before this question can be given an intelligent answer. I t is obviously ridiculous t o argue about the fertility value of cornstalks with a man who rakes them up and burns them every spring, or for such a man to contend thxt they m e worth 83 or $5 or some other figure a ton when he would h i m them tip anyway. Likewise are both sides to the debate off the track when the corn borer is rieht around the cnrnev
Tlie runiance of cellulose is one of the most fascinating &\&pments of tire post.-war period, but the things that have comnsred to what mav be done when heen done :%reas nothing~. the full inianufirctiiring possibilities of this now litt,le used material we developed. Cellulose abounds wherever soil and moisture encourage plant growth. Its very ahundnnm staggers t.he imagination. The United States produced nearly 80,000,000 pounds of rayon last year-a tremendous amount-but tlie cellulose needed for it could hai-e been produced in any one good Illinois or Iowa corn county out of cornstalks without the least, strain. Even paper, wliich tlie average man thinks of as a great national problem so far as the sollrco of its Ekw inaterial is concerned, is "small st,iiff" when we balance its requirements against the total output of our forests. If rre had to, and if it paid to do so, tlie cornstalks which now rot or are burned up every year in the nine states which we have been considering could be used to furnish the pulp to make all the paper the country now uscs. Celotex, which flashed its way across the horizon to t,he consternation of the lumber industry, will probably use not inuch more than half of the 375,000 tons of dry substance in the sugar-cane bagasse which will be produced in 1,ouisi:zna this year. According to the Department of Agriculture, Illinois averages 9 million acres of corn each year, of which 89 per cent is harvested for grain. I n Iowa the average annual acreage is 11 millions of which 83 per cent is harvested for grain. So in Illinois and Iowa togetlier the cornstalks from 17 million acres are available to the manufacturer. If we take the figure of 2750 pounds of stover per acre as the probable average annual yield on farms,* we hizve a total production of corn stover of 23,375,000 tons. If we deduct 50 per cent for the weight of the leaves and husks, we still have ll,F87,000 tom of bare cornstalks. If we allow onethird for moisture content, we have, in round numbers, 8 million tons of bone-dry material that farmers can't use for feed because aninials won't eat it-too much cellulose in it. That is enough raw mat.eria1 in these two states alone for forty-two iimes the quantity of insulating board that the Celotex Company makes in a year!
719
What is iieedod to make cornstalk utilization a source of revenue generally to Corn Belt farmers is a demand for manufacture that calls for tonnage and lots of it. And that will necessitat,e chemical research beyond anything that has yet been attempted. What is cellulose good for that human beings elin use, except to make paper and sausage casings, rayon and celluloid, lacquers, explosives and so on? The chemist must answer that question; the miter is not a clieinist and pleads his ignorance as his excuse for passing the buck. A Boston contractor is said to be using a cellulose compound for flooring, and be claims that he has made a number of installations in schools and factories in the vicinity of Boston, with good results. This suggests still XTider applicabions, because it, is only a step from flooring to other structiml uses.
Coiirlrsy Carnsloik Products Conipnny
Stacks of Baled Cornstalks st the Factory of the Ccrrmfa?k Products Company, Tilfon, 111.
It rvould seem worth while to investigate the possibilities of putting cornstalks or wood u m t e through o m or more
stages of the phenolaldehyde process. S j d i e t i o lumber might, he produced which woidd have all the advantages of the natural product and none of it.s disadvantages. It might be possible to go even further and produce by this nieans soruething that would be entirely outside the category of lumber uses. It is a job for the chemist, and it is not confined to tlie utilization of any one product; it is "the new cornpetition" vrit,lia vengeance. Pure resewcii is needed to develop more accurate and campreliensive knowledge of the characteristics and properties of the cellulose molecule. Given that information, the inan would be foolish who would dare predict t.he additions t,o our wealth and comfort whicli may follow the utilization of our cellulose resources.
Synthetic Nitrogen Threatens Chilean Nitrate Fixation of atmospheric nitrogen has reached a point which thieatcns the dominance of Chile's nitrate deposits in the world's fcrtilizcr markcts, and may oblige the Chilean producers to adjust their plans of productioii and sales to conform with the competitive sittiation thus brought about. These views were expressed by F. G. Cottrell. chief of the fertilizer and fixed nitrogen investigation work of the United States Department of Agriculture, in ail address delivered June 14 before the National Fertilizer Association at Old Point Comfort, Va. It i s not yet fully appreciated, even by people closely associated with the fined nitrogen industry, said Doctor Cottrell, how fundamental and revolutionary are the changes it has introduced. Chilean nitrate deposits have determined world prices in nitrogen products for nearly a century. because until recently they were the only independent and practically unlimited sources of such compounds Today the fixed-nitrogen industry has overcome difficulties limiting its production to such a degree that the Chilean monopoly is no longer in complete control of world nitrogen prices. Hereafter, Doctor Cottrell said. Chileail nitrate production will have to follow and adjust itself t o world price levels established by costs in synthetic nitrogen production.
