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Volume 6
N u m b e r 10
M A Y 20, 1928
Cellulose from Cornstalks At Tilton, a suburb of Danville, III., there has been put into operation the one-ton pilot plant of the Cornstalk Products Co., Inc., a subsidiary of the Euromerican Cellulose Products Corp. T h e site was chosen because of the great acreage devoted t o corn-growing within a radius of twenty-five miles and t h e availability of a n idle factory. T h e buildings are being equipped with standard machinery a n d apparatus, a n d during the past fall and winter some 10,000 tons of baled cornstalks were de livered t o the company. T h e s e stalks as delivered cost from $5.68 t o $10.00 a ton with a n average under $9.00, made high by the pioneer character of t h e work and the late season in which part of t h e stock was accumulated. Although complete analyses have n o t been published, t h e cellulose appears to have suffered no deterioration in t h e huge piles of bales since collection.
first wash waters. These pentosans are of interest t o the lac quer industry where they may compete with ester gums. The process is shown by the flow sheet. The baled stalks are fed to a cutter and the cut material blown to a cyclone, where some dust is separated. A rotary washer next removes the re maining dust and some cold water-soluble material, a total of
Courtesy of Cornstalk Products Co. C o r n s t a l k s at t h e T i l t o n Factory
Courtesy of Cornstalk Products Co. P a r t of Factory and R a w M a t e r i a l S u p p l y
5 per cent of the weight of the stalks. This water is circulated and may be evaporated to recover these by-products. The fiber then passes to a Jeffry mill or shredder, where it is further reduced. N e x t it is given a hot-water leaching, the water being recirculated t o build up the content of carbohydrates, etc., to commercial concentration. The fiber, after dewatering, is weighed and put in a vertical digester with 9 per cent of its weight of caustic and is cooked
The company proposes t o m a k e cellulose for the chemical and paper industries and t o sell or work u p all by-products. The latter consist of water-soluble materials, such as ferment able carbohydrates, which are t o be sold as such and which are found in t h e wash water. T h i s water is to be recirculated until t h e content reaches a marketable percentage. I t may p a y to evaporate this solution. Additional water-soluble compounds come o u t in t h e hot-water leaching. The caustic-soluble pen tosans, etc., are to be recovered from the digester liquors and
Courtesy of Cornstalk Products Co. P a p e r M a c h i n e and Pulp Drier
Courtesy of Cornstalk Products Co. S e c t i o n of P i l o t Mill
under 20 pounds pressure for 4 hours. The digester content is 8 to 10 per cent pulp. I t is then blown off, filtered, and washed. From the digester liquor and the first wash water, pentosans and a complex mixture of compounds may be recovered. T h e caustic is also subject t o recovery. T h e digested fiber is now given a light beater treatment, is screened twice to eliminate oversize fibers, and dewatered on an Oliver filter before bleaching. On the basis of air-dry cornstocks 1 per cent of bleach is used, or 3 per cent on the air-dry pulp basis. Bleaching powder will be used at first and chlorine
9
INDUSTRIAL AND ENGINEERING CHEMISTRY FLOW SHEET OF THE DORNER PROCESS I BALED CORNSTALKS
cutter
cutter
The company bases its hopes for success upon the quality of cellulose it expects to produce, t h e value of the by-product carbohydrates a n d pentosans, and the comparison between its calculations of costs a n d costs in the soda-pulp industry. In published reports of t h e company these comparisons are given as follows., based on producing 100 tons p e r day, of 75 per cent alpha-cellulose:
[ROTARY W A S H E R L '
(FIBER I U**J
[ôoscutter
Γ — '
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| R E C | f f j S k A T i < H [ÔITVER FILTER FILTRATE HOT-WATER SOLUBLES SOUP W H E N {CONCENTRATED
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FIBER) WEIGHING TANK
DIGESTER
BLOW-OFF TANK OUIVER W A S H E R AMD DEWATENER pIGESTEe 1 FIBER | LIQUOR 1 BEATEff] WASH ITANKl WATER BY-PRODUCT)
cutter [PULSATING SCREENl
BLEACH LIQUOR TANKS
pDLlVER P g W A T E R e V l I PULP | | WHITE WATER| |BROWN PULP BIN (
BLEACHING LIQUOR
~jBLEACHING |OLIV
