ARS | Publication request: CORN MILLING PRETREATMENT WITH ANHYDROUS AMMONIA

Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2002
Publication Date: January 1, 2003

Interpretive Summary: To improve the security of liquid fuel supplies, while creating jobs and businesses in rural areas, the government provides a tax incentive, promoting the use of ethanol in gasoline. Ethanol is produced from corn in fermentors, where yeast cells consume the glucose sugar that comes from the starch in the corn. However, ethanol produced this way is too expensive to compete directly with gasoline. In this paper, it is proposed that the cos of producing fuel ethanol can be reduced by treating the corn kernels with anhydrous ammonia. By loosening the outer covering (hull) of the corn kernel, this treatment makes it easier to separate and recover valuable co- products, the sale of which will reduce the net cost of corn. Because the cost of corn is the highest cost in the production of fuel ethanol, lowering the net cost of corn will significantly reduce the overall cost of producing ethanol. Application of this technology will benefit ethanol producers, corn growers, transportation fuel consumers and taxpayers.

Technical Abstract: Exposure to anhydrous ammonia is suggested as a pretreatment for corn milling. Batches of corn were exposed to ammonia under controlled conditions. The amounts of ammonia absorbed and reacted with the corn were measured. The amounts were not more than are needed as nutritional supplement for yeast fermentation to ethanol. Loosening of the hull was observed qualitatively, and subsequent shearing in a disk mill followed by steeping for 2, 4, 6 or 8 hours showed that germ could be recovered at higher yield and after a shorter steeping time compared to untreated control batches. Quality of oil was not affected by treatment with ammonia.