Grain milling process

Abstract

A modification is described of a dry grind process for producing ethanol and other co-products from whole grain, whereby the mash is thermochemically treated by cooking the mash in the presence of an organic acid. The organic acid effectively hydrolyzes both the starch and hemicellulosic components in the milled corn to provide fermentable sugars from both the endosperm and other parts of the kernel, without, however, also producing fermentation-inhibiting levels of other known products of the acid hydrolysis of hemicellulosic materials, such as hydroxymethylfurfural (HMF) and furfural. Further, the organic acid is able to solubilize both the starch and the more recalcitrant hemicelluloses while only partially hydrolyzing the same, so that most of the starch and hemicelluloses are hydrolyzed to oligomers and the amount of chemically labile and reducing sugars is kept sufficiently low as to also not appreciably interfere with the fermentation to ethanol.