Evaluation of a dry corn fractionation process for ethanol production with different hybrids

Abstract

The effect of a specific dry fractionation process (FWS fractionation process) was evaluated on final ethanol and glucose concentration of 11 yellow dent corn hybrids in this dry grind corn process. In dry fractionation a dry de-germ de-bran process (similar to conventional corn dry milling) is used to separate germ and pericarp (bran) fiber prior to fermentation of the endosperm (grit) fraction. Fermentation results of grits produced from the FWS process were similar to whole corn samples and better than previously reported results on fermentation of grits from other dry fractionation processes. Further investigation showed that the amount of fat in FWS fractionated grits were 2–5 times more than grit samples from a commercial corn dry milling plant; suggesting reduced germ separation with more than 50% of germ not recovered and lost with the grits fraction. Final ethanol concentration for different corn hybrids varied from 12.7 to 13.8% (v/v) for whole corn and 13.4 to 14.7% (v/v) for grits samples. Dry fractionation (removal germ and bran) prior to dry grind processing, significantly affects the fermentation characteristics of corn hybrids. Corn dry fractionation can increase final ethanol concentration and recover germ and fiber as valuable coproducts.