Patent ID: 8980598
Filing Date: 2015-03-17
Classification: C12P,Y02E

Abstract:
1. A dry solids staging fermentation process for producing ethanol comprising: a) an initial fermentation step which includes directly feeding a dry ground cereal grain into a fermentation vessel, combining therein the dry ground cereal grain with one or more starch hydrolyzing enzymes and a fermenting organism at a pH of 3.0 to 6.0, a temperature of 5 to 65° C. for an initial period of 2 to 40 hours, and obtaining a fermentation broth having an initial percent dry solids (% DS) of 15 to 30%; b) a loading step which includes adding a solid fermentable substrate into the fermentation vessel after the initial period of 2 to 40 hours and allowing continued fermentation at a pH of 3.0 to 6.0, at a temperature of 20 to 55° C. for a sufficient period of time to produce ethanol, wherein accumulated % DS of the fermentation broth increases over time and is between 30 to 40%, wherein the accumulated % DS is at least 5% greater than the initial % DS, and wherein the dry solids staging fermentation process is conducted for a total of 24 to 108 hours; and c) recovering the ethanol produced in step b), wherein the yield of ethanol is at least 14% v/v.