Patent ID: 7998713

Claim:
A method for producing ethanol comprising: a) for a period of time up to about 25 hours, contacting biomass with an aqueous solution comprising ammonia, wherein the ammonia is present at a concentration at least sufficient to maintain alkaline pH of the biomass-aqueous ammonia mixture but wherein said ammonia is present at 12 weight percent or less relative to dry weight of biomass, and further wherein the dry weight of biomass is at a solids concentration of at 15 weight percent or more relative to the weight of the biomass-aqueous ammonia mixture; b) contacting the product of step (a) with a saccharification enzyme consortium comprising one or more hemicellulose-hydrolyzing glycosidase, under suitable conditions to produce fermentable sugars wherein said fermentable sugars provide a carbohydrate source for a biocatalyst for a fermentation process; and c) contacting the product of step (b) under suitable fermentation conditions with a suitable biocatalyst to produce ethanol.