Patent ID: 9453249
Filing Date: 2016-09-27
CPC Classification: C08B,C08H,C12P,C13K,F23G

Claim Text:
1. A process for producing hemicellulose sugars from cellulosic biomass, said process comprising: (a) extracting hemicelluloses from cellulosic biomass by a batch or continuous extraction reactor in the presence of steam, to produce a cellulose-rich solids stream and a liquid extract comprising water, wherein hemicelluloses and acetyl groups are released from said cellulosic biomass, and wherein said liquid extract contains at least 5 wt % solids; (b) hydrolyzing said liquid extract in the presence of sulfuric acid, heat, or enzymes, to produce a hydrolyzate comprising hemicellulose sugars and additional acetyl groups released during said hydrolyzing said liquid extract; (c) introducing said hydrolyzate to an evaporation stage, to produce a concentrated extract, wherein said evaporation stage is operated at a pH of 4.8 or less, wherein acetic acid obtained from said acetyl groups released from said cellulosic biomass and said additional acetyl groups released during said hydrolyzing said liquid extract, is evaporated from said evaporation stage, and wherein said concentrated extract comprises said hemicellulose sugars; and (d) recovering or further processing said hemicellulose sugars.