Process for improving the hydrolysis of cellulose in high consistency systems using one or more unmixed and mixed hydrolysis reactors

摘要

Provided is a process for the enzymatic hydrolysis of cellulose to produce glucose from a pretreated cellulosic feedstock. The process comprises providing an aqueous slurry of the pretreated cellulosic feedstock that has a water content that is less than about 140% of the maximum water holding capacity of the pretreated cellulosic feedstock. The aqueous slurry of the pretreated cellulosic feedstock is fed to one or more unmixed hydrolysis reactors and hydrolyzed with cellulase enzymes therein. In the unmixed hydrolysis reactor(s), the cellulase enzymes hydrolyze a portion of the cellulose to produce soluble sugars, thereby producing a mixture of partially hydrolyzed cellulose containing soluble sugars. The hydrolysis of the cellulose to glucose is continued by feeding the mixture of partially hydrolyzed cellulose to one or more mixed hydrolysis reactors. Also provided are systems for carrying out the foregoing enzymatic hydrolysis.