Patent ID: 8709770
Filing Date: 2014-04-29
Classification: C12M,C12P,Y02E

Abstract:
1. A process for the enzymatic hydrolysis of cellulose to produce glucose from a pretreated cellulosic feedstock, the process comprising: (i) providing an aqueous slurry of the pretreated cellulosic feedstock, which aqueous slurry has an undissolved solids content of between about 12 wt % to about 40 wt %; (ii) introducing the aqueous slurry of the pretreated cellulosic feedstock to an unmixed hydrolysis reactor; (iii) adding cellulase enzymes to the unmixed hydrolysis reactor before the step of introducing (step ii), during the step of introducing (step ii), or a combination thereof, wherein in the unmixed hydrolysis reactor, the cellulase enzymes hydrolyze a portion of the cellulose to produce soluble sugars and reduce the viscosity of the aqueous slurry, thereby producing a mixture of partially hydrolyzed cellulose containing soluble sugars; (iv) continuing the hydrolysis of the cellulose to glucose by feeding the mixture of partially hydrolyzed cellulose containing soluble sugars to a mixed hydrolysis reactor that effects mixing of the mixture or a hydrolysis system comprising mixed hydrolysis reactors that effects mixing of the mixture; and (v) withdrawing a stream comprising glucose and unreacted cellulose from the mixed hydrolysis reactor or the hydrolysis system of step (iv), wherein the power consumption associated with said process is reduced relative to an otherwise identical process employing a mixed hydrolysis reactor in step (iii).