A novel mixing strategy for maximizing yields of glucose and reducing sugar in enzymatic hydrolysis of cellulose

This work explores the effects of mixing on enzymatic hydrolysis of cellulose to innovate a novel mixing strategy that maximizes glucose and reducing sugar yields for production of cellulosic ethanol while reducing the power required for reactor mixing. Batch experiments of cellulose hydrolysis are performed under aseptic conditions for 72 h at various substrate loading (2-6% wt./vol.), where the reactor mixing is terminated after different intervals of time ranging from 0 to 72 h. We find that initial mixing for a certain 'optimal mixing time' followed by no mixing for the rest of the reaction time maximizes glucose and reducing sugar yields. We report a maximum of 26% and 31% increase in glucose and reducing yields, respectively, in case of optimal mixing over continuous mixing for 2% substrate loading. We obtain an algebraic expression that predicts that the optimal mixing time increases exponentially with substrate loading. (C) 2013 Elsevier Ltd. All rights reserved.