Saccharification versus simultaneous saccharification and fermentation of kraft pulp

Enzymes are a significant cost in cellulosic ethanol production, minimizing their use would be desirable as long as ethanol yields and productivities are not reduced. The aim was to evaluate the effects of enzyme dosage on conversion of cellulose to ethanol. Kraft pulp, an intermediate in paper production, was used to represent a fractionated cellulose feedstock. Trials were conducted in a 5 L BioFlow bioreactor (2-3 L working volume) with agitation rate varied (80-900 r/m) to provide acceptable mixing. Based on survey of the literature, an average dosage for cellulase (34 FPU/g glucan) and