Aqueous acidified ionic liquid pretreatment for bioethanol production and concentration of produced ethanol by pervaporation

Acidified [Bmim]Cl solution showed a great efficacy for the pretreatment of softwood, hardwood, rice straw, and sugarcane bagasse. The pretreatment resulted in 29 and 20-fold increase in cellulose digestibility of hardwood and softwood, respectively, and most cellulose in rice straw and sugarcane bagasse was converted into glucose. Fermentation of biomass hydrolysates produced 21.86-29.56 g/L ethanol, thereby achieving ethanol yields of 0.49-0.51 g/g. Ethanol was concentrated up to 79.8% from a fermentation broth containing 2.4% ethanol using four consecutive pervaporations. This work demonstrates the viability of biofuel production from diverse feedstocks and the feasibility of ethanol recovery using pervaporative separation. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.