Ionosolv pretreatment of sugarcane bagasse and rice straw assisted by catalytic hydrothermal and microwave heating for biorefining

The pretreatment of sugarcane bagasse (SCB) and rice straw (RS) using ionic liquids (IL) in combination with solid acid catalysts was investigated to enhance enzyme accessibility for biorefining. Both conventional hydrothermal and microwave-assisted treatments were carried out. Optimal conditions were determined in a microwave system using response surface analysis for cellulose digestibility, which was determined by the reducing sugar and glucose yield. The results demonstrate that SCB and RS fractionation in a choline acetate (ChOAc) IL catalyzed by SiO2-OSO3H in the microwave-assisted system and heterojunction metal oxides (SO42-/TiO2/(FeO4)-O-3/WO3) in the hydrothermal system significantly enhanced the cellulose digestibility. The costs of combined pretreatment and saccharification in the present study ranged from 0.60 to 1.48 (sic)/g glucose for RS and 1.26-2.31 (sic)/g glucose for SCB and were comparable to the previous studies. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.