Effects of acidified aqueous glycerol and glycerol carbonate pretreatment of rice husk on the enzymatic digestibility, structural characteristics, and bioethanol production

Rice husk as an abundant biomass was used in this study, and it contained 30.1% glucan and 13.5% xylan, 22.4% lignin. The pretreated rice husk with glycerol carbonate and acidified aqueous glycerol (10% water) at 90 °C and 130 °C for 60 min had the maximum yield of glucan digestibility which was 78.2% and 69.7% respectively, using cellulase for 72 h. The simultaneous saccharification and fermentation was conducted anaerobically at 37 °C with Saccharomyces cerevisiae, 5% w/v glucan and 10 FPU/g glucan of cellulase. 11.58 and 8.84 g/L was the highest ethanol concentration after 3 days of incubation form pretreated rice husk with glycerol carbonate and acidified aqueous glycerol respectively.