Study on the process of simultaneous saccharification and fermentation for wet exploded rice straw to bioethanol

Lignocellulosic biomass is the world´s most abundant renewable resource. Conversion of lignocellulosic biomass to biofuel, such as bioethanol or biobutanol is viable because of its broad availability. There are about 1800million metric tons rice straw in China. The rice straw can be converted to bioenergy through bioprocess. The effects of the conditions of wet explosion, the amount of cellulase, β-glucosidase, xylanase and the preenzymatic hydrolysis time on the simultaneous saccharification and fermemtation (SSF) were studied. The results showed that (1)the wet explosion for the rice straw under different conditions had obvious effects (2)the pretreated feedstock at the preteated temperature 160°C, the inlet pressure 4atm O₂, the alkalic amount 6%(w/w), the reaction time 20min can promote the saccharification and fermentation effectiveness(3) the optimal conditions were obtained through SSF process with the cellulase 20FPU/g cellulose, β -glucosidase 40U/g cellulose, xylanase 800U/g at 45°C for the pre-enzmatic hydrolyzed time 8h and 72h SSF hydrolysis. The best converted yield of ethanol was up to 85%, comparable to the dry mass of cellulose. The wet explosion process and SSF technology have board prospect for bioengergy-the second generation bioethanol.