Improved pretreatment process using an electron beam for optimization of glucose yield with high selectivity.

In this study, electron beam irradiation (EBI) assisted by a dilute acid pretreatment process was investigated to improve the glucose yield and show high selectivity in the enzymatic hydrolysis of rice straw. In the first step, EBI of rice straw was performed at various doses ranging from 50 to 500 kGy. The electron beam-irradiated rice straw was then autoclaved with 3 % dilute acid at 120 °C for 1 h. The pretreated rice straw was finally subjected to enzymatic hydrolysis at 50 °C for 24, 48, and 72 h by 70 filter paper units (FPU)/mL cellulase and 40 cellobiose units (CbU)/mL glucosidase. Glucose was obtained with a very high selectivity of 92.7 % and a total sugar yield of 80 % from pretreated rice straw after 72 h of enzymatic hydrolysis.