8-103: Proton beam irradiation pretreatment of biomass and saccharification

Sugar, especially glucose is most important intermediate and building block for conversion to the biofuel and biopolymer and researches to enhance sugar recovery have been conducted through the world. In this study, pretreatment process of rice straw using proton beam irradiation was carried out for the enhancement of enzyme digestibility at different proton beam doses (5 kGy-25 kGy) with 45 MeV beam energy cyclone. The structural change in the surface of rice straw before and after pretreatment was observed by scanning electron microscope (SEM). Surface of pretreated rice straw was visually more rugged than that of control (non-pretreated). Enzyme digestibility was estimated through the analysis of sugar recovery after saccharification of pretreated biomass with cellulase (60 FPU) and β-glucosidase (10 CBU). Optimal dosages of proton beam on rice straw for the recovery of sugar were 15 kGy. When rice straw pretreated at the optimal irradiation condition was saccharified with cellulase and β-glucosidase, sugar recovery was approximately 73 % of theoretical glucose content, which is about 2-3 folds higher than that of control (non-pretreated). Also, a higher initial reaction rate was shown in saccharification when soaking aqueous ammonia (SAA) pretreated rice straw irradiated with proton beam was used.