Monday, May 2, 2011
Grand Ballroom C-D, 2nd fl (Sheraton Seattle)
For the bioethanol production using lignocellulosic biomass, the effective pretreatment technology is very important to the extraction of carbohydrate from biomass. Recently various techniques are being developed under condition of acid, alkali, high temperature, and high pressure for the effective pretreatment of biomass. In this study, we newly developed temperature and pressure-controlled expansion reaction system and CO2-mixed physicochemical pretreatment method. This system consists of reactor with high temperature and pressure in upper side, and separator with low temperature and pressure in bottom. To the hydrolysis of biomass, 3MPa of CO2 was loaded into the reactor. After reaction, the sample was spouting into the separator with 6MPa N2 pressure. Rice straw material, milled into 0.3~0.5mm and drying at 45°C for 24 hours was used for pretreatment. At that time, the water content of the sample was 3~4%. Composition analysis of rice straw was performed by NREL protocol and it consisted of 36.3% cellulose, 21.3% hemicellulose, 19.9% lignin, and 11.7% ash. The sample was pretreated with 15% ammonia solution at 150°C for 10 ~ 60 minutes using our new developed pretreatment system. Especially ammonia and CO2 mixed solution were used for pretreatment of rice straw. As a result of pretreatment, the sample was changed to 46% cellulose and 22% hemicellulose with 70% solid remaining. The recovery of cellulose and hemicellulose from this new system was increased by 8% and 22%, respectively, compared with one of control.