Effects of Extremely-low-concentration Acid Hydrolysis on Levulinic Acid Production from Rice Husk and Characterization of Cellulosic Structure

The effects of extremely-low-concentration acid hydrolysis on levulinic acid production from rice husk and cellulosic structure were investigated.Using dilute sulfuric acid with mass concentration 0.1% as catalyst,the levulinic acid production from rice husk was studied.The results show that the optimal ratio of liquid to solid is 32∶1(mL∶g),temperature is 240℃,and hydrolysis time is 30min.Under these conditions,12.81% of the total mass conversion yield of cellulose and hemicellulose can be obtained.The cellulosic structure was characterized by methods of scanning electron microscopy,X-rays diffraction and infrared.The results show that through hydrolysis the cellulosic structure was destroyed remarkably.The crystallinity decreased,and cellulose and hemicellulose were also hydrolyzed.On this basis,a comprehensive hydrolysis model of rice husk was proposed finally.