Comparative Studies on Effect of Pretreatment of Rice Husk for Enzymatic Digestibility and Bioethanol Production

Three different pretreatment methods for the rice husk were investigated. in order to determine how each method is affected on the composition of the rice husk, the digestibility of the rice husk in enzymatic hydrolysis and the ethanol production, dilute-h2so4 (1%v/v, 121°c, 30 min), dilute-naoh (3% w/v, 121°c, 30 min) and heat treatment (121°c, 30 min) were employed. among them, the best result was obtained when the pretreatment of rice husk was carried out with 3% of naoh solution. the pretreatment of rice husk with naoh substantially increased the lignin removal, enzymatic digestibility of cellulose, the accessibility of cellulose and fermentable sugar production. the highest glucose concentration, glucose yield and ethanol concentration were 14.54 g/l, 59.6% and 6.22 g/l; which were 5.44, 3.77 and 6.15 times higher than the untreated control samples, respectively. moreover, the sem analysis of the pretreated sample illustrated significant physical changes of the rice husk after naoh pretreatment.