Pretreatment Sekam Padi dengan Alkali Peroksida dalam Pembuatan Bioetanol

Rice husk is one of abundant lignocellulosic waste materials in Indonesia, especially during harvesting period. Being abundant and outside the human food chain makes the rice husk is a potential cellulose feedstock for vallue-added applications of bioethanol conversion. Prior the conversion of lignocellulosic material, a pretreatmenet is required to alter the sructures of cellulosic substance accesible to the enzymes that convert the carbohydrate polymers into fermentable sugars. In this experiment the effect of agitation, temperature, and H2O2 concentration to lignin disruption by alkaline peroxide pretreatment at pH 11.5 were studied. It was found that agitation at 150 RPM, where neither vortex nor dead zone was observed, showed the lowest lignin content 10.6%. The higher H2O2 concentration up to 7.5% increased the yield of glucose, but decreased at 10% H2O2. No marked difference in cellulose levels was observed from pretreatment of the rice husks at 25, 35, and 45 oC. During the pretreatment some of the cellulose was transformed into soluble glucose. Hydrolysis and fermentation of the pretreated rice husks produced at least 5% (w ethanol/w husk) bioethanol. Keywords: bioethanol, pretreatment, lignocellulos