Tuesday, May 3, 2011
Rice straw is lignocellulosic biomass, especially agricultural waste that can be converted to bio ethanol. It has become a focus of attention because of their large quantities, low cost, and environmental benefits. The major components of lignocellulosic biomass are hemicellulose, cellulose and lignin. Hemicellulose is primarily a polymer of pentoses and hexoses, Cellulose is a polymer of hexoses. Dilute acid hydrolysis attacks these polymers, especially those from the hemicellulose fraction which is easier to hydrolysis than cellulose. But dilute acid hydrolysis of lignocellulose biomass can be approached as sequential of sugar degradation. Sugar degradation not only reduces the yield of fermentable sugar, but also forms inhibitors to fermentation, such as Fulfural, HMF(hydroxymethylfurfural). Therefore, objective of this study was to determine the effects of H2SO4 concentration and reaction time on the kinetic of sugars (xylose and glucose) and on the reaction inhibitors (byproducts) from rice straw. The Pretreatment and hydrolysis reaction for the rice straw followed a first-order sequential kinetic model. And kinetic model constants can be expressed by Arrhenius equation with the frequency factors for hydrolysis and sugar degradation.