Organosolvent pretreatment and enzymatic hydrolysis of rice straw for the production of bioethanol

Abstract

The present study investigates the operational conditions for organosolvent pretreatment and hydrolysis of rice straw. Among the different organic acids and organic solvents tested, acetone was found to be most effective based on the fermentable sugar yield. Optimization of process parameters for acetone pretreatment were carried out. The structural changes before and after pretreatment were investigated by scanning electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR) analysis. The X-ray diffraction profile showed that the degree of crystallinity was higher for acetone pretreated biomass than that of the native. FTIR spectrum also exhibited significant difference between the native and pretreated samples. Under optimum pretreatment conditions 0.458 g of reducing sugar was produced per gram of pretreated biomass with a fermentation efficiency of 39%. Optimization of process parameters for hydrolysis such as biomass loading, enzyme loading, surfactant concentration and incubation time was done using Box-Benhken design. The results indicate that acetone pretreated rice straw can be used as a good feed stock for bioethanol production.

Development of a novel sequential pretreatment strategy for the production of bioethanol from sugarcane trash

“…The decrease in reducing sugar yield with increase of biomass loading may be due to poor penetration of the pretreatment agent at high biomass loading. Similar observation was earlier reported bySindhu et al, 2012 for organosolvent pretreatment of rice straw.…”

Fractionation of Hemicelluloses and Lignin from Rice Straw by Combining Autohydrolysis and Optimised Mild Organosolv Delignification

“…The delignification time was not an important factor if only partial lignin extraction was the objective, but a minimum ethanol concentration was important as shown by experiments 11 and 12 where the delignification yields were lower (19.7 and 10.8%). The delignification yield obtained for the different experiments was lower than other published values for rice straw organosolv delignification Romani et al 2011;Sindhu et al 2012). This result can be ascribed to the very mild temperature used in this study (30 ºC) in comparison with the more severe conditions used in other organosolv studies, e.g.…”

Alkaline Pretreatment of Banana Stems for Methane Generation: Effects of Temperature and Physicochemical Changes

“…Increasing amounts of hydrolysis of the glycosidic linkages under harsher NaOH catalyzed conditions in the accessible regions of the cellulose fibers resulted in an increase of CI, and it was also presumably related to the removal of amorphous substances, hence increasing the fraction of crystalline polymer. The same trend in CI with temperature has been observed previously, for example, with pretreatment of mustard with NaOH (Sindhu et al 2012;Yang et al 2014;Kapoor et al 2015). However, the opposite trend with temperature was observed with wheat plant (grain and straw) pretreated with NaOH (He et al 2008;Taherdanak and Zilouei 2014).…”