Experimental study on the performance of microwave assisted Hydrogen peroxide (H2O2) pretreatment of rice straw

Abstract

Biofuels are essentials as they can provide impending substitute for fossil fuels.  Rice straw has gained much attention from researchers because of its usability as a potential feedstock for bioethanol production.  Pre-treatments are crucial for enzymatic hydrolysis of rice straw.  In this study, combination of microwave and hydrogen peroxide (H₂O₂) is employed for the delignification of rice straw.  The Response surface methodology is used to optimize the pretreatment conditions with respect to H₂O₂ concentration, microwave power and irradiation time.  Under optimum conditions, maximum reducing sugar obtained through microwave assisted H₂O₂ is 1,453.64 µg/mL.  The chemical and morphological analysis ascertained that the surface of the samples treated with microwave assisted H₂O₂ was more ruptured and has a significantly high crystalline index (63.64%) than untreated rice straw sample (52.2%).  Microwave assisted H₂O₂ pre-treatmentdisrupted the silicon waxy structure and broken down allether linkages between lignin and carbohydrates and thus, efficiently remove lignin.  The present study proves that microwave assisted H₂O₂ is an effective pretreatment technique for the conversion of rice straw into bioethanol production by enhancing enzymatic saccharification.

Keywords: pre-treatment, enzymatic hydrolysis, rice straw, biofuel, microwave, hydrogen peroxide