Optimization of alkaline peroxide pretreatment of rice straw

Abstract

Lignocellulose represents a promising starting material for conversion to fuels and chemicals in biorefinery; however, its efficient conversion to sugar requires a prerequisite pretreatment step. In the present research, the pretreatment of rice straw by alkaline peroxide pretreatment was studied aiming to enhance enzymatic digestibility of the cellulose-enriched solid. The alkaline hydrogen peroxide (AHP) pretreatment of rice straw using different concentration of hydrogen peroxide, reaction time, temperature, and solid loading were evaluated based on enzymatic digestibility and sugar recovery. The highest reducing sugar recovery was in the range of 499±6 mg/g native biomass after pretreatment using 2.5% H₂O₂ (v/v) at 35 ?C for 24 h and 7.5% biomass loading (w/v) after enzymatic hydrolysis using 20 FPU/g Accellerase^® 1500. The work demonstrates the potential of the developed process for low temperature pretreatment of biomass for further conversion to value-added products.  

Keywords: rice straw, biorefinery, alkaline peroxide pretreatment