Bioethanol productions from rice polish by optimization of dilute acid pretreatment and enzymatic hydrolysis

Abstract

Lignocellulose materials are abundant renewable resource for the production of biofuel from fermentative organism (Sacchromyces cervesiae). Rice polish is cheapest and abundant lignocelluloses resource and has potential to produce bioethanol. The main steps for the conversion of biomass into glucose required dilute acid pretreatment, but it also released inhibitory compounds which reduced the ethanol yield. So, attempt has been made to minimize the effect of inhibitory compounds as well as optimized the condition like glucose recovery, xylose solubilization and lignin degradation during dilute acid pretreatment. Maximum lignin degradation, less glucose loss, better xylose solubilization obtained with dilute sulphuric acid 1.5% at 100°C for 30 min. During enzymatic hydrolysis (Novozyme) with 0.75 mL/2 g, enzymatic loads for 72 h gave 4.27mg/mL glucose while with indigenous enzyme load 1 mL/2 g gave 0.953 mg/mL of glucose.

Key words: Bioethanol, Dilute acid pretreatment, enzymatic hydrolysis, rice polish.