Optimized yield of fermentable sugar from chemical hydrolysis of rice straw for application in ethanol fermentation

Abstract

Lignocellulosic biomass is a rich source of carbohydrate polymers with cellulose and hemicellulose being the two primary carbohydrates made up of glucose and xylose monomers. These monomeric sugar molecules act as precursor molecules for ethanol production by the microbial fermentation process. Rice straw is a potent lignocellulosic feedstock for ethanol production, but its utilization on an industrial scale still faces significant challenges. The main obstacle lies in the chemical pretreatment process which needs to be designed optimally to enable a smooth supply of biomass-based fermentable sugar for ethanol businesses in a sustainable and cost-effective manner. The application of response surface curve analysis was made utilizing the Minitab software-based design of experiments which have demonstrated promising results in obtaining an optimized yield of fermentable sugar from the chemical hydrolysis of rice straw. The present study aimed to increase the fermentable sugar yield from chemical pretreatment of rice straw using Minitab computer software-based design of experiments. The optimal level of pretreatment variables was determined using Minitab 17 software-based analysis of the response surface curve to achieve a maximized release of fermentable sugar at 348.20 milligrams/gram of solid pretreated biomass. This study identified the corresponding optimum operating levels for each variable as (a) biomass solid loading rate (15% w/v), (b) H2SO4 concentration (12% v/v), (c) pretreatment reaction time (30 minutes) and (d) temperature (100°C).