The Evaluation of Two-stage Chemical Fractionation for the Enhanced Enzymatic Saccharification of Cellulose in Rice Straw

Abstract

Rice straw, an agro-residue, can be utilized as a renewable resource for the production of fuel and chemicals. This study evaluates a two-stage chemical pretreatment (dilute acid hydrolysis followed by alkaline-peroxide delignification) for fractionation and enhancing the enzymatic saccharification of the rice straw cellulose to produce fermentable sugars. The process led to 100% hemicellulose dissolution and resulted in a solid residue with ~95% pure cellulose. Enzymatic saccharification of this cellulose liberates 70% more reducing sugars compared to other single-step pretreatment methods. The combined two-stage chemical pretreatment followed by enzymatic saccharification process resulted in 40.6 g/L reducing sugars from rice straw.