Correlation between Physicochemical Properties and Enzymatic Digestibility of Rice Straw Pretreated with Cholinium Ionic Liquids

Abstract

Ionic liquid (IL)-based lignocellulosic biomass pretreatment has attracted growing interest recently. In this work, cholinium ILs, a type of bio ILs composed totally of renewable biomaterials, were used to pretreat rice straw, and various physicochemical properties of the pretreated biomass including the morphological structure, biomass composition, biomass crystallinity, surface area and pore volume were studied. These physicochemical properties were correlated with the polysaccharide enzymatic digestibility (21–99% for cellulose and 9–83% for xylan). All the physicochemical properties examined exerted significant effects on the enzymatic hydrolysis of rice straw. Among these physicochemical features, surface area and pore volume were the principal factors affecting the polysaccharide digestibility. These physicochemical properties appeared to be intercorrelated, which could be converted into a linearly uncorrelated variable (the first principal component, PC1) by principal component analysis (PCA). PC1 ...