Separation of Cellulose from Rice Hull

Abstract

Rice hull was proposed as an alternative raw material for cellulose production. Rice hull has cellulose (38.6+/-0.1%), xylan (12.8+/-0.1%), lignin (22.7+/-0.7%), extractives (7.9+/-0.4%), and inorganic (13.2+/-0.8%).Inorganic was selectively removed using moderate alkaline extraction, and lignin was degraded via oxidation with chlorine dioxide or hypochlorite. In this study, dilute acid hydrolysis was used to selectively remove hemicellulose, resulting in purer cellulose and better yield. Xylan was selectively removed using sulfuric acid at various acid concentrations (0.25–1 N), reaction time (60–120 min), and temperature (100–120°C) with desilicated and delignified biomass. The reaction conditions for ＞90% cellulose purity were 120°C and 1.0 N sulfuric acids. Increasing the reaction duration resulted in higher cellulose purity, with the greatest purity being 96.1% at 1.00 N sulfuric acid, 120°C, and 120-min reaction time.