Cellulose Depolymerization By Hydrothermal Process Using Ionic Liqud/Acid

Abstract

Cellulose is natural polysaccharide formed from D-glucose units, which are linked through β(1→4)-glycosidic bonds. For wider industrial applications, cellulose is depolymerized to produce reducing sugar such as glucose, fructose and others. The common method  to depolymerize cellulose is acid hydrolysis, ionic liquid, and hydrothermal process. The aim of this research is to study the effect of reaction time in hydrothermal process using sodium chloride (NaCl) as ionic liquid analog and oxalic acid as catalyst in cellulose depolymerization to produce reducing sugar. In this study, hydrothermal process has been done in subcritical condition at 70 bar and 185^oC in various reaction time (30-180 minutes) using nitrogen gas as pressurizing agent. After hydrothermal process, the sample was separated as liquid and solid product. The solid product was analyzed using XRD. And liquid product was analyzed by di-nitrosalicylic acid (DNS) method  to determine  the reducing sugar concentration. The results show that reducing sugar was increase in 60-120 minutes and decrease in 150 and  180 minutes. The highest reducing sugar was achieved at 60 minutes (0,324 mg/mL).