Comparative study of hydrothermal pretreatment for rice straw and its corresponding mixture of cellulose, xylan, and lignin

Abstract

We herein investigated the effect of hemicellulose and lignin on the hydrothermal pretreatment of lignocellulosic biomass for glucose production from cellulose in terms of structural cross-linking between cellulose and the above components. A comparison was made between the hydrothermal pretreatment of biomass and a mixture containing the individual model compounds in the same composition ratio. Thus, rice straw biomass and the mixture containing cellulose, xylan, and lignin were treated in an autoclave reactor at temperatures between 150 and 250 °C for 30 min. The obtained products were then subjected to enzymatic hydrolysis. Interestingly, different results were obtained for the two samples, as the presence of cross-linking between cellulose and lignin in the original biomass sample affected the efficiency of hydrothermal pretreatment. A model was therefore proposed to account for the obtained result in accordance with previous knowledge regarding the behavior of these compounds under hydrothermal conditions.

Keywords: Cellulose; Hemicellulose; Hydrothermal pretreatment; Lignin; Rice straw; Xylan.