Effect of Simultaneous Steam Explosion and Alkaline Depolymerization on Corncob Lignin and Cellulose Structure

Abstract

Simultaneous steam explosion and alkaline depolymerization was studied to develop an economic and green process for alkaline pretreatment of lignocellulose. Steam explosion facilitated alkaline delignification and decreased the amount of alkali used during pretreatment. Different amounts of lignin and hemicellulose were removed within 5 min by using different sodium hydroxide concentrations and steam explosion severity. The main component of lignin collected using our simultaneous process was acid-insoluble lignin, reaching a purity of 84 %. Structural analysis indicated that steam explosion and sodium hydroxide had a synergistic effect on the removal of lignin and hemicellulose from corncob. The effect to four simultaneous pretreatment process of delignification transformed cellulose I to cellulose II, enhancing the enzymatic conversion of cellulose to glucose from 22 % to 96 %. The process of simultaneous steam explosion and alkaline depolymerization shows a potential for application in the lignocellulose biorefinery.

Keywords

• lignin
• steam explosion
• alkaline depolymerization
• cellulose
• enzymatic hydrolysis