Efficient deconstruction of Chinese silvergrass by FeCl3-catalyzed γ-valerolactone/water system under mild reaction condition

Abstract

In this work, γ-valerolactone (GVL) pretreatment using FeCl3 as a catalyst under mild temperature (120 °C) to facilitate efficient deconstruction and saccharification of Chinese silvergrass (CS) was reported. The pretreatment resulted in significant xylan and lignin removal of CS and the highest xylan and lignin removal reaching 84.3 % and 68.7 % at FeCl3 concentration of 100 mM. No obvious change in the crystalline structure of cellulose was observed under the mild pretreatment condition. X-ray photoelectron spectroscopy analysis indicated that the FeCl3-catalyzed GVL pretreatment caused poorer lignin but richer carbohydrates on the CS surface due to the increased O/C ratio in CS (increased from 0.23 to 0.63). The results indicated that the pretreatment could facilitate the decrease of non-productive adsorption of enzyme and was beneficial for the enzymatic saccharification of pretreated CS, and a high glucose yield of 99.7 % was achieved by cellulases and Tween 80.