Enhancement of the enzymatic hydrolysis of wheat straw by pretreatment with 1-allyl-3-methylimidazolium chloride ([Amim]Cl)

Abstract

The enhancement of the enzymatic hydrolysis of lignocellulose by pretreatment is a key difficulty in biomass utilization. Wheat straw was treated with 1-allyl-3-methylimidazolium chloride ([Amim]Cl), and the morphology, enzymatic hydrolysis, recovery and the content of the composition of the treated wheat straw were investigated. Significant morphological change was observed when the wheat straw was heated at 150°C. When the temperature increased from 125 to 150°C, the glucose yield after enzymatic hydrolysis increased from 0.13 to 0.23 g/g (within 2 h). When the wheat straw was treated at 150°C for 6 h, the recovery of solid was only 23.9%, and the contents of cellulose, hemicellulose and lignin were 46.7, 10.8 and 24.2% respectively. It was concluded that heating with [Amim]Cl is an efficient pretreatment method; too intense treatment condition would induce degradation of wheat straw and the suitable condition of pretreatment is 150°C and 2 h.

Keyword: Ionic liquid, [Amim]Cl, wheat straw, pretreatment, cellulose, cellulase, enzymatic hydrolysis