AlCl3 catalyzed conversion of hemicellulose in corn stover

Abstract

The selective conversion of the hemicellulose in corn stover (stalk) by AlCl 3 as catalyst under hydrothermal conditions at low temperature was investigated. The effect of reaction temperature, reaction time, and AlCl 3 amount was investigated. The biomass samples before and after reaction were characterized by chemical titration, X-ray diffraction, and scanning electron microscopy. The conversion of the hemicellulose in the corn stover at 140 °C for 1 h reached 85.1%, while keeping a high proportion of the cellulose and lignin components unreacted with the conversions of 10.7% and 23.9%, respectively. Xylose and a small amount of acetic acid, and furfural were obtained from the filtrate from the hemicellulose conversion. Further reaction of the filtrate significantly improved the conversion of xylose. This was performed in a H 2 O-tetrahydrofuran solvent system, and large amounts of levulinic acid, formic acid, and furfural were obtained. The γ-Al 2 O 3 /SO 4 2− solid acid catalyst selectively promoted the formation of furfural in the H 2 O-tetrahydrofuran solvent system. The selective conversion of the hemicellulose in corn stover was achieved using AlCl 3 as the catalyst under hydrothermal conditions. γ-Al 2 O 3 /SO 4 2− efficiently catalyzed the formation of furfural in a H 2 O/THF system used for the further reaction of the filtrate.