Study on γ-valerolactone/1-octanol as green solvent for catalytic liquefaction of woody biomass

The solvent has an important impact on liquefaction conversion from biomass to efficiently obtain fuels and chemicals. In this paper, the catalytic liquefaction of woody biomass was studied using fir sawdust as raw material and concentrated sulfuric acid as catalyst in GVL/1-octanol mixed solvent with mechanical stirring and oil bath heating. The influence of GVL on liquefaction yield was discussed, and the liquefaction productions were characterized by some analysis methods to analyze the liquefaction mechanism. The results show that adding GVL benefits to improving liquefaction yield and generating high value-added monophenol because of the enhancement of the surface wettability of biomass and the inhibition of polymerization of mononuclear aromatics with other degradation products. The maximum liquefaction yield of 76.07% was obtained under the suitable conditions of fir sawdust 10 g, temperature 150 degrees C, reaction time 60 min, mass ratio of sawdust/solvent 1:6, catalyst concentration 0.6 mol.L-1, and mass ratio of GVL/1-octanol 4:6. The mechanism study reveals that aromatics originated by lignin degradation as well as small molecule ketones from cellulose and hemicellulose degradation. GVL/1-octanol as an eco-friendly solvent system exhibits a promising prospect of application in woody biomass conversion.