Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtu

Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of lique-faction conditions, including glycerol/methanol ratio, liq-uefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120 °C, the reaction time of 7 min, the glycerol–methanol–bamboo ratio of 8/0/2 (W/W), and the microwave power of 300 W. Maximum conversion yield was 96.7%. The liquid products were separated into two contents (water soluble part and precipitate part) by addi-tion of a sufficient amount of water. By Fourier transform infrared (FT-IR), the water soluble content mainly con-tained glycerol and its derivate and carbohydrate degra-dation products, and the precipitate content was mainly lignin derivatives.