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

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 liquefaction conditions, including glycerol/methanol ratio, liquefaction 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 addition of a sufficient amount of water. By Fourier transform infrared (FT-IR), the water soluble content mainly contained glycerol and its derivate and carbohydrate degradation products, and the precipitate content was mainly lignin derivatives.