Abstract: Poplar, Chinese fir, bamboo, rice straw, and hemp xyloid stem were selected to investigate the effects of species on microwave-assisted liquefaction behaviors in polyhydric alcohols. Among the five types of biomass feedstocks, poplar and Chinese fir were easily liquefied, and bamboo and hemp xyloid stem were more difficult to be liquefied than poplar and Chinese fir. But rice straw was the most difficult to be liquefied. While the hydroxyl value of liquefied products(LP) of rice straw was the highest and that of Chinese fir was the lowest. It was found that both extract benzene-alcohol content and ash content had strong side effects on microwave-assisted biomass liquefaction. When the ratio of polyhydric alcohol to biomass was 2.5 and 3, co-liquefied fraction of mixed biomass of poplar, Chinese fir, bamboo, and hemp xyloid stem were 91% and 95%, respectively. This was notably higher than the yield of single bamboo and hemp xyloid stem. The hydroxyl value of LP of mixed biomass was close to that of bamboo. And its chemical components differed significantly from hemp xyloid stem. It would conclude that the synergistic effect exited in the co-liquefaction of mixed biomass feedstock.

Key words: biomass species, microwave heating, liquefaction in polyhydric alcohols, co-liquefaction