Atmospheric distillation of bio-oil based on different extractants

In order to separate and enrich the high value-added chemicals in bio-oil, solvent extraction and distillation methods were combined to separate and purify bio-oil. Ethyl-acetate, dichloromethane, diethyl ether and toluene were elected as extracting agents, which were mixed with bio-oil in a certain mass ratio. The 4 oil phases distilled from four extract phases were compared with bio-oil to study effects of different solvents on the yield, moisture and high value-added components of distillate. The results show that the distillate had higher yield and lower moisture content compared with that of bio-oil after the extraction and distillation. Among the 4 solvents, toluene had the poorest ability to extract high value-added components of bio-oil, achieving the lowest yield of phenols of distillate. The extraction efficiency of ethyl-acetate and diethyl ether was higher than that of toluene, but the contents of high value-added components in their oil phases were lower than those of others. The relative content of guaiacol and its derivatives was 34.11% in the oil phases of dichloromethane, which was 15.52% higher than that of bio-oil, and conducive to further extract for high value-added chemicals such as guaiacol and its derivatives.