生物质快速热解油水相溶液超声乳化特性

使用生物油水相溶液与0# 柴油乳化，筛选了四种常用乳化剂和一种助乳化剂进行复配乳化实验，考察了复配乳化剂型号、乳化剂用量、超声作用时间对乳化效果的影响。结果表明，六种乳化液超过30d不破乳，与0# 柴油相比，密度和热值相差不大，含水量3%以下，黏度增大约40%，pH值降低一半。因素分析法表明，水相溶液与柴油质量比和不同的水相溶液对乳化效果影响较大。探讨了乳化机理，认为生物油水相溶液中水、醛、酸、酮等极性组分化合物稳定地被乳化剂包裹在W/O型乳化液液滴中，生物油水相溶液中少量的乙酸乙酯、芳香类化合物等则增溶于非离子乳化剂胶束中。热力学分析表明,超声乳化作用比静置作用具有更大的熵增，乳化液更趋于稳定平衡状态。

Ultrasonic emulsification characteristics of aqueous solution of bio-oil from fast pyrolysis of biomass and diesel

The bio-oil from fast pyrolysis of biomass has chemical instability and high viscosity and is difficult to be emulsifid with 0# diesel. Surrounding these problems, an emulsification process, the bio-oil aqueous solution was emulsified with 0# diesel, is suggested. Four common emulsifiers and one co-emulsifier were selected and remixed to two new emulsifiers. Under certain conditions, the effect of two remixed emulsifiers, the mass ratios of remixed emulsifiers and the ultrasonic time on emulsification results were studied. The results show that the six emulsions are not broken within 30d. Compared with characteristics of 0# diesel, its density and heat value are almost the same, water content is below 3%, kinematical viscosity increases about 40%, and pH value decreases about 50%. Factor analysis shows that mass ratio of bio-oil aqueous solution to diesel and different types of bio-oil aqueous solutions are most important to influence on the emulsification. The emulsification mechanism was preliminarily discussed. Polar compounds such as water, aldehyde, acid and ketone from bio-oil aqueous solution were wrapped in W/O emulsion droplet. The compounds such as ethyl acetate and aromatic compounds were solubilized in the micelles of the nonionic emulsifiers. The thermodynamic analysis on emulsification shows that entropy increase of ultrasonic emulsification process is more than that of static bio-oil, and the emulsions tend to be equilibrium state.