Abstract: It is easier for the decarboxylation reaction of unsaturated fatty acid salt. The Chinese tallow seed oil was saponified by lithium hydroxide，sodium hydroxide，potassium hydroxide. Different saponificated Chinese tallow seed oils were used as model compounds to study the decarboxylation leading to hydrocarbon formation via microwave-assisted pyrolysis technology，the pyrolysis products were analyzed by GC-MS and FT-IR. Microwave energy was able to selectively heat the carboxyl terminal of saponificated Chinese tallow seed oil. During decarboxylation，the double bond in the long hydrocarbon chain formed a P-? conjugated system with the carbanion intermediate. The resulting P-? conjugated system was more stable and beneficial to the pyrolysis reaction (decarboxylation，terminal allylation，isomerization，and aromatization). The saponificated oil has a stronger polarity，the heating rate is higher，liquid hydrocarbon yield is bigger. The viscosity(2.10―2.55 mm2/s) and density(0.825―0.865 g/cm3) of the pyrolysis liquid obtained from this experiment were similar to those of diesel. It was proved feasible to derive renewable hydrocarbon fuel from saponificated Chinese tallow seed oil by microwave-assisted pyrolysis.

Key words: Chinese tallow seed oil, saponificated, microwave, decarboxylation, hydrocarbon fuel, renewable energy

摘要： 不饱和脂肪酸盐微波极化条件下更容易脱羧成烃，本研究分别以氢氧化锂、氢氧化钠、氢氧化钾皂化乌桕油，以不同碱金属乌桕油皂化物和乌桕油为研究对象，在恒定的微波功率下裂解脱羧成烃，通过GC-MS等分析裂解产物，微波能选择性地加热乌桕油皂羧基端，不饱和键在微波极化过程中与碳负离子中间体形成P-?共轭体系，使裂解反应（脱羧、端烯化、异构化和芳构化等）顺利进行。皂化物极性越大，升温速率越快，液体烃类产率越高，脱羧效果越明显，裂解液体的密度为0.825～0.865 g/cm3，黏度为2.10～2.55 mm2/s，与柴油的性质非常相似，从而证明微波极化乌桕油皂脱羧制烃类燃料的可行性。

关键词: 乌桕油脂, 皂化, 微波, 脱羧, 烃类燃料, 再生能源