高酸值馏分油中环烷酸的热分解脱酸反应及机理

Decomposition of Naphthenic Acids in High Acid Number Distillates and Its Mechanisms

在高压釜中对绥中减压二、三线馏分油和辽河减四线馏分油进行了热分解脱酸反应,并采用原位红外方法研究环烷酸的热分解脱酸反应机理。结果表明,反应温度越高,环烷酸分解脱酸反应速率越快,平衡酸值越低,反之亦然。每种馏分油的分解脱酸反应均存在1个临界反应温度,高于该温度,反应速率明显增加,而且重馏分油比轻馏分油更易于分解脱酸。环烷酸在200℃以上发生热电离,当反应温度高于250℃后,热电离完全,此现象与分解脱酸温度和过程相一致,说明热分解过程是由环烷酸的热电离引起的。

The thermal decomposition of naphthenic acids in Suizhong vacuum distillations and Liaohe vacuum 4th distillation was studied in an autoclave,and the mechanism was also studied via in-situ FT-IR.The data indicated that high temperature could accelerate the decomposition speed and caused lower equilibrium acid number,and vice versa.Every distillate in the experiments showed a critical decomposition temperature.When the reaction temperature was higher than the critical decomposition temperature,the decomposition of naphthenic acids was accelerated sharply.Heavier distillates were easier to decompose than the lighter ones.The thermal ionization of naphthenic acids happened when the reaction temperature was more than 200℃,and the thermal ionization completed when the reaction temperature rose to more than 250℃,which was in accordance with the decomposition of the naphthenic acids in distillates,indicating that the thermal ionization caused the decomposition of the naphthenic acids.