阿尔巴克拉高酸原油的石油酸结构分析

以阿尔巴克拉原油为模型,对高酸原油中石油酸分子的结构进行了研究。对其进行实沸点蒸馏分析,表明间歇蒸馏过程中部分石油酸类化合物在受热过程中会发生脱羧反应,不利于分子结构特性的研究。借助高分辨质谱、红外光谱对常减压装置中馏分油的酸性氧化物进行了组成及结构分析,认为相对丰度均为:O2>O1>N1O2>N1O1>N2O1;各馏分油中O2类石油酸化合物分子的等价双键数(DBE)值范围在1~19,碳数范围在C10~C54;丰度较高的化合物分子碳数集中在C25~C30之间,DBE值为2~4附近;采用碱醇液萃取的方法对环烷酸进行了富集和红外光谱分析,推断原油及馏分油中存在的石油酸分子以环烷酸类为主,羧基连接在环烷酸的侧链上且侧链的碳数一般不超过5。

Analysis of naphthenic acids in Albacro crude oil with high acid number

An experiment of petroleum acid molecular structure and true boiling point distillation was per formed for Albacro crude oil. It shows that part of the acids compounds undergoes decarboxylic reaction during the heating process of batch distillation, which is not favorable for the investigation of the molecular structures and properties. Compositions as well as structures of acid oxidates of fractions of Albacro crude oil with high acid number were characterized with the help of different spectroscopic methods such as MS and IR, and the relative abundance of these oxygenated compounds is： 02 〉 O1 〉 NIO2 〉 N101 〉 N201. The results indicate that DBE of 02 petroleum acids in different fractions generally fluctuates only between 1 - 19, and the carbon number distribution range is between C20 - C54. The carbon number of molecules of compounds with higher rel ative abundance is between C25 - C30, and DBE is close to 2 - 4. After enrichment of naphthenic acid by alka li alcohol extraction process and analysis with IR, it can be inferred that aliphatic acids have a low content and the naphthenic acids are the main acid species. Moreover, the earboxyl group exists in the side chain of the naphthenic acid and carbon number of the side chain is generally no more than five.