风城稠油中石油酸组成结构分析

由氢氧化钾-乙醇水溶液分离风城稠油中的石油酸,结合元素分析、红外光谱(FT-IR)、核磁共振(NMR)、电喷雾质谱(ESI-MS)、紫外光谱(UV-Vis)和荧光色谱等方法分析其结构组成。结果表明:风城稠油所含石油酸主要是一元羧酸二聚体,平均相对分子质量为665,平均分子式为C43.51H78.47O3.78,氢碳原子比为1.80;各类酸分布范围较广,其中,环烷酸含量最高,占79.84%,脂肪酸次之,占20.16%;环烷酸中一环环烷酸、二环环烷酸、三环环烷酸、四环环烷酸/芳环羧酸、五环环烷酸/芳环并一环羧酸和六环环烷酸/芳环并二环羧酸的含量相当,均在11.00%~18.88%之间。此外,还检测到微量3~4环的芳香结构物质。

COMPOSITIONS AND STRUCTURES OF PETROLEUM ACIDS IN FENGCHENG HEAVY CRUDE

Petroleum acids in Fengcheng heavy crude were separated by potassium hydroxide-ethanol aqueous solution extraction. The compositions and structures of petroleum acids were determined by elemental analysis, IR, NMR, ESI-MS, UV and Fluorescence Spectrum. The results show that the petroleum acid in Fengcheng heavy crude is mainly composed of dimers of mono-carboxylic acids with an average molecular weight of 665, the empirical formula is C43.51H78.47O3.78 with a hydrogen-carbon mole ratio of 1.80. The contents of naphthenic acids and aliphatic acids occupy 79.84% and 20.16%, respectively. The contents of naphthenic acids with different structures (including 1-3 ring naphthenic acids, 4-ring naphthenic acids/aromatic carboxylic acids, 5-ring naphthenic acids/benzonaphthenic carboxylic acids with one ring, 6-ring naphthenic acids/benzonaphthenic carboxylic acids with 2-ring) are close to each other, ranging from 11.00% to 18.88%. Trace amount of 3-4 ring aromatic in petroleum acids are also observed.