关键词: 高酸原油, 环烷酸, 咪唑, 离子液体

Abstract: A basic deacidification agent, imidazole in ethanol solution, was used to remove naphthenic acids from various acidic crude oils by forming ionic liquids, which could be easy to be separated from crude oil due to their significant differences in polarities. The effects of imidazole content in ethanol, reagent/oil ratio, reaction time, reaction temperature and blending intensity on the acid removal rate were studied and optimum reaction conditions of single stage extraction were obtained. Four crude oils with acid number from high to low in the order of Beijiang crude  Penglai crude  1# blending crude  2# blending crude were involved in the study. Results showed that under the conditions of an imidazole content of 30%, a reagent/oil ratio of 0.4, a reaction time of 5 min, a reaction temperature of 30℃ and with a blending intensity of 300 r/min, the 1-stage acid removal rates of Beijiang crude, Penglai crude, 1# blending crude and 2# blending crude were 61.5%, 68.6%, 70.6% and 72.2%, respectively. When 3-stage countercurrent extractions were carried out for these four crude oils, the acid removal rates at a reagent/oil ratio of 0.4 and 0.6 reached about 75% and more than 84%, respectively.

Key words: acidic crude oil, naphthenic acid, imidazole, ionic liquids