Ionic liquid extraction as an effective alternative in the process of dearomatization of petroleum oils

Rational use of petroleum products and environmental protection are considered problems of our time, the main solution to which is the eco-friendly way of extracting unwanted aromatic compounds from petroleum products and, in turn, their effective use in various fields. Ionic liquids, due to their unique complex properties, play a key role in the creation of clean technologies for refining petroleum products. The presented article gives the results of studies on the purification of transformer oil distillate T-1500 containing 24% mass of aromatic compounds in order to obtain a dearomatized product - raw material for the synthesis of synthetic naphthenic acids. The process of extracting aromatic hydrocarbons was carried out by the extraction method using ionic liquid - N-methylpyrrolidonium acetate - as an environmentally friendly solvent at a temperature of 60 °C and an extraction time of 1 hour, either in one stage with a ratio of oil distillate to ionic liquid equal to 1: 1÷3, so and stage by stage using equal amounts of extractant and distillate at each stage. The effectiveness of stage-by-stage ionic-liquid extraction purification of transformer oil and the possibility of obtaining dearomatized distillate with a degree of 87.5% mass and a yield of 70.15% mass of the target product during three-stage purification have been established. UV spectral analysis of the dearomatized oil in comparison with the original distillate showed a decrease in the content of benzene and phenanthrene derivatives by 7.4 and 12.3 times, respectively, and the complete removal of tricyclic aromatic hydrocarbons. Keywords: Ionic liquid; T-1500 transformer oil; aromatic hydrocarbons; purification by extraction method.