Comparison of extraction properties of ethylene glycol and dimethyl sulfoxide in the process of extraction of aromatic hydrocarbons from the gasoline fraction

The use of gasoline fractions as a raw material for pyrolysis for the production of olefins is economically feasi-ble. However, the content of aromatic hydrocarbons in them reduces the selectivity of the process for ethylene and propylene and intensifies coke formation. Pre-dearomatization is a necessary technological process to intensify pyrolysis and ensure stable operation of the equipment. The article presents a study of the process of extractive dearomatization of the gasoline fraction using ethylene glycol and dimethyl sulfoxide by establishing the influence of a key parameter – the ratio “solvent : feed ratio” – on the process parameters. The study was carried out on a laboratory extraction system of periodic action. The hydrotreated straight-run gasoline fraction was used as the raw material. It has been established that the optimal ratio for the extraction of aromatic hydrocarbons from the straight-run gasoline fraction is 1.5 : 1 “solvent : feed ratio”, at which the maximum degree of extraction of aromatic hydrocarbons is achieved: 62.86% for ethylene glycol and 68.57% for dimethyl sulfoxide. A further increase in the solvent fraction leads to a decrease in cleaning efficiency and an increase in energy consumption for regeneration. It is shown that the developed process using water-modified solvents has an efficiency comparable to industrial analogues with potential advantages in cost and regeneration conditions, which confirms its practical value for increasing the profitability of extraction processes.