EXTRACTION PURIFICATION OF HEAVY DELAYED COKING GAS OIL USING THE N-METHYLPYRROLIDONE – HEPTANE SYSTEM

The article presents the results of the extraction purification of heavy delayed coking gas oil with mass ratios of N-methylpyrrolidone with 2 % mas water to raw materials as 0.5 : 1, 0.75 : 1, 1 : 1, and in the presence of heptane at mass ratio to raw materials as 0.3 : 1 and temperature of 40 оC. It was found that the introduction of heptane into the extraction system with N-methylpyrrolidone leads to an increase in the yield of raffinate due to an increase in the selectivity of the release of polyaromatic hydrocarbons. However, due to the presence in the gas oil of delayed coking of sulfur compounds of not only aromatic nature, but also saturated thiacyclanes and dialkylsulfides forming systems close to ideal with heptane, the efficiency of gas oil desulfurization decreases.