Extraction of Oxidized Sulfur-Containing Compounds of Non-Hydrotreated Gas Oil

The desulfurization of non-hydrotreated gas oil using oxidation followed by liquid/liquid extraction has been studied. The solvent extraction of oxidized sulfur-containing compounds of gas oil was carried out by utilizing various types of solvents, including acetonitrile, methanol, and 96 vol.-% ethanol. The performance of these solvents was carefully evaluated and compared by considering both desulfurization and gas oil recovery. It was found that their performance follows the order: acetonitrile > methanol > 96 vol.-% ethanol. The influences of operating conditions, such as number of extraction stages and solvent to gas oil ratio, on the desulfurization and recovery of gas oil, were investigated. Over 99% desulfurization of gas oil was achieved after liquid/liquid extraction of the oxidized sulfur-containing compounds.