Extractive dearomatization, denitrification and desulfurization of gas oil fractions by a mixed extractant of N,N-methylpyrrolidone, N,N-dimethylformamide and ethylene glycol via microwave radiations

In an attempt to develop alternative process that meet the prescribed levels and green-technology criteria in gas-oil refining, N,N-methylpyrrolidone (NMP), dimethylformamide (DMF) mixed solvents under microwave-radiations (MW) were tested for the gas-oil desulfurization (EDS), denitrification (EDN) and dearomatization (EDA). In optimal conditions the gas-oil EDS-efficiency via MW can reach as high as 99.1% within 5 min at 500 W in three stages, which is much higher than EDS without MW (88.5% within 15 min) or than those of ionic liquids. The NMP/DMF/EG can be reused for multi-cycles before being regenerated by adsorption method. This study will provide useful information for future industrial application.