Extraction of the sulfon oxidates in deep desulfurization of diesel

The polar organic solvents were used to extract sulfon oxidates in the catalytic oxidative desulfurization of diesel. Among these solvents, N, N-dimethylformamide (DMF) was of the best extraction effect. Furthermore, the power ultrasound and constant temperature oscillation were introduced to the extraction process in order to enhance the extraction effects. The effects of extraction solvent dosage, i.e. the volume ratio of solvent to oil, and the main technical parameters of both operating conditions on the extraction desulfurization ratio were investigated. Thus the optimal operating conditions were given. The results showed when volume ratio of diesel to extract (DMF) was 1, the total sulfur mass fraction of diesel could be reduced from 1703 μg/g to 74.8 μg/g in the extraction under power ultrasound condition(500 W, 59 kHz, 20 min); the total sulfur mass fraction of diesel could be reduced from 1703 μg/g to 116.0 μg/g in the extraction under constant temperature oscillation condition(180 r/min, 40°C, 40 min).