Extraction Removal Of Thiophene From Simulated Sulfur-rich Oil

The Motor Gasoline Standards of National V has been carried out since January 1,2017.The traditional hydrodesulfurization process has some disadvantages such as high hydrogen consumption,high energy consumption and non recyclability of thiophene.Extractive desulfurization technology has become a research hotspot due to the mild operation conditions and simple operation.Thiophene with market price of 50,000 RMB per ton is a good pharmaceutical intermediate and has significant importance in pharmaceutical manufacturing process,while thiophene accounts for about 70% of the total sulfur content in gasoline.It is of practical significance how to effectively recover thiophene from oil products on the basis of FCC gasoline extractive desulfurization.The effects of 12 kinds of solvents,combinations of different solvents,different proportions of composite solvents and different adjuvants on desulfurization rate,oil loss rate,solvent loss rate and selectivity were investigated.Then,the extraction experiments of different temperatures and solvent-oil ratios were performed.The experimental results showed that the desulfurization rates of dimethyl sulfoxide(DMSO)and sulfolane sulfoxide(SF)were 53.51% and 47.36%,respectively,while 1.13 of selectivity coefficient of SF was higher than that of DMSO with 1.04.To composite solvents,50.92% of single-stage desulfurization rate and 1.37 of selectivity coefficient of50% SF + 50% DMSO were higher than that of SF.Compared to DMSO,although the desulfurization rate decreased a little,the selectivity coefficient increased from 1.04 to 1.37 with 26.92% of growth rate.The desulfurization rate of DMSO + 10% A2-2-5 was 48.23%,and the selectivity coefficient was 1.24.When adjuvants of water,monoethanolamine(MEA),diethanol amine(DEA),triethanolamine(TEA),L55,L53,P3-5 and A2-2-5 were added into the single solvents,the desulfurization rate and oil loss rate decreased to some extent,but the selectivity coefficient increased.Considering desulfurization rate and selectivity,DMSO+10%MEA is the best with 49.59% of desulfurization rate and 1.4 of selectivity coefficient.When composite adjuvants of MEA+A4-3,MEA+TL05,A2-2-5+A4-3,A2-2-5+TL05,A2-2-5+BK-05,and A2-2-5+water were added into the single solvents,the desulfurization rate and oil loss rate decreased to some extent,but the selectivity coefficient increased.However,considering desulfurization rate and selectivity,the effect of adding composite adjuvants in single solvents were worse than DMSO+10%MEA.Adding water into SF:DMSO=5:5 could improve the selectivity coefficient,and 2.5% amount of water is suitable.Considering desulfurization rate and selectivity,the effect of adding water in composite solvent is worse than SF:DMSO=5:5 or DMSO + 10%MEA.In general,considering desulfurization rate and selectivity,DMSO +10%MEA and 50%SF + 50%DMSO could be regarded as the best extractants.Finally,The optimum condition of DMSO+10% showed that the optimum ratio of solvent to oil is 1.5:1,and the selectivity coefficient and desulfurization rate of DMSO+10%MEA were slightly higher 50%SF+50%DMSO or SF.