Removal Of Sulfides With Oxygen As The Oxidant

New legislation will require substantial reduction in the sulfur content of transportation fuels. The traditional hydrodesulfurization process is highly efficient in removing thiols and sulfides, but is less effective for thiophenes and thiophene derivatives. This is a challenge for traditional hydrodesulfurization process. The attention is paid to other nonhydrodesulfurization technologies, such as adsorptive desulfurization, abstractive desulfurization and oxidative desulfurization. Currently, oxidative desulfurization becomes the hotspot, which is investigated extensively for its mild reaction conditions, not using hydrogen, simple equipment and highly efficiency.We studied the oxidation of different sulfides in model fuels with oxygen without catalysts and solvents. The results indicated the reactivities of the substrates decrease in the order of 4,6-dimethyldibenzothiophene>dibenzothiophene>benzothiophene>thiophene. The effects of reaction temperature, time, pressure and stirring rate were studied. Then, the results showed that using water as solvent, the thiophene content can be lowered from 1000μg/g to 96μg/g after 3 hours with removal rate of 90.4% under these conditions:150℃,0.8 MPa,500 r/min and the ratio of water to oil is 3:1. The optimal conditions of removal of benzothiophene are as follows:the temperature 150℃,1 h,0.8 MPa oxygen pressure and the stirring rate is 500 r/min. The conversion of benzothiophene is 89.9%. We also studied the effects of kinds of hydrocarbon compounds on the removal of thiophene and benzothiophene, the order thiophene are influenced:ethylbenzene>cyclohexane>1-octene; they influence benzothiophene are:decalin>ethylbenzene.