Study On The Extraction And Desulfurization Process Of Alkane Solvent Oil With Alkanolamine-based Deep Eutectic Solvent

The SO_x generated after the burning of fuel will cause great harm to the ecological environment and people's health.Therefore,domestic and foreign laws set strict standard on the sulfur content of fuels.Hydrodesulfurization is the mainstream desulfurization method in the industry,but its reaction conditions are harsh and require high equipment.The method of extractive desulfurization with deep eutectic solvents(DESs)has mild conditions,simple steps,and is environmentally friendly.In this paper,by preparing a series of DES for the extraction desulfurization experiments of sulfur-containing simulated oil,tetrabutylammonium bromide(TBAB)and diethanolamine(DEOA)were selected as raw materials for preparing DES.The experiment determined the synthesis of deep eutectic solvent.The optimal conditions are optimized as follows:the molar ratio of hydrogen bond acceptor to hydrogen bond donor is 1:2,the synthesis temperature is 60?,the synthesis time is 120 min and the stirring speed is 500rpm.Under these conditions,the yield of DES is 100%.The DES is used in the research of the actual sulfur-containing solvent oil extraction desulfurization process.Firstly,the single-stage extraction method was used to carry out the desulfurization experiment,and the influence of single factor on the desulfurization process was investigated.After optimization,the optimal extraction condition is:the solvent ratio is 1 1?the stirring speed is 1000 rpm?the extraction time is 120 min and the extraction temperature is 15?.Under these conditions,the desulfurization rate is 70.10%.Secondly,the desulfurization rate can still be maintained after the eutectic solvent is back-extracted and regenerated.Its repeatability remains basically unchanged.Finally,DES was synthesized by adding PEG as the third component,which greatly reduced the viscosity of the original DES.We applied it to multi-stage extraction desulfurization.The 6-stage cross-flow extraction desulfurization rate was99.80%,and the simulation results of 8-stage cross-flow extraction desulfurization indicates that the sulfur content can be reduced from 17945 ppm to less than 10 ppm;the desulfurization rate of 3-stage countercurrent extraction is 88.37%(for high-sulfur solvent oil)and 92.49%(for low-sulfur solvent oil).The simulation result of 9-stage countercurrent extraction desulfurization indicates that the sulfur content can be reduced from 17945 ppm to less than 100 ppm.