Study On The Application Of Acidic Eutectic Solvents And Their Supported Catalysts In Oil Desulfurization

The burning of refined oil will produce sulfur-containing gas,which is the culprit of acid rain and endangering human health.Most countries have put forward stricter limits on the sulfur content in fuel oil.However,the current hydrodesulfurization technology has disadvantages such as harsh reaction conditions for some highly hindered sulfides,such as thiophene sulfides.As one of the oxidative desulfurization catalysts,the acidic eutectic solvent and its supported catalyst can take advantage of the high electron cloud density of thiophenes in oils to oxidize them,and then achieve efficient removal of sulfides in oils.In this paper,the acidic eutectic solvent and its supported catalyst were prepared by simple heating or sol-gel process,and applied to the oxidative desulfurization process.（1）A zirconium oxychloride-based eutectic solvent is synthesized by heating a mixture of acetamide and zirconium oxychloride octahydrate in a certain molar ratio.Infrared spectroscopy and hydrogen spectroscopy were used to confirm the existence of hydrogen bonds.The optimal reaction conditions were determined by investigating the reaction conditions.Under these conditions,the removal rate of dibenzothiophene was 98.6%.The desulfurization rate of the catalyst is still above 90%after using the catalyst for 5 times,indicating that the zirconium oxychloride eutectic solvent has good recycling performance.（2）Using zirconium oxychloride-based eutectic solvent as an additive component,different eutectic solvent-loaded silica gels are prepared through a sol-gel process.Through infrared spectroscopy and X-ray electron diffraction,it was confirmed that the eutectic solvent was loaded on silica gel,and the morphology of the catalyst was confirmed by scanning electron microscopy.The N₂-adsorption and desorption technology was used to determine the specific surface area,pore size and pore volume of the catalyst after the active components were loaded.The supported silica gel was used as adsorbent and catalyst,and hydrogen peroxide was used as oxidant to investigate the removal effect of sulfide in simulated oil,and the optimal reaction conditions of the system were determined.Under these conditions,the removal rate of dibenzothiophene was 98.6%,the removal rate of 4,6-dimethyldibenzothiophene is 98.4%,and the experiment of recycling performance shows that the desulfurization rate only slightly decreases after 5 cycles of use.（3）Synthesize n-octanoic acid-zinc chloride-based eutectic solvent,and then use it as an additive component to obtain the silica gel supported by the eutectic solvent through the gel-sol process.Through infrared spectroscopy and X-ray electron diffraction,it was confirmed that the n-octanoic acid-zinc chloride-based eutectic solvent was loaded on silica gel,and the morphology of the catalyst was confirmed by scanning electron microscopy.The N₂-adsorption and desorption technology was used to determine the specific surface area,pore size and pore volume of the catalyst after the active components were loaded.The supported silica gel was used as adsorbent and catalyst,and hydrogen peroxide was used as oxidant to investigate the removal effect of sulfide in simulated oil,and the optimal reaction conditions of the system were determined.Under these conditions,the removal rate of dibenzothiophene was 95.6%,experiments show that the catalyst has good recycling performance.