Synthesis Of Acidic Ionic Liquids Catalysts Toward Catalytic Oxidative Desulfurization In Fuel

With the continuous development of the world economy and the automobile industry,the environmental problems caused by exhaust emissions have become more and more prominent.SOx emitted from diesel engine exhaust will cause air pollution,which will not only cause environmental problems such as acid rain,but also have a destructive impact on industrial production equipment.The deep desulfurization of fuel oil has become an important topic that has attracted worldwide attention.Hydrodesulfurization in fuel needs to be carried out under high temperature and high pressure,and the operating conditions are severe.The removal effect of thiophene sulfides is not ideal.For this reason,other non-hydrodesulfurization technologies have been developed,including oxidative desulfurization,adsorption desulfurization,alkylation desulfurization and extraction desulfurization.Oxidative desulfurization has attracted much attention because of its mild operating conditions,good desulfurization effect,and low investment in cost.In this paper,a series of acidic ionic liquid based catalysts were synthesized and applied to catalytic oxidative desulfurization in fuel.（1）The second chapter mainly focuses on three kinds of heteropolyacids ionic liquids on MCF,the study of their synthetic structure and desulfurization effect.The synthesis of[BMIM]₃PMo₁₂O₄₀-MCF,[BMIM]₃PW₁₂O₄₀-MCF and[BMIM]₄Si W₁₂O₄₀-MCF realized the dual advantages of heteropolyacid ionic liquid and MCF.For four typical thiophene sulfides that are difficult to remove by hydrodesulfurization technology,three different heteropolyacids ionic liquids based MCF that are easy to synthesize exhibit efficient desulfurization ability.Among them,the catalyst of[BMIM]₃PMo₁₂O₄₀-MCF showed excellent desulfurization activity in the oxidative desulfurization system and the desulfurization rate of sulfide could reach 100%within 120 min.In addition,four sulfur compounds were completely removed.Due to the stable structure,the desulfurization efficiency of the catalyst still reaches 99.8%after being recycled for 6 times,which reflected the good recyclability and stability of the catalyst.At the same time,when the reaction system completes the desulfurization reaction,the catalyst can be recycled again only through simple separation treatment.（2）The third chapter mainly focuses on the synthesis of functionalized ionic liquid[BMIM]Fe Cl₄ modified MCF.Mesoporous foams silica modified with acidic ionic liquids was used as a Fenton-like catalyst,and hydrogen peroxide was used as an oxidant.It was used to construct an extraction catalytic oxidation desulfurization system for desulfurization.At the same time,the structure and desulfurization performance of catalyst were explored.MCF has its unique advantages of carrier.The functionalized ionic liquid[BMIM]Fe Cl₄ modified MCF is used as Fenton-like catalyst with Lewis acidity.The catalyst has both the excellent characteristics of ionic liquid and the catalytic performance of Fenton-like reagent.The synthesized catalyst has Lewis acidity,which interacts with the Lewis basic lone pair electrons contained in the sulfur atom in the sulfide.It can realize the synergistic effect of the extraction and catalytic processes,and further improve the removal efficiency of the sulfide.In addition,the synthesized solid Fenton-like catalyst is easy to be separated and recovered from the system.After six desulfurization experiments were completed,the desulfurization efficiency can still be maintained at 99.5%,achieving a deep desulfurization performance.（3）The fourth chapter mainly focuses on the preparation and synthesis of Lewis acidic ionic liquid[BMIM]Fe Cl₄ modified Janus,which are applied to the catalytic oxidative desulfurization of emulsion.The Lewis acidic ionic liquid[BMIM]Fe Cl₄ modified Janus has both the catalytic effect of the acidic ionic liquid and the amphiphilic dual effect of the emulsifier,realizing the bifunctional combination of the catalyst and the emulsifier.When deep desulfurization is achieved in the system,the catalyst can still maintain a high desulfurization efficiency after six desulfurization reactions are recycled.In the catalytic oxidative desulfurization system,the catalyst preparation conditions of[BMIM]Fe Cl₄modified Janus are mild and easy to synthesis.Centrifugal demulsification is easy to separate and it can be recycled for many times.It can be recycled without polluting the oil-water in two-phase system.The recovery and recycling of the green catalyst can be realized,showing the good stability.It is a practical catalytic material of application significance.