Study On Application Of Novle Ionic Liquid/Heteropolyacid In Deep Desulfurization Of Gasoline

In this article, five types of desulfurization systems have been designed including (1) Ce-doped heteropoly acid ionic liquids catalyzed H2O2 oxidative desulfrization of model ethanol gasoline, (2) extraction-oxidation difunctional 18-amino heteropoly acid ionic liquids catalyzed H2O2 oxidative desulfurization of gasoline, (3) polyether-based 18-amino ionic liquids extracting desulfurization of gasoline, (4) self-assembly heteropoly acid catalyzed O2 oxidative desulfurization of gasoline, (5) non-catalytic cooxidation desulfurization of gasoline with O2 oxidant. These five systems have achieved excellent results of desulfurization.A series of Ce-doped heteropoly acid ionic liquids have been synthesized by using imidazole, propane sultone, n-butyl chloride, chloroacetate, cerous carbonate, phosphotungstic acid as raw materials. The structures of the ionic liquids are characterized by FT-IR and 1H NMR. The ionic liquids are used for catalyzing H2O2 oxidative desulfurization of model ethanol gasoline. The best catalyst is Ce0.66[DMIM]PW12O40-The optimum conditions are as follows:the amount of the catalyst 0.016 mmol,50μL of H2O2,1.0 mL of ethanol,10.0 mL of model oil, T=30℃ and t=10 min. Under the above conditions, the sulfur removel can reach 91.9%. The activity order of different sulfur compounds is DBT>4,6-DMDBT>ethyl sulfide>methyl phenyl sulfide>n-butanethiol>phenyl sulfide>BT>thiophen.A series of extraction-oxidation difunctional 18-amino heteropoly acid ionic liquids have been synthesized by using ethylene oxide, octadecylamine, n-butyl chloride, heteropolymolybdate as raw materials. The structures of the ionic liquids are characterized by FT-IR and 1H NMR. The ionic liquids are used for catalyzing H2O2 oxidative desulfurization. The effects of the degree of polymerization, ionic liquid dosage, H2O2 dosage, reaction time and temperature on the catalytic desulfurization are studied, and the recycling of the ionic liquid is investigated. The optimum conditions are as follows:18-amino heteropoly acid ionic liquids (n=108, C4),V(H2O2)=50μL, m(IL)=1.5 g,T=45℃ and t=20 min. Under the above conditions, the BT removel can reach 100%. After 8 reusing of the ionic liquids, the desulfurization still is higher than 85%.A series of polyether-based 18-amino ionic liquids have been synthesized by using octadecylamine, ethylene oxide, N-methyl imidazole, CuCl, NaBF4 and KPF6 as raw materials. The structures of the ionic liquids are characterized by FT-IR and 1H NMR. The ionic liquids have been applied for extracting desulfurization of model gasoline and real gasoline. The effects of the degree of polymerization, the amount of accessory ingredient, the amount of ionic liquid, extraction time, temperature, sulfur compounds on the desulfurization have been studied. The best ionic liquid extracting agent (n=60, C6H5CH2-, Cl-) is gotten. The optimum conditions for model gasoline are as follows:m(IL):m(oil)=3.5:1,7=30℃, and t=5 min. The corresponding desulfurization rate of BT is 84.7%. The optimum conditions for real gasoline (90#) are as follows:m(IL):m(oil)=3.5:1,7=30 ℃, and t=8 min. The corresponding desulfurization rate is 44.1%. The ionic liquid is saturated by sulfides after 10 times recycles, and the regenerated ionic liquid can be reused. After 64 times recycles, the loss of the catalyst is 15.3%, and the desulfurization still can reach 82.9%, which has a little decrease comparing with 84.7% gained by the new catalyst.63 kinds of self-assembled heteropoly acid solutions have been synthesized by using disodium hydrogen phosphate, sodium tungstate, sodium molybdate, sodium metavanadate, concentrated nitric acid as raw materials. The structures of self-assembled heteropoly acid solutions are characterized by FT-IR,1H NMR and ESI. These solutions have been used to catalyze O2 oxidation desulfurization of gasoline. The best catalyst is V:W=2:10. The effects of the amount of the catalyst, the amount of O2, reaction temperature and different sulfur compounds on sulfur removal have been studied. The optimum conditions are as follows:V(catalyst)=2 mL, P(O2)=2.0 MPa, reaction temperature 135℃, and reaction time 2 h. The desulfurization rate can reached 98.5%. The disappearance of the cyclic voltammogram peak for the 8th reused catalyst indicates the structural damage of the catalyst.By using non-catalytic cooxidation of alkane with O2 as oxidant, DBT in model fuels is removed. The effects of reaction temperature, oxygen pressure and reaction time on the sulfur removal are investigated. The optimum conditions are gotten through the single factor experiments and orthogonal experiments. The optimum conditions are as follows:reaction temperature 128℃, the pressure of O2 0.75 MPa and reaction time 8 h. Under the optimum conditions, the sulfur removal can reach 100%.The paper has successfully developed five high-efficient deep desulfurization systems. The deep removal of the stubborn sulfur compounds, the separation of the catalyst/extracting agent, and the recycling of the catalyst/extracting agent all can be achieved by these desulfurization systems. The paper has provided new science basis for the application of ionic liquid in deep desulfurization. It is of importance for the basic theory research and the practical application.