| In recent years, the dramatic environmental impact of sulfur oxides contained in engine exhaust emissions has been widely recognized. As a result specifications regarding sulfur content in fuels are becoming more and more stringent. As a new benign organic solvent, Ionic liquids (ILs) can effectively extract aromatic sulfur compounds which are difficult to remove by traditional methods. Therefore, using ionic liquids to remove sulfur compound has become a new method with great potent. The development of applying the ionic liquids in desulfurization is promising since they have the advantages of mild reaction conditions and non pollution.A series of pyridinium-based ionic liquids with different cations and anions were prepared by low cost materials, characterized by MS, FT-IR, UV test. Physicochemical properties like melting point, viscosity, acidity, thermal stability of these ionic liquids were investigated. Influencing factors of various cations and anions on ionic liquids'properties were briefly analyzed. The results showed that all the ionic liquids could be used as excellent solvents.The Partition Coefficients of different sulfur contents between ionic liquids and oil phase were investigated. The effects on partition coefficients of sulfur contents under different experiment conditions were studied. The results indicated that [C12,6BPy] HSO4 had the excellent extraction performance with extraction yield 51.0% for thiophene and 66.5% for dibenzothiophene. Model oil was multitple extracted by ionic liquids and the desulfurization rate reached above 85% after extracted 4 times. As the oxidant, H2O2's application on oxidation desulfurization in ionic liuids was investigated. The results showed that [BPy] HSO4 had the excellent catalytic performance. Compared with H2O2 as sole oxidant, when H2O2- acetic acid as the oxidant system, highedesulfurization rate of model oil was obtained, more than 90% of sulfur contents were removed. The reaction kinetics of oxidation have been studied meanwhile, it showed that the kinetics of catalytic oxiditation is fist-order. The oxidation desulfurization with ionic liquids in gasoline was also researched, and 95% of sulfur contents were removed. Ti-containing molecular sieveTi-βand Ti-MCM-41 with different pore diameter were prepared in different ways. XRD, FT-IR,SEM and TEM,EDS and UV-Vis were used to characterize the properties of these Ti-containing molecular sieves. The results showed that Ti had been introduced in framework of molecular sieve successfully, Prepared Ti-MCM-41 has regular structure and good long range order.Ti-containing molecular sieves were applied to catalyze the oxidation desulfurization of fuel in ionic liquids at the presence of H2O2. The results showed that in the ionic liquids system, catalytic activity of molecular sieves kept at a high level on sulfur compounds with small molecule, meanwhile catalytic activity on sulfur compounds with large molecule was quite acceptable as well. It indicated that catalytic reaction took place on the surface of Ti-containing molecular sieves, regardless of the influence of steric hindrance. The order of catalytic activity of Ti-containing molecular sieve is Ti-MCM-41>Ti-β>TS-1.As the ionic liquids own the merits of multiformity and designability, functionalization br?nsted ionic liquids with functional group of hydroxy acid in fork chain of cation were synthesized. FT-IR,ESI-MS,TG test were used to characterize these ionic liquids.When the functionalization ionic liquids were applied in the study of catalyse desulfurization of fuel oil, the results indicated that peroxoic acid with higher catalytic activity was formed by hydroxy acid in fork chain of cation and H2O2. Peroxoic acid can oxidize sulfur compounds which extracted from oil phase more efficiently. Ionic liquids were not only the extractant but also the catalyst in this reaction system. Thus they avoided the use of volatile organic solvents such as formic acid, acetic acid and solid catalyst in traditional process. As a result, desulfurization rate was enhanced and the whole reaction process was much more green and clean.
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