Study On AlCl₃Loaded Catalyst Of Alkylation Reaction Of Thiophene And Olefin In Coking Benzene

Coking benzene is the upstream product of benzene, the thiophene derivatives and olefins contained in it have a direct impact on its quality level. Alkylation method can convert thiophene and olefins into alkylthiophene by acid catalyst, then it can be more easily separated by distillation due to its higher boiling point than that of thiophene and benzene.In this thesis, AICl3/γ-Al2O3and AlCl3/silica gel catalysts were respectively prepared by closely pressurized and atmospheric loading methods, and then used to catalyze the alkylation reaction between thiophene and1-hexene in benzene. The evaluating results show that the catalysts prepared by the closely pressurized loading method present a higher catalytic activity than those by the atmospheric loading method. The ion chromatography, nitrogen adsorption, scanning electron microscope and X-ray diffraction techniques were used to characterize the composition and structure properties of catalysts. Compared with the atmospheric loading method, the closely pressurized loading method could effectively promote the active component amounts and improve the pore structure of the support during the preparing processes. In order to improved the surface acidity and pore structure of the support, the support were dipped by different concentration of HCl、H2SO4、NaOH and HF solution. These solutions possess different redox ability and acidity. The test results demonstrate that the catalysts’ activity can be increased remarkably in appropriate solution concentration. The reason is that the dipping treatment benefits the formation of catalytic active sites and free diffusion of reactant and product changed the surface hydroxyl and pore structure of support.In addition, the best catalyst’s reuse performance, the tolerance to water and the effect of olefin types in the system were investigated. The results show that the catalyst can possess a high activity after5times regeneration. And a certain amount of water didn’t harm the activity of it. When the molar ratio of styrene to thiophene in system is4:1, the thiophene conversion is highest.