Smac Solid Acid Catalyst Preparation And Its Application In The The Coking Benzene Removal Of Thiophene

In recent years, with the people's awareness of environmental protection, the regulations of many countries in the world have become increasingly stringent for the sulfur content of various fuels. Our country has abundant coal resources, however, the content of sulfur compounds in coking benzene is relatively higher, so greatly limits the industrial use value of coking benzene. Therefore, removal of the thiophene sulfur in the coking benzene has great practical significance with a good approach. SO42-/MxOy solid superacid has some advantages such as high acid strength, no environment pollution and no corrosive to reactor, which could catalyze a lot of chemical reactions under mild conditions. SO42-/MxOy also has some disadvantages, such as small surface area, easy to deactivate and high cost. In this study, with activated clay as the carrier, which is cheap and easily to get, then sulfuric acid and metal oxide were used to modify and prepared several solid acid catalysts. The combination of activated clay and SO42-/MxOy to improve the catalyst surface area and catalytic activity, and solve the problem which easy to deactivate of catalyst, which were used in the catalytic alkylation desulfurization experiments of benzene coking, and obtained a higher acidity of solid acid catalysts and optimal reaction conditions.At the first part of this paper, the source, composition and application for crude benzene, the hazards of thiophene, the desulfurization technology at this stage and the research of the solid acid catalyst were summarized in detail. First, overview of coking benzene industry, which leads out the significance of coking benzene desulfurization were given. Then focuses on introduction of some common desulfurization methods used at this stage, such as catalytic hydrogenation desulfurization, adsorption desulfurization and alkylation desulfurization. Finally, the reseach of solid acid catalysts have also done a detailed introduction, especially doing a thorough research for several types of solid acid catalyst, such as Immobilization of liquid acid, natural clay and solid superacid, which direction of the study for the following experimental work in this paper.In the second part, we prepared SAC catalyst by using sulfuric acid to modify the activated clay with the impregnation, and applied it to remove thiophene in coking benzene. The best treatment conditions have been found by optimizing the factors which influence the catalytic perfor mance, such as acid concentration, acid treatment time and acid treatment temperature. Characterization of catalyst structure, the catalyst could removal thiophene in the coking benzene because of catalyst surface area and acid strength increase. Finally, the desulfurization reaction conditions were investigated, and obtained optimal reaction conditions. because of catalyst surface area and acid strength increase. Finally, the experiments investigated the desulfurization reaction conditions, and obtained optimal reaction conditions.In the third part we prepared SMAC solid acid catalysts by co-precipitation and applied them to remove thiophene in coking benzene. The best treatment conditions have been found by optimizing the factors which influence the catalytic performance, such as calcined temperature, calcined time, sulfuric acid concentration and loading dosage of metal oxides.The catalyst structure were characterized, and the catalyst show high catalytic properties in removal thiophene from the coking benzene because of increasing of catalyst surface area and the high acid strength. The desulfurization reaction conditions were also investigated the, and obtained the optimal reaction conditions. The results showed that the catalysts have high catalytic stability.In the fourth part, we prepared multi-component metal SMAC solid acid catalysts by co-precipitation. Comparison of the catalytic performance and catalytic stability with the single-component metal SMAC solid acid catalysts, the results showed that the multi-component metal SMAC solid acid have higher catalytic activity in thiophene removal from the coking benzene, and has more catalytic stability than the single-component metal SMAC solid acid.