Study On The Catalytic Performance Of Modified MCM-41in Full Range FCC Gasoline Upgrading

Ti and A1were introduced in silica MCM-41and a series of hydrodesulfurization catalysts were prepared from Ti-MCM-41and A1-MCM-41with different Si/Ti(Al) ratios modified with Co and Mo. The catalytic performance and optimum reaction conditions of Ti-MCM-41and Al-MCM-41were investigated using full range FCC gasoline as feed and we have reached the conclusions as follows:As hydrodesulfurization catalyst, mesoporous material MCM-41could reduce the saturation of olefin and its hydrodesulfurization activity was remarkably enhanced after framework Ti, anatase, and framework Al were introduced. The surface acidity of MCM-41was slightly increased after Ti species introduced and the pore volume was enlarged with the Ti content increased. The surface area of MCM-41decreased when Al introduced while its pore volume was enlarged more or less. However, the surface area of Al-MCM-41decreased more seriously when the content of Al increased, meanwhile the pore volume decreased.The framework Ti species inhibited the olefin saturation, while the anatase contributed to HDS activity. These two types of Ti species have synergistic effect and the catalyst had the best hydrodesulfurization selectivity when the Si/Ti mole ratio is15. However the most appropriate Si/Al mole ratio for Al-MCM-41is45which made it have a wonderful hydrodesulforization activity and selectivity because of the appropriate acidity and high dispersion of active phase on its surface.The optimum reaction conditions for CoMo/TM15catalyst were300℃,1.5MPa,2h-1under which the HDS, HDO and the maximal selectivity were72.4%,7.8%and64.6%respectively. Differently, the optimum reaction conditions for CoMo/AM45catalyst were300℃,1.0MPa,1h-1under which the HDS, HDO and the maximal selectivity were62.9%,3.5%and59.4%respectively.CoMo/TM15catalyst had better catalytic performance than CoMo/AM45under its optimum reaction conditions and this may rely on the better dispersion, appropriate reducibility and suitable polymerization of the active phases on it.