Desulfurization Performance And Adsorption Mechanism Of HKUST-1 In The Presence Of Competitors

Ultra deep desulfurization of fuel oil is a worldwide urgent issue to be resolved. Hydrodesulfurization has limitations in ultra deep desulfurization of gasoline, resulting in reduction of the octane number. Adsorption desulfurization, as a kind of simple and easy to operate method for ultra deep desulfurization, has no effect on the quality of gasoline, and is therefore expected to become one of the best auxiliary methods of hydrodesulfurization.Metal-organic Framework Materials (MOFs) was a kind of new inorganic-organic hybrid porous materials. The potential application in adsorption desulfurization has aroused researchers’increasing attention. This dissertation focused on the desulfurization performance of HKUST-1 in the presence of cyclohexene and toluene in terms of both static and fixed bed adsorption, as well as the adsorption mechanism in terms of in situ-IR, Uv-Vis, Raman technologies and thermodynamics. Moreover, the adsorption desulfurization performance of MIL-101 and MOF-505 was also investigated as an exploratory study.HKUST-1 showed a good adsorption selectivity to thiophene removal in the presence of cyclohexene and toluene. The adsorption isotherms on HKUST-1 displayed that thiophene adsorption fitted Langmuir equation, while cyclohexene and toluene adsorption matched Freundlich equation. Different adsorption model implies different adsorption mechanism. Adsorption heat of thiophene onto HKUST-1 was figured out to be-37.31±2.04 kJ/mol, suggesting a physical adsorption mechanism. The maximum adsorption capacity of thiophene on HKUST-1 was calculated to be 0.860 mol S/g at 25℃. The FT-IR results showed that two forces, which were Cu2+-S interaction and hydrogen bonding, were involved between HKUST-1 and thiophene; while hydrogen bonding and Cu2+…C=C interaction between HKUST-1 and cyclohexene; and only hydrogen bonding interaction between HKUST-1 and toluene. The Cu2+-S interaction plays the dominant role in thiophene adsorption, which is also suggested by the reduced sulfur capacities of methyl-substitued thiophene derivatives at 2-,3-, and 2,5-positions. HKUST-1 displayed good regeneration performance.MIL-101 and MOF-505 showed poor adsorption desulfurization performance for thiophene and dibenzothiophene. We supposed that the residual organic ligands in the channel of MIL-101 is responsible for it’s limited desulfurization performance, while the low surface area of MOF-505 is related to the poor adsorption desulfurization.