| As the requirement of environmental standard requried sulfur content of gasoline to be lower and lower, producing ultra-low fuel oil has become an important development trend of the world. This work mainly involved the investigation of S Zorb reactive adsorption desulfurization process for thiophene removal. A series of Ni/ZnO adsorbents supported on oxide and composite oxide are prepared by coprecipitation method. The reactive adsorption desulfurization performance of the adsorbents are evaluated on the fixed-bed reactor. The preparation method, pretreatment conditions and reaction conditions are optimized through the experiments. Composite oxide supported Ni/ZnO-SA adsorbent has the best desulfurization performance in this study, which can maintain a high desulfurization activity and high sulfur capacity.The physical and chemical properties of the adsorbents are characterized by XRD, BET, NH3-TPD, H2-TPR, TEM, FTIR. The results of charaterization are also linked with the reactive adsorption desulfurization performance of the adsorbents. It was found that the desulfurization capacity of Ni/ZnO is enhanced greatly when supported on proper mixed oxide; Ni/ZnO supported on SiO2-Al2O3 exhibits much higher desulfurization efficiency and sulfur adsorption capacity than unsupported Ni/ZnO. The higher desulfurization activity and sulfur capacity of Al2O3 and SiO2 supported adsorbent with small particle size, high the surface area and pore volume promotes the active metal phase high dispersion and the transfer of sulfur to ZnO with lower mass transfer resistance. Al2O3 can weaken the interaction of active phases and SiO2. Therefore, these oxides play a structural promoting role to the support contribution and support interaction with the active metal geometry. The adsorption behavior and mechanism between the sulfur compunds and adsorbents are discussed, and the effect of olefin on reactive adsorption desulfurization performance of adsorbents was analyzed. |
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