Changlong Yin

Synthesis, characterization, and application of hydotalcites in hydrodesulfurization of FCC gasoline

Magnesium–aluminum, copper–aluminum, zinc–aluminum hydrotalcite(HT) compounds were synthesized using co-precipitation method. The effects of stirring rate, feeding rate of reactants, pH, calcination temperature on the properties of Mg–Al mixed oxides were investigated by using XRD, TG-DTA and BET techniques. The catalytic activity and selectivity of CoMo/γ-Al2O3, CoMo/γ-Al2O3+HT catalysts for hydrodesulfurization of FCC gasoline were examined in a high pressure microreactor. The results showed that the catalysts with mixed oxide obtained from hydrotalcite as support give lower levels of olefin hydrogenation than the catalyst with γ-Al2O3 as support, and lower octane number reduction and hydrodesulfurization yield, too. The hydrodesulfurization activity order was as follows: CoMo/γ-Al2O3>CoMo/γ-Al2O3+Mg–Al(HT)>CoMo/γ-Al2O3+Cu–Al(HT)>CoMo/γ-Al2O3+Zn–Al(HT), and the olefin hydrogenation activity and octane number reduction order were as follows: CoMo/γ-Al2O3+Zn–Al(HT)

SUPPORT AND CoPcTS EFFECTS ON THE CATALYTIC ACTIVITY AND PROPERTIES OF MOLYBDENUM SULFIDE CATALYSTS

The effects of the support and Cobalt tetrasulfophthalocyanine (CoPcTS) on the catalytic activity of CoMo and NiMo catalysts were investigated. The TiO2–Al2O3, SiO2–Al2O3, ZrO2–Al2O3 mixed oxide carriers were prepared by impregnating Al2O3 with an ethanol solution of tetrabutyl titanate, tetraethyl orthosilicate, zirconium oxychloride, respectively. BET measurements showed that no large decrease of surface area and average pore size for the mixed oxide carrier. TPR data revealed that support affects the reduction temp. of molybdenum oxide, the reduction temp. was in the following order, TiO2–Al2O3<Al2O3<ZrO2–Al2O3<SiO2–Al2O3. The catalytic activity measurements showed the activities for thiophene were: TiO2–Al2O3> Al2O3>ZrO2–Al2O3>SiO2–Al2O3. CoPcTS can increase the HDS and HYD catalytic activities when supported on CoMo/Al2O3, while on CoMo/TiO2–Al2O3 and NiMo/TiO2–Al2O3 decrease the HDS and HYD activities.

Selectively Hydrodesulfurization of FCC Naphtha over Monolayer Dispersion Catalysts

Abstract Metal oxides and salts can disperse spontaneously to the surface and pores of zeolite or alumina as atomically monolayer dispersion. In this paper a series of supported solid base catalysts were prepared by the method of monolayer dispersion, and the dispersion thresholds were determined by means of X-ray diffraction quantitative phase analysis. The fundamental functions of cobalt-molybdenum sulfide catalysts on monolayer dispersion catalysts were evaluated by hydrodesulfurization of FCC naphtha in a 100 mL high-pressure reactor unit. Experimental results indicated that the catalyst prepared by monolayer dispersion method in this article gives higher selectivity than the traditional hydrogenation catalyst and the oxide catalyst from hydrotalcite-like compounds. And the catalyst may show greater hydrodesulfurization activity and less olefin saturation under the moderate reaction conditions.

Transformation of Cycloparaffin over Zeolite-Supported Metal Catalyst for Improving the Octane Number of Gasoline

Abstract In order to improve the octane number of gasoline, Ni/HZSM-5 and NiMo/HZSM-5 catalysts were prepared by impregnation method, and their activities for hydrocracking, hydroisomerization, and aromatization were investigated by the transformation of cylcohexane. The experimental results show that the conversion of cyclohexane is affected greatly by the reaction temperature. The production of methyl-cyclopentane is the result of the hydroisomerization of cyclohexane. The olefin distribution reveals that the hydrocracking reaction of cyclohexane over acidic zeolite catalyst probably obeys the dimolecular mechanism and the C5 and C7 olefins come from the cracking of the dimer of cyclohexane. The activities of the presulfided Ni/HZSM-5 and NiMo/HZSM-5 catalyst for the transformation of cyclohexane were evaluated and the product selectivities for two presulfided catalysts are similar to those obtained over reduced Ni/HZSM-5 catalyst.

Effects of Modified Co-Mo Catalysts for FCC Gasoline HDS on Catalytic Activity

Abstract In this paper, a series of catalysts with HZSM-5/γ-Al2O3, HZSM-5/ TiO2-γ-Al2O3 as supports, bearing Co-Mo as active components, were prepared, and the catalysts were modified with alkaline earth and VIII, IB metal oxide. The catalysts were evaluated by hydrodesulfurization for QILU FCC gasoline. The experiment results showed that: (1) the RON (research octane number) of effluents rose with the increase of ZSM-5 mass percent in the support, but the HDS ration reduced; (2) the catalysts with ZSM-5/TiO2-Al2O3 as support had higher HDS ratio but lower RON of effluent; (3) the catalysts modified with metal oxide had higher RON of effluent, but lower HDS ratio. Compared with the stuff, and as to RON of effluent and hydrodesulfurization ratio for the modified catalysts, it had the following order: Ba-modified > Fe-modified > Cu-modified.