Model Fluid Catalytic Cracking Gasoline Research Articles

The effect of carrier in KCoMoS-supported catalysts for hydro-upgrading of model FCC gasoline

K-CoMo/Sup (where Sup = Al2O3, SiO2, TiO2 and ZrO2) catalysts were synthesized using H3PMo12O40, CoCO3, KOH and citric acid. The catalysts were characterized by temperature-programmed reduction (TPR), temperature-programmed desorption of NH3, X-ray photoelectron spectroscopy, transmission electron microscopy. Samples were tested in hydrotreating of model fluid catalytic cracking gasoline and in selective hydrogenation of 1,5-hexadiene and n-heptene-1. The type of used carrier significantly affected the morphology of active phase and catalytic properties. Active sites productivity of K-CoMo/Sup catalysts in hydrodesulfurization (HDS) and olefin hydrogenation (HYDO) reactions as well as HDS/HYDO selectivity correlated with active phase morphology excepting TiO2-supported sample. Productivity of active sites in reactions of selective hydrogenation of diolefin depended on maximum peak reduction obtained from TPR, which in turn was a function of acidity of using supports. The highest HDS/HYDO selectivity was obtained at catalyst which possessed the lowest selectivity towards partial hydrogenation of diolefine compared to complete hydrogenation.

Desulfurization of model FCC gasoline by extraction with ionic liquid and conventional extraction solvents

ABSTRACTTo compare the desulfurization performance of conventional extraction solvents and novel ionic liquid, desulfurization experiments by extraction were conducted on sulfolane, acetonitrile, N-formyl morpholine, and [BPy]BF4 using model Fluid Catalytic Cracking gasoline (thiophene and n-octane) as feedstock. Results showed that the desulfurization rate of ionic liquid was worse than conventional extraction solvents, but its yield of sweet gasoline was higher, which could reach to 90.36%. Among the four solvents, N-formyl morpholine had the best desulfurization performance, while sulfolane was the most stable extraction agent.

Amorphous silica-alumina – perspective supports for selective hydrotreating of FCC gasoline: Influence of Mg

CoMo/Al2O3-ASA catalysts with Mg were synthesized. Catalysts differed in the way of Mg addition: 1. Mg was added to ASA, 2. Mg was added to the kneading paste during the support preparation, 3. Mg was added before or after Co and Mo by the impregnation. Catalysts were characterized by the following techniques: low-temperature N2 adsorption, IR of CO and CO2 adsorption, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy. Synthesized catalysts were tested in hydrotreating of the model fluid catalytic cracking gasoline containing 250 ppm of sulfur from thiophene, 40 wt.% of toluene, 40 wt.% of heptane and 20 wt.% of n-hexene-1. It was found that the addition of Mg resulted in changes of physico-chemical properties of catalysts and their HDS and HYD activities. The way of Mg addition influenced the content of Lewis and Brønsted acid sites and morphology of sulfide active component. Mg increased HDS activity and decreased octane number loss. The catalysts with Mg in the kneading paste of the support and with Mg added after active metals showed the best combination of HDS activity and selectivity.

Comparable investigation of spillover and cobalt promoter effects in CoMoS/CoSx/SiO2 catalysts for selective hydrotreating of model FCC gasoline

Cox-Co2Mo10/SiO2 and Co2Mo10/Cox/SiO2 catalysts with various Co/Mo ratios and active species compositions are prepared using H6[Co2Mo10O38H4] heteropolyacid, CoCO3 and citric acid. Catalysts are characterized using the following techniques: low-temperature N2 adsorption, temperature-programmed reduction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic activities of the synthesized catalysts are examined in hydrotreating of model fluid catalytic cracking (FCC) gasoline that contains 1000ppm of sulphur from thiophene and 36wt.% of n-hexene-1. As the Co/Mo ratio increases, hydrodesulphurization (HDS) and hydrogenation (HYD) activities of the prepared catalysts significantly builds up. The changes of catalytic properties and specifically of the HDS/HYDO selectivity factor of the synthesized CoMo catalysts arise from two effects: an alteration of the promotion degree of CoMoS active phase particles and a hydrogen spillover from CoSx species to active sites. The developed silica-supported CoMo catalysts may be a prospect for selective HDS and hydro-upgrading of FCC gasoline.

Selective hydrodesulfurization of model fluid catalytic cracking gasoline over sulfided Al2O3-supported Anderson heteropolyoxomolybdate-based catalysts

XMo6/Al2O3 catalysts were synthesized using XMo6-heteropolycompounds with Anderson’s structure (where X = Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Al). The sulfided catalysts were characterized by N2 adsorption, temperature-programmed reduction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The catalysts were tested in hydrotreating of model FCC gasoline contained thiophene (1000 ppm of sulfur) and 1-hexene (36 wt%). The correlations between HDS/HYDO selectivity and characteristics of XMoS species depending on the nature of the heteroatom X in XMo6-heteropolycompound indicated the predominance of the electronic effect under the geometrical impact in the catalytic properties. It was found that to create a catalyst with high HDS/HYDO selectivity, reaching the mixed CoMoS active phase is the key requirement.

Relation between composition and morphology of K(Co)MoS active phase species and their performances in hydrotreating of model FCC gasoline

K-Mo/Al2O3 and K-CoMo/Al2O3 catalysts with various amount of potassium (up to 15wt. %) were synthesized using H3PMo12O40, CoCO3 and KOH. The catalysts were characterised by the following techniques: low-temperature N2 adsorption, Raman spectroscopy, temperature-programmed reduction, temperature-programmed desorption of NH3, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy. Synthesized catalysts were tested in hydrotreating of model fluid catalytic cracking gasoline containing 1000ppm of sulphur from thiophene and 36wt. % of n-hexene-1. It was found that potassium incorporation led to the strong changes in both physical-chemical characteristics and catalytic behaviour of sulphide catalysts. Using potassium favoured the growth of average slab length and sulphidation degree of metals with selective formation of CoMoS active phase. Addition of potassium also led to the partial poisoning of the active sites what resulted in decrease of catalyst activities compared with the reference Mo/Al2O3 and CoMo/Al2O3 samples. Olefin hydrogenation was more sensitive to potassium than thiophene hydrodesulphurization what resulted in the growth of the dependence of selectivity factor on potassium content in the catalysts. Obtained results allowed us to suppose that potassium partially inserts in sulphide slabs with changing the nature of active sites and probably with formation of new type of active “KCoMoS” sites.

Effects of composition and morphology of active phase of CoMo/Al2O3 catalysts prepared using Co2Mo10–heteropolyacid and chelating agents on their catalytic properties in HDS and HYD reactions

CoMo/Al2O3 catalysts were synthesised from the ammonium and Co salts of [CoMo6O24H6]3− and [Co2Mo10O38H4]6− anions as well as Co–chelate complexes with nitrilotriacetic, ethylenediaminetetraacetic, citric and tartaric acids. The catalysts were characterised using X-ray powder diffraction, Raman spectroscopy, N2 physisorption, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The catalysts were tested in the hydrotreating (HDT) of a mixture containing thiophene and n-hexene-1, the hydrodesulphurisation (HDS) of dibenzothiophene and 4,6-dimethyldibenzothiophene and the HDT of diesel. The type of chelating agent significantly affects the structure of the active phase and catalytic properties. The catalytic activity, selectivity and turnover frequency during the HDS and hydrogenation reactions depend on the number and location of CoMoS sites, as well as the shape of the active phase crystallites. New “structure–activity” relationships were established. These approaches yielded catalysts that demonstrated high efficiency towards the deep diesel HDT and selective HDS of a model fluid catalytic cracking gasoline.

Ionic Liquid‐Coated Nickel Phosphide Catalysts for Selective Hydrodesulfurization

AbstractNi2P/SiO2 catalysts were coated with the ionic liquid (IL) 1‐butyl‐3‐methylimidazolium bis[(trifluoromethyl)sulfonyl]amide with different coating thicknesses and their selective hydrodesulfurization performances were investigated using a model fluid catalytic cracking gasoline. The selective factor on the IL‐coated catalysts (IL‐Ni2P/SiO2) first increased and then decreased as the initial mass ratio of IL to Ni2P/SiO2 catalyst ranged from 0.02 to 0.18. A maximum selectivity factor of 16.7 was found at a mass ratio of 0.10 which corresponds to full monolayer coverage on the original Ni2P/SiO2 catalyst by the IL. In comparison, the selectivity factor was 6.7 for the Ni2P/SiO2 catalyst, indicating a significant selectivity improvement by the IL coating method.