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A number of cracking catalyst samples containing Me–Mg–Al mixed oxides have been prepared. Cobalt, zinc, copper, and cerium were used as additional metals in the mixed oxide composition. When studying the cracking of a vacuum gas oil–sunflower oil mixture, catalysts containing Co–Mg–Al or Zn–Mg–Al mixed oxides were found to increase both the conversion rate of the mixed feedstock by 5.0 wt % compared to a sample containing the mixed oxide free of additional metal, and the gasoline yield by 1.6–3.0 wt %. It was discovered that the modification of mixed oxides with cobalt or zinc cations has no significant effect on the distribution of inorganic products, thereby indicating sustained catalytic activity during the decarboxylation reaction. The catalytic tests also demonstrated that catalyst samples containing mixed Mg–Al oxides with copper cations exhibited enhanced decarbonylation effect, as well as low conversion rates of the mixed feedstock and low gasoline yield, which is probably associated with the poisoning impact of copper oxide on Y zeolite. [ABSTRACT FROM AUTHOR]

The possibility of using of the catalytic system based on formic acid and a transition metal salt in the presence of hydrogen peroxide for desulfurization of nonhydrotreated vacuum gas oil has been explored. Conditions for effective oxidation of organic sulfur compounds and maximal extraction of oxidized compounds from the feedstock have been selected. It has been shown that the catalysts based on tungsten salts are the most effective those for oxidative desulfurization of heavy feedstock. Under optimum conditions, the degree of desulfurization of vacuum gas oil was 89%. [ABSTRACT FROM AUTHOR]

Nickel-tungsten sulfide catalysts synthesized by two methods—conventional supporting of active components and in situ synthesis in the reaction medium—have been characterized by a complex of physicochemical analysis methods. The catalysts have been compared with respect to their activity in the hydrocracking of vacuum gas oil (VGO) in a batch mode under conditions of varying temperature (380-400°C), reaction time (3-10 h), and zeolite (4-8 wt %) and NiW content (0.85-1.7 wt %). It has been shown that the in situ synthesized catalyst is superior in the hydrocracking and hydrodesulfurization of VGO owing to the accessibility of active catalyst sites. [ABSTRACT FROM AUTHOR]

The decomposition of nickel 2-ethylhexanoate by heating in a vacuum gas oil (VGO) medium at 355-365°С has been found to yield nickel and nickel sulfide nanoparticles. The size of the particles is 20-120 nm. The catalytic cracking of VGO in the presence of these nickel-containing particles provides a 70.15% yield of the distillate with a boiling point up to 220°C. The structural-group composition of the products of VGO cracking in the presence of nickel-based nanoscale catalysts has been studied using gas chromatography-mass spectrometry. The group composition of samples containing cracked products has been analyzed to cover eleven classes of organic compounds. The structural composition of the test samples has been considered with respect to eight groups of compounds, of which three include two to three classes of compounds. In the catalytic cracking of VGO, the concentration of alkanes increases by 3.11% and that of alkenes and alkylbenzenes decreases by 1.31 and 2.59%, respectively, as compared to their content in the products of VGO distillation without a catalyst. [ABSTRACT FROM AUTHOR]

An ordered mesoporous aluminosilicate of the Al-MCM-41 type has been studied as a component of additives for of petroleum feedstock cracking catalysts. The influence of the nature of the modifying material and its concentration on the activity of the additive has been investigated. It has been shown that the use of bimetallic additives on the basis of ordered mesoporous aluminosilicate makes it possible to reduce the sulfur content in liquid cracking products of vacuum gas oil by 37% more effectively in comparison with that for an additive-free industrial catalyst. [ABSTRACT FROM AUTHOR]

The activity of supported and in situ synthesized sulfide Ni–W catalysts based on a low-silicon zeolite Y (SiO2/Al2O3 = 5.2) in the hydrocracking of vacuum gas oil is studied. It is shown that the temperature and time of reaction affect the fractional composition and the sulfur content in conversion products. It is found that the phase of tungsten sulfide as well as the mixed Ni−W−S phase active in hydrogenation are formed on the catalyst surface. It is proposed that an increase in activity for the in situ formed catalyst may be explained by a high content of sulfide phases on the catalyst surface and accessibility of the zeolite pore system. [ABSTRACT FROM AUTHOR]

Alumina-based NiW catalysts have been prepared from 12-phosphotungstic heteropoly acid (PW12HPA), ammonium metatungstate (NH4)6H2[W12O40], and nickel hydroxide carbonate or nickel nitrate using citric acid (CA) or ethylenediaminetetraacetic acid (EDTA) as a chelating agent. The obtained samples have been studied by N2 adsorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy techniques. The catalysts obtained using the PW12HPA and CA have been characterized by the greatest dispersion of active-phase particles, and the use of EDTA has provided the maximum proportion of NiWS. The hydrodesulfurizing activity of catalysts in the hydrotreating of vacuum gas oil has been found to decrease in the following order: Ni-CAPW/Al2O3 > Ni-CAW/Al2O3 > Ni-EDTA-W/Al2O3 > Ni-W/Al2O3, which in general correlates with the particle size of the active phase and the concentration of promoted active sites. [ABSTRACT FROM AUTHOR]

The effect of the introduction of PO into Ni-Mo/AlO catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-AlO prepared from aluminum hydroxide AlOOH powder of the TH-100 brand (Sasol) has been used. The catalytic properties of the catalysts obtained have been examined in the hydrotreating of vacuum gas oil in a continuous-flow unit under hydrogen pressure. The amounts of sulfur and polycyclic aromatic hydrocarbons, the hydrocarbon group composition, and the carbon residue of the feedstock and the hydrotreating product have been determined. The catalysts after testing have been studied using differential thermal analysis in combination with thermogravimetry (DTA-TGA); the influence of the amount of the modifier on the catalytic activity and coking of the catalysts has been shown. [ABSTRACT FROM AUTHOR]

Three samples of γ-AlO with different textural characteristics have been synthesized from AlOOH powders (Sasol). Ni(Co)Mo/AlO catalysts have been prepared by single impregnation of the γ-AlO samples with solutions of active ingredients. The morphology of the active phase of the sulfided samples has been studied by high-resolution transmission electron microscopy. The catalytic activity has been measured with the use of vacuum gas oil (VGO) as a feedstock at temperatures of 360, 390 and 420°C. After catalytic activity measurements, the catalysts have been investigated by means of differential thermal and thermographic analysis (DTA-TGA). Textural characteristics of the catalysts in the oxide and sulfide forms have been determined, including those after the measurement of activity in VGO hydrotreating. The textural characteristics of the samples have been shown to correlate with the extent of the hydrogenation reactions of aromatic hydrocarbons and hydrodesulfurization. The highest hydrogenating and hydrodesulfurizing activity has been displayed by the sample on the support with the largest specific surface area and the smallest effective pore radius. [ABSTRACT FROM AUTHOR]

Oxidative desulfurization of a model mixture on the basis of vacuum gas oil and diesel fuel by hydrogen peroxide in the presence of formic acid has been studied. A technology of a two-phase system with a phase-transfer catalyst has been employed for the desulfurization. The optimum reaction time is 6 h and the hydrogen peroxide: sulfur molar ratio is 4: 1. As a result of successive triple oxidative desulfurization, 90% of total sulfur is removed from the model mixture. [ABSTRACT FROM AUTHOR]