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A series of Ni–P–Mo–W catalysts with different P2O5 contents in the support (0, 0.5, 1.0, 2.0, and 5.0 wt % P2O5, Mo : W = 1 : 1) were synthesized. Heteropoly acids H3PMo12O40·nH2O and H3PW12O40·nH2O, as well as nickel citrate, served as the active phase precursors. The sulfide phase morphology and surface were examined by the HRTEM and XPS methods. The catalytic properties of the samples in the dibenzothiophene hydrodesulfurization and naphthalene hydrogenation reactions were determined. The XPS examination showed that the ratios of different Mo species (Mo6+, MoSxOy, MoS2) for samples modified with 0.5 and 1.0 wt % P2O5 deviated significantly from those for the rest of the samples. Specifically, with an increase in the phosphorus content the proportion of the Mo6+ species decreased, while that of the MoSxOy species, increased, and for the W species, a linear increase in the WS2 proportion (from 15.3 to 35.0%) was revealed in parallel with the corresponding decrease in the W6+ species proportion (from 78.8 to 57.1%). The catalytic activity of the samples in the dibenzothiophene hydrogenolysis and naphthalene hydrogenation reactions exhibited an extremal dependence on the P2O5 content with a maximum observed at 0.5–1.0 wt % P2O5.

A set of NiMoW/P–Al2O3 catalysts with different P2O5 concentrations in the support (0, 0.5, 1.0, 2.0, 5.0 wt % P2O5; Mo : W = 1 : 2) has been synthesized using the following precursors: H3PMo12O40 and H3PW12O40 heteropoly acids for MoO3 and WO3, respectively, and nickel citrate for NiO. The morphology and surface composition of the sulfide phase of the samples have been studied by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy; the catalytic activity of the samples in the dibenzothiophene hydrodesulfurization and naphthalene hydrogenation reactions has been determined.

The group kinetics of reactions of organic sulfur compounds present in light cycle oil (LCO) in the hydrotreating process over a Co6–PMo12(S)/Al2O3 sulfide catalyst based on phosphomolybdic heteropoly acid as a function of hydrogen pressure (4, 5, and 6 MPa) at varying temperature (300–360°C in 20°C increments) and space velocities of 0.5, 1.0, and 3.0 h–1 has been studied. Total sulfur content in the feedstock and the hydrogenation products has been determined. The obtained data on the kinetics of hydrodesulfurization (HDS) reactions can be used to select optimum modes of the LCO hydrotreating process. Using the coefficient of determination and Fisher’s ratio test values, the adequacy of the pseudo-first-order and 1.5-order kinetic models and the Langmuir–Hinshelwood model has been determined. A kinetic model describing the hydrodesulfurization of LCO by hydrotreating in the presence of the Co6–PMo12(S)/Al2O3 catalyst has been selected, and the kinetic characteristics of the HDS of the compounds constituting LCO have been determined.

The effect from the P2O5 introduction on the activity of Co(Ni)-Mo/Al2O3 catalysts in hydrotreating reactions of petroleum feedstock was examined. As support served γ-Al2O3, prepared from aluminum hydroxide AlOOH powder TH-60 (Sasol), with the following textural characteristics: SBET = 205 m2/g, Vpore = 0.682 cm3/g, Reff = 48 A. In order to optimize the amount of the modifier the catalyst samples were modified with 0.5, 1.0, 2.0, and 5.0 wt % P2O5. The support was impregnated with an aqueous solution of H3PO4, and this was followed by drying and calcination. The modified supports were impregnated with an aqueous solution of the active phase precursors. The catalyst samples were examined by temperature-programmed desorption (TPD) of ammonia; they were sulfided before the tests. Their catalytic properties were studied in a micro-flow bench-scale reactor under hydrogen pressure in the hydrotreating reactions of mixtures of straight-run diesel fraction with light coker gas oil and of straight-run diesel fraction with catalytically cracked light gas oil. The activities of the catalysts were determined in hydrodesulfurization and hydrogenation reactions. After the test the catalysts were subjected to differential thermal analysis in combination with thermogravimetry (DTA-TGA). The relationship between the acidity of the oxide form of the catalysts and the catalyst activity in hydrogenation reactions was demonstrated. The influence of the amount of the modifier introduced on the catalyst activity and the content of coke on the catalysts after the test was elucidated.

A series of catalysts have been synthesized Ni–Mo–W/P-Al2O3 with different Mo: W ratios (a sample without W, Mo: W = 2: 1, Mo: W = 1: 1, Mo: W = 1: 2, and a sample without Мо) and a concentration of P2O5 in a support of 0.5 wt %. Heteropoly acids H3PMo12O40 · nH2O and H3PW12O40 · nH2O and nickel citrate were precursors of the active phase. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to study the surface of the sulfide phase of the samples. Their catalytic activity was estimated in the reactions of dibenzothiophene hydrodesulfurization and naphthalene hydrogenation. A catalyst with the ratio Mo: W = 1: 1 showed the highest activity, and was characterized by the maximum concentration of atomic groups Ni–Mo–W–S, Mo–S, and W–S.

Changes in the chemical composition of the vacuum gas oil in a mixture with heavy coker gas oil in the presence of industrial and laboratory NiMoW/P2O5–Al2O3 catalyst were studied. The support used was γ-Al2O3, prepared from AlOOH powder TH-60 (Sasol), with the following textural characteristics: SBET = 205 m2/g, Vpore = 0.682 cm3/g, Reff = 48 A. Alumina was modified with P2O5 by incipient wetness impregnation with a solution of phosphoric acid (reagent grade), followed by drying and calcination. The catalysts were prepared by incipient wetness impregnation with a combined solution of Mo, W, and Ni compounds. Before the catalytic test, the catalysts were subjected to sulfidation directly in the hydrotreating reactor of a laboratory setup in a stream of H2S/H2 = 70/30 vol %/vol % under 0.11 MPa pressure for 2 h at 500°C. The catalytic properties of the catalysts synthesized were examined under the following conditions: temperature of 360 and 390°C, hydrogen pressure of 5.0 MPa, liquid hourly space velocity of 1.0 h–1, volume ratio of hydrogen to feed of 1000: 1 nL/L, catalyst loading (0.50–0.25 mm fraction) 27 cm3. The reactor temperature was controlled accurately to within 1°C, pressure, to within 0.1 MPa, feed rate, to within 0.2 mL/h, and hydrogen flow, to within 0.2 L/h. During the process the contents of sulfur and polycyclic aromatic hydrocarbons, as well as the hydrocarbon-type content and carbon content of the feed and the hydrogenates, were determined. After the tests the catalysts were studied by differential thermal analysis in combination with thermogravimetry (DTA-TGA).

A series of NiMoW/P-Al2O3 catalysts with different Mo/W ratios (sample containing Mo only, Mo/W = 2: 1, Mo/W = 1: 1, Mo/W = 1: 2, and sample containing W only; P2O5 content of the support 2.0 wt %) were synthesized. The precursors of the active phase were the heteropoly acids H3PMo12O40∙nH2O and H3PW12O40∙nH2O, and also nickel citrate. The sulfide phase in the samples was studied by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy; the catalytic activity of the samples in dibenzothiophene hydrodesulfurization and naphthalene hydrogenation was determined. For the dibenzothiophene hydrogenolysis in the presence of quinoline and naphthalene (content in the model mixture, wt %: dibenzothiophene 0.3, naphthalene 1.5, and quinoline 0.5), kHDS for different samples is in the range 17.6–42.5 h–1 at 275°C and 24.6–45.9 h–1 at 300°C. For the naphthalene hydrogenation, kHYD varies from 0.79 to 1.89 h–1 at 275°C and from 0.91 to 3.78 h–1 at 300°C. The sample based on molybdenum showed the highest activity in hydrogenation and hydrodesulfurization.

The degree of hydrogenation of various classes of aromatic and olefin hydrocarbons in the cat cracking light gas oil hydrofining process in the presence of Al-Co-Mo and Al-Ni-W catalysts is studied. The Al-Ni-W catalyst exhibits much greater hydrogenation activity with respect to aromatic hydrocarbons than the Al-Co-Mo catalyst. However, the Al-Co-Mo catalyst exhibits much greater hydrogenation activity with respect to olefin hydrocarbons than the Al-Ni-W catalyst.

The influence of the introduction of V2O5 into NiMo/Al2O3 catalysts on their activity in hydrodesulfurization (HDS) and hydrogenation reactions of the components of petroleum fractions has been studied. The activity of the synthesized catalysts has been determined in the straight-run diesel and light coker gas oil hydrotreating processes in a flow-through unit under hydrogen pressure. The most active catalyst for HDS and hydrogenation of polycyclic aromatic hydrocarbons has been synthesized using VMo12 heteropoly compounds: the activity increases by 6–10 and 11–13 wt % in HDS and PAH hydrogenation, respectively, at different temperatures. It has been shown that the activity of the regenerated catalyst further impregnated with the vanadium compound in HDS and PAH hydrogenation increases by 2–5 rel. %, as compared to the regenerated catalyst.

The effect of the introduction of P2O5 into Ni–Mo/Al2O3 catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-Al2O3 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.

The dependence of the catalytic activity of nickel–molybdenum–tungsten sulfide catalysts on the Mo/W molar ratio is studied in order to develop an effective catalytic composition for the hydrorefining of petroleum. Threemetallic catalysts of Ni6-PMo n W12–n /Al2O3 composition, where n = 0–12 (Ni6-PMo n W12–n (S)/Al2O3 after sulfurizing), are synthesized. The morphology of the active-phase particles of sulfide samples is investigated using high-resolution transmission electron microscopy. The average length of NiMo(W)S phase layers, the average number of layers in a crystallite, the number of Mo(W) atoms in a layer, and the fraction of Mo(W) atoms in the rib and angular positions are calculated. The effect of the Mo/W molar ratio on the catalytic activity of the prepared samples is studied during the dibenzothiophene hydrogenolysis, hydrodesulfurization (HDS), and hydrogenation of olephins and aromatic compounds when hydrotreating diesel fractions and vacuum gas oil. A sample with molar ratio Mo: W = 1: 1 was found to be the one most active in the reactions of HDS and hydrogenation.

The effect of the introduction of ZnO into the NiMoW/Al2O3 hydrotreating catalyst on its activity in dibenzothiophene (DBT) hydrogenolysis has been studied. To select the optimal method for introducing the modifier, a series of samples has been prepared with ZnO added at different stages of the catalyst synthesis. Before the test, the catalysts were sulfided. The catalysts have been tested in the dibenzothiophene hydrogenolysis reaction was under hydrogen pressure using a continuous-flow microreactor. The interrelation of the active phase morphology, as well as the route of addition and amount of the added modifier with the catalytic activity of the samples has been revealed. Modification of the support by adding ZnO in an amount of 0.5 wt % increases the activity of the catalyst in DBT hydrogenolysis.

The results from 15 years of studies performed at the Samara State Technical University in the field of developing highly active sulfide catalysts for the hydrotreatment of straight-run and refractory low-grade oil fractions with the use of molybdenum and tungsten heteropoly compounds (HPCs) as precursors are presented. A wide range of HPCs with Anderson and Keggin structures is studied in the synthesis of sulfide catalysts. The order of activities in the hydrodesulfurization of sulfur compounds and the hydrogenation of unsaturated hydrocarbons are established for the heteroelements incorporated into HPCs. Catalytic activity—HPC heteroatom electronegativity correlations are revealed. Special attention is given to controlling the selectivity of catalysts with respect to parallel hydrogenation and hydrodesulfurization reactions. A wide variety of highly active sulfide catalysts for the hydrotreatment of diesel fuel, catalytic cracking gasoline, vacuum gas oil, and lube feedstocks is developed. The techniques for their synthesis and activation (sulfidation) are substantiated. The developments are patented and are close to being introduced at oil refineries whenever they are ready.

The structural-group composition and properties of the base oil samples obtained by solvent extraction technology and with the use of hydrofinishing of the solvent refined product have been studied. Sample 1 has been obtained via solvent refining and subsequent dewaxing, and samples 2 and 3 have been obtained according to a scheme comprising solvent refining and raffinate hydrofinishing over a NiMoW/ZnO-Al2O3 catalyst followed by dewaxing. The hydrotreating of the raffinate in the presence of the modified NiMoW/ZnO-Al2O3 catalyst can be conducted under mild conditions at 5.0 MPa.