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Thermal and catalytic pyrolysis of vacuum gas oil in a flow-type reactor were investigated. The main patterns in the yield of the targeted products of the process – ethylene, propylene and butylenes – are identified. The effect of the catalyst on change in the conditions of catalytic pyrolysis compared with thermal pyrolysis is described. A mathematical model of the process is proposed. [ABSTRACT FROM AUTHOR]

A hierarchical Beta zeolite has been successfully mass‐prepared hydrothermally and dynamically in a pilot‐scale autoclave by an economical and simple process with low‐cost raw materials. The characterization results indicated that the pilot‐scale hierarchical Beta zeolite has the same textural, structural, and acidic properties like the bench‐scale sample. Moreover, the catalyst composed of the pilot‐scale hierarchical H‐Beta zeolite showed higher activity and selectivity to the middle distillate than that containing microporous Beta zeolite in catalytic hydrocracking of vacuum gas oil (VGO) evaluated by an industrial pilot installation in running of 3000 h, due to the increased accessibility and the reduction of diffusion constraint of large molecules to acid sites in the Beta zeolite framework. [ABSTRACT FROM AUTHOR]

• Flow reactor (kg/day) data of NiMo/SiO 2 -Al 2 O 3 hydrocracking of vacuum gas oil and wax. • Competitive adsorption directionally explains lower oil conversion in presence of wax. • Competitive adsorption directionally explains higher S and N conversion with wax. • Bulk solubility effects explain magnitude of change in conversion caused by wax. The hydrocracking of vacuum gas oil (VGO) and a mixture of 90 wt% VGO and 10 wt% wax was investigated. The study provided insight into processing of naturally waxy petroleum, as well as refinery co-processing of Fischer–Tropsch products with petroleum. The investigation was performed using flow reactor system at kilogram per day scale. Hydrocracking was investigated over a sulfided NiMo/SiO 2 -Al 2 O 3 catalyst in the temperature range 330–410 °C at 9.5 MPa and LHSV of 1.3 h−1 with H 2 -to-feed ratio of 620 normal m3/m3. Atmospheric residue conversion of the VGO was 8–12% higher than conversion of VGO + wax at 330–380 °C, and 24% higher at 410 °C. Hydrodesulfurization conversion of the feed (3 wt% S) was less for VGO than for VGO + wax. Hydrodenitrogenation conversion of the feed (0.2 wt% N) was less for VGO than for VGO + wax. Directionally the observations could be explained in terms of competitive adsorption. However, the extent of the difference in atmospheric residue conversion was more than could be explained by competitive adsorption and VGO dilution by wax. It was postulated that changes in the bulk solubility characteristics of the liquid contributed to alter the relative concentration of species at the catalyst surface based on the change in the solubility parameter of the bulk liquid relative to the individual species. In this way it was possible to also account for the extent of the conversion difference observed during hydrocracking of VGO and VGO + wax at similar conditions. [ABSTRACT FROM AUTHOR]

Data are given on the cracking of vacuum gas oil with HY zeolite catalysts on aluminum pillared natural calcium montmorillonite under vigorous cracking conditions in laboratory reactors of different volumes with a fixed catalyst bed at 500-600°C. Increasing the cracking temperature and contact time of the vacuum gas oil with the catalyst was shown to increase the yield of the gas phase. The greatest gas yield was 42%. In this case, the gas contained C2 - C4 alkenes, including 28% propylene. We concluded that it should be possible to use aluminum pillared calcium montmorillonite as a component of a zeolite cracking catalyst for petrochemical processes. [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]

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]

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]

Development of models for industrial hydrocrackers has received a great amount of attention by the scientific community over the past decades. Two fundamentally different modelling approaches are compared in this paper: a continuous lumping model with three families (paraffins, naphthenes, and aromatics) and a single events microkinetic model. The aim is to demonstrate the differences in the capabilities of the two modelling frameworks. Both models are capable of simulating experimental data from hydrocracking of a pre-treated Vacuum Gas Oil in a pilot plant at industrial conditions. The continuous lumping model provides better results of the macroscopic effluent characteristics, such as yield structure and PNA (Paraffin, Naphthene, Aromatic) distribution in the middle distillate cut. It requires only the feed SIMDIS (Simulated Distillation) and PNA composition to be known. The single events model, on the other hand, provides information which is not available in a simple continuous lumping model. An analysis of the reaction kinetics of paraffins and mono-naphthenes is performed to demonstrate this aspect. The single events model is far more complex and computationally expensive than the continuous lumping model. In conclusion, the two approaches should be considered complementary rather than competitive. In conjunction, they can be used to balance the drawbacks of each individual modelling approach. [ABSTRACT FROM AUTHOR]

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 Ni-PMoW/AlO composition, where n = 0-12 (Ni-PMoW(S)/AlO 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. [ABSTRACT FROM AUTHOR]

A new CoNiMo/AlO deep vacuum gas oil hydrotreatment catalyst designed for the production of catalytic cracking feedstocks containing 200-500 ppm of sulfur is developed. The method for its preparation includes the following stages: the preparation of a support with specified textural, strength, and granulometric characteristics; the synthesis of bimetallic (Co-Mo and Ni-Mo) complex compounds in solution; and their deposition and drying. The new sample is compared to current domestic and imported industrial analogs according to their physicochemical (texture, morphology, active phase structure) and catalytic characteristics and analyzed. It is shown that the catalyst allows hydrotreatment at temperatures 5-20°C lower and target fraction yields 4-13% higher than all the reference samples. The high activity of the new catalyst is due to the formation of one-layer trimetallic Co(Ni)MoS phase particles at the stage of its sulfidation. The catalyst preparation technique is ready for industrial use (OOO Sintez, Barnaul, 1000 t/yr), and the principal technological regimes of the hydrotreatment of vacuum gas oil on the developed catalyst are determined. [ABSTRACT FROM AUTHOR]

Abstract: The main objective of this work is to develop a predictive model for predicting the product quality of vacuum gas oil (VGO) hydrocracking process. Experimental data were obtained using a pilot plant hydrocracking catalytic reactor loaded with the same catalyst type used in a local refinery. Two sets of experimental runs were conducted under various operating conditions. The first one consisted of 18 runs and was used for parameter estimation, while the second set consisted of 29 runs and was used for model validation. Distillation curves of the cracked products were obtained using the simulated distillation (SimDist) test. A distribution model based on probability density function was used to develop the predictive model. The distribution model presents the boiling point as a function of the distilled weight fraction. Model parameters were estimated and related to the specific gravity of the cracked product. Model validation results showed that the proposed model is capable of predicting the distillation curves of the hydrocracked products accurately, especially at high operating severity. Simplicity and accuracy of the developed model makes it suitable for online analysis, to estimate the conversion as well as the product distribution of hydrocracking units in refineries. [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]

In a two-stage hydrocracking process, two types of catalyst are used to remove undesirable contaminants (such as S, N, hydrogenation of aromatic compounds, etc.) and convert the heavy feedstock to lighter products. In the present work, individual set of experiments were conducted to obtain information regarding activity and selectivity with emphasis on the evaluation of kinetic parameters of first- and second-stage commercial catalysts used in hydrocracking process. The performance tests were conducted in a down-flow fixed-bed hydrocracking pilot plant using a single reactor. The hydrotreating type A catalyst and hydrocracking type B catalyst were used individually with typical Kuwaiti refinery feedstocks, namely, hydrotreated vacuum gas oil (HVGO) and unconverted residual oil (UCRO), respectively. The order of reaction in this study shows first-order kinetics for HDS and HDN over CAT-A, and first-order hydrocracking conversion over CAT-B. For CAT-A the activation energies were found for HDS and HDN reactions at 22 and 27.3 kcal/gmole, while for CAT-B activation energies were 27.4 kcal/gmole. [ABSTRACT FROM AUTHOR]

[Display omitted] • Influence of catalysts order and ratio in the bed loading was studied. • NiMo/Al 2 O 3 had the highest HDS and HDN activities of the model and real feed. • SRVGO should be treated firstly by NiMo and then by CoMo catalysts. • The best ratio of NiMo/Al 2 O 3 to CoMo/Al 2 O 3 and catalysts was 40/60 vol%. The influence of the order of catalysts and their ratio in the bed for FCC feedstock hydrotreatment was investigated. CoMo/Al 2 O 3 and NiMo/Al 2 O 3 catalysts were prepared in the laboratory and studied by nitrogen adsorption–desorption, XPS and HRTEM methods. The catalysts were tested in hydrotreatment of model feedstocks. It was found that NiMo/Al 2 O 3 catalyst had the highest activity in conversion of the model feedstock containing sulfur and nitrogen compounds. The best results were obtained for the feedstock firstly treated by NiMo/Al 2 O 3 and then by CoMo/Al 2 O 3. Catalysts were tested separately and together in hydrotreatment of SRVGO. The order of catalysts and their ratio were varied. The best combination included NiMo/Al 2 O 3 catalyst at the top of the reactor and CoMo/Al 2 O 3 at the bottom of the reactor in the ratio of 40/60 vol%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrasonic waves can improve the synthesis of 2D porous M-GO as HDS catalysts. • 2D MoS 2 -GO catalysts demonstrated the HDS reaction of VGO at facile condition operation. • DFT calculations were employed to reveal the detailed mechanism of the HDS process. In this study, a novel, simple, high yield, and scalable method is proposed to synthesize highly porous MoS 2 /graphene oxide (M−GO) nanocomposites by reacting the GO and co-exfoliation of bulky MoS 2 in the presence of polyvinyl pyrrolidone (PVP) under different condition of ultrasonication. Also, the effect of ultrasonic output power on the particle size distribution of metal cluster on the surface of nanocatalysts is studied. It is found that the use of the ultrasonication method can reduce the particle size and increase the specific surface area of M−GO nanocomposite catalysts which leads to HDS activity is increased. These nanocomposite catalysts are characterized by XRD, Raman spectroscopy, SEM, STEM, HR-TEM, AFM, XPS, ICP, BET surface, TPR and TPD techniques. The effects of physicochemical properties of the M−GO nanocomposites on the hydrodesulfurization (HDS) reactions of vacuum gas oil (VGO) has been also studied. Catalytic activities of MoS 2 -GO nanocomposite are investigated by different operating conditions. M9-GO nanocatalyst with high surface area (324 m2/g) and large pore size (110.3 Å), have the best catalytic performance (99.95%) compared with Co-Mo/γAl 2 O 3 (97.91%). Density functional theory (DFT) calculations were also used to elucidate the HDS mechanism over the M−GO catalyst. It is found that the GO substrate can stabilize MoS 2 layers through weak van der Waals interactions between carbon atoms of the GO and S atoms of MoS 2. At both Mo- and S-edges, the direct desulfurization (DDS) is found as the main reaction pathway for the hydrodesulfurization of DBT molecules. [ABSTRACT FROM AUTHOR]

• Influence of Si addition at AlOOH preparation stage in HDT catalysts was studied. • Positive effect of Si on HDS and HDN activities was defined. • Si decreases LAS of alumina support and catalysts. • Si changes particle morphology of boehmite during its synthesis. • Catalysts with Si/Al molar ratio 0.01 in support shows the highest HDT activity. Influence of Si addition at the stage of boehmite preparation on properties of NiMo/Al 2 O 3 catalysts for FCC feedstock pretreatment have been studied. The series of boehmites doped by PDMS at the stage of hydrothermal treatment was prepared. Si/Al molar ratio was 0, 0.01, 0.015 and 0.02. Boehmites were used for supports and catalysts preparation. Boehmites, supports and catalysts have been characterized by XRD, TGA, nitrogen adsorption-desorption, IR spectroscopy, UV–Vis, 29Si MAS NMR, HRTEM, EDX, XPS. Catalysts were tested in hydrotreating of FCC feedstock. It is shown that there are changes in morphology of boehmite particles and textural characteristics of aluminas. Introduction of Si to alumina induces formation of wider mesopores and blocks part of the Lewis acid sites of alumina. Testing of catalysts in hydrotreating of FCC feedstock shows that the catalyst with Si/Al ratio of 0.01 in boehmite has the best combination of hydrodesulfurization and hydrodenitrogenation activities. [ABSTRACT FROM AUTHOR]