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Co-Mo/γ-Al2O3 catalysts with different pore shapes were synthesized for the ex situ upgrading of extra heavy oils by hydrodesulfurization (HDS), hydrodemetallization (HDM), and hydrodeasphaltization (HDA). The catalysts were synthesized using aluminum oxides that were prepared by various methods. It was found that using the product obtained by the thermochemical activation of gibbsite leads to the formation of slit-shaped pores in aluminum oxide, while the application of the hydroxide deposition method by the precipitation of sodium aluminate and nitric acid gives cylindrical pores in aluminum oxide. Co-Mo catalysts synthesized using these two types of pores exhibit different catalytic activities. The catalyst synthesized on a carrier with cylindrical pores exhibited a higher catalytic activity in sulfur, heavy metals, and asphaltenes removal reactions that are synthesized on a carrier with slit-like pores. This is because the presence of cylindrical pores leads to a decrease in diffusion restrictions when removing large molecules of asphaltenes and sulfur-containing and metal-containing compounds.

In this paper, the Discrete Element Method of simulation was used to study the catalytic granule size effect on the efficiency of a bed reactor for the ethylbenzene dehydrogenation reaction. The model constructed for the laboratory experiment was made of catalyst granules of lengths 3, 6 and 9 mm, and diameters 2.8, 3, and 3.2 mm. A detailed evaluation of the catalyst total surface area and porosity effect was conducted owing to the analysis of particles size effect on the packing. Different results were observed for a wide feed gas mixture rate. Calculations performed allowed to deduce dependences of the reaction product concentration, the pressure drops, and the reactor productivity for all the particle sizes investigated.

Amorphous Al2O3 transforms into the pseudoboehmite and boehmite phases of AlO(OH) under hydrothermal conditions. Specific surface area, pore volume and the amount of acidic sites decrease upon complete conversion of amorphous Al2O3 into boehmite.

Alumina-supported palladium catalysts with acetate and acetylacetonate as precursors were synthesized. The properties of palladium in these systems treated in oxidizing and reducing atmospheres in a wide temperature range of 300–700 °C were investigated. According to the results of UV-vis DRS and TPR, the Pd(Ac)2/(δ + ϰ)-Al2O3 systems, oxidized at 300–700 °C, are characterized by the presence of large particles of PdO and Pd2+ in the structure of the aluminate phases. The subsequent reduction at 500 °C of the preoxidized Pd(Ac)2/(δ + ϰ)-Al2O3 systems according to the TEM results is accompanied by the formation of well crystallized palladium particles with an average diameter of 1.2 nm, which are characterized by the presence of the hydride form of hydrogen. The oxidation of Pd(Acac)2/(δ + ϰ)-Al2O3 in the temperature range 300–700 °C leads to the formation of small clusters of PdO and palladium–aluminate phases. When reducing, only cluster forms of palladium with a diameter of 1.3 nm are formed from them. It should be noted that palladium particles of catalysts have a close charge state and properties of active centers according to XPS and IRS of adsorbed CO. Therefore, the higher activity of the Pd(Ac)2/(δ + ϰ)-Al2O3 system is due to the presence of the hydride form of hydrogen. This fact leads to a high conversion of methylacetylene and propadiene, but a low selectivity of their conversion to propylene. An increase in the temperature of treatments to 600 °C is accompanied by an increase in the particle size of palladium. According to the results of IR spectroscopy of adsorbed carbon monoxide for the systems Pd(Ac)2/(δ + ϰ)-Al2O3 and Pd(Acac)2/(δ + ϰ)-Al2O3, the number of Pdδ+ centers and groups consisting of three atoms Pd0 is noted. This probably leads to the formation of fewer unsaturated hydrocarbon molecules firmly bound to the surface of the palladium particles, and less screening of the active surface of the palladium particles, with the formation of large areas of active sites where chemisorption of methylacetylene and propadiene is sterically possible. This in turn leads to an increase in the conversion of acetylene and diene hydrocarbons.

The effect of the acidic characteristics of an alumina support on the properties of formed palladium particles is studied to improve the activity of catalysts for the hydrogenation of unsaturated hydrocarbons of the pyrogasoline fraction. High catalytic activity is characteristic of highly dispersed palladium particles, but the surfaces of palladium particles are blocked by unsaturated hydrocarbons, due to their electron deficiency. In this work, palladium/alumina catalysts with supports of different acidities due to chemical modification with various reagents are studied via NH3 temperature-programed desorption, transmission electron microscopy, and X-ray photoelectron spectroscopy. The samples are subjected to catalytic tests in the butadiene-1,3 hydrogenation reaction under laboratory conditions. The catalysts on supports with acidic modifiers display low butadiene-1,3 conversion and higher selectivity toward butene-1, relative to an unmodified sample. The catalysts on the supports treated with basic additives displayed high butadiene-1,3 conversion while retaining their selectivities toward butene-1 and butane.

MCM-41 type mesoporous silica particles were obtained using a template method in an alkaline medium and cetyltrimethylammonium bromide as a matrix. The structural and adsorption characteristics of the mesoporous material were studied by dynamic light scattering, scanning electron microscopy, low-temperature adsorption—desorption of nitrogen, IR spectroscopy, and simultaneous thermal analysis. It was shown that the obtained mesoporous material possesses high porosity with the specific pore volume in excess of 1 cm3 g−1. It was established that the size of silica particles does not exceed 200 nm, which is a value acceptable for the penetration of drugs through cell membranes. The optimal compositions of aqueous dispersions of MCM-41 with minimal sedimentation processes were determined. A drug (indomethacin) was encapsulated into the silica pores using the precipitation method at various temperatures (40 and 60 °C), the quantitative parameters of loading efficiency were calculated. The infl uence of temperature on the encapsulation ability was demonstrated.

Using a mathematical model that describes the process of methylbutene dehydrogenation to isoprene, a comparative analysis of energy efficiency is performed for two upgrading variants: (1) a system of two serially arranged axial fixed-bed reactors and (2) an adiabatic fixed-bed reactor. A mathematical analysis is performed to determine the dependence of yield Y and selectivity S on quantity Q of thermal energy supplied by means of steam in each case. For the two-reactor system, the best performance characteristics (Y = 53.1% and S = 82.9%) are attained at Q = 9.0 MJ/kg and contact time t = 0.8 s. However, the best performance characteristics in the radial reactor (Y = 42.0% and S = 86.1%) are observed at Q = 7.8 MJ/kg and t = 0.8 s. It follows that the thermal energy required for the methylbutenes dehydrogenation reaction in the radial reactor is 13.0% lower than for the axial reactors.

Studies of the influence of acidity of alumina supports on properties of supported palladium particles were aimed at improving the activity of catalysts for hydrogenation of unsaturated hydrocarbons of pyrolysis gasoline fraction. High-disperse palladium particles demonstrate the high catalytic activity but their electron deficiency make them suffering from blocking with unsaturated hydrocarbons. NH3 TPR, TEM and XPS techniques were used for studying aluminopalladium catalysts; different acidities of the catalyst supports resulted from their chemical modification with various agents. The catalysts were tested for lab-scale hydrogenation of butadiene-1,3. Against the non-modified samples, the catalysts supported on modified alumina provided a lower conversion of butadiene-1,3 but a higher selectivity to butene-1. A higher conversion of butadiene-1,3 at the preserved selectivity to butene-1 and butane was observed in the presence of the catalyst supported on base-modified alumina.

The transformation of alumina-supported palladium salts during isothermal treatment in a reducing atmosphere has been studied to determine the optimum reduction temperature for the Pd/Al2O3 catalyst. It has been found that the interaction of palladium acetylacetonate with alumina surface sites is stronger than the interaction of the acetate complex. Owing to this factor, the diameter of the resulting active-ingredient particles is smaller in the case of the former precursor in the entire temperature range of reductive treatments. The optimum reduction temperature for the supported palladium salts is 500°С; this temperature provides the formation of palladium particles characterized by the maximum conversion of methylacetylene and propadiene at a high selectivity for conversion to propylene. The systems activated at temperatures of up to 400°C exhibit low activity in the hydrogenation of methylacetylene and propadiene; this behavior is attributed to an incomplete reduction of palladium from Pd salts to form oxidized and coordinatively unsaturated species of the active ingredient.

Novel nanocomposite system based on mesoporous silica nanoparticles (MSNs) noncovalently modified with hexadecyltriphenylphosphonium bromide (HTPPB) has been prepared, thoroughly characterized and used for encapsulation of model cargo Rhodamine B (RhB). The high encapsulation efficacy of this dye by HTPPB-modified mesoporous particles was demonstrated by spectrophotometry and thermography techniques. The bioavailability of MSN@HTPPB was testified. Cytotoxicity assay revealed that a marked suppression of M−HeLa cancer cells (epithelioid carcinoma of the cervix) occurs at concentration of 0.06 μg/mL, while the higher viability of Chang liver normal cell line was preserved in the concentration range of 0.98–0.06 μg/mL. Hemolysis assay demonstrated that only 2% of red blood cells are destructed at ~ 30 μg/mL concentration. This allows us to select the most harmless compositions based on MSN@HTPPB with minimal side effects toward normal cells and recommend them for the development of antitumor formulations. Fluorescence microscopy technique testified satisfactory penetration of HTPPB-modified carriers into M−HeLa cells. Importantly, modification of the MSN with HTPPB is shown to promote efficient delivery to mitochondria. To the best of our knowledge, it is one of the first successful examples of noncovalent surface modification of the MSNs with lipophilic phosphonium cation that improves targeted delivery of loads to mitochondria.

Highly porous cellular material (&alpha, Al2O3-HPCM) support was synthesized by the template method. Highly porous support was used for the synthesis of the catalyst. A thin secondary layer with 25&ndash, 30 &mu, thick &gamma, Al2O3 and zeolite Y was applied on the &alpha, Al2O3-HPCM surface ((&gamma, Al2O3 (85%)-zeolite Y (15%))/&alpha, Al2O3-HPCM). The catalyst based on the highly porous support was tested in a process of decreasing oil viscosity. The catalyst in the form of cylindrical granules and a thermal process of decreasing oil viscosity without the catalyst were used as the basis for comparison. &alpha, Al2O3-HPCM in the catalyst provides low-quantity pores (d &lt, 10 nm) and a quantity of general acid centers compared with the granular catalyst. On the other hand, it shows a more significant oil viscosity decrease (from 2500 to 41 cPs) and a low rate of gas generation (137 mL/h) for the catalyst with highly porous support. A high oil fraction was observed in the presence of the (&gamma, Al2O3-zeolite Y)/&alpha, Al2O3-HPCM compared to the granular catalyst. The presence of large transport cells (pores) 1500&ndash, 2000 &mu, for the catalyst based on highly porous support allowed a work period four times longer than that of experiment only with temperature without catalysts.

The coarse agglomerates of gibbsite (γ-Al(OH)3) are grateful starting materials for preparation aluminum oxides and hydroxides as boehmite and γ-Al2O3, which are extensively used as a catalysts and catalyst support for the petrochemical industry. By preparing the boehmite particles from the gibbsite and product of the heat gibbsite, we demonstrate the influence of different treatments to a morphology and particle size of the formed boehmite (γ-AlOOH). It is been established for the first time that the flaky-shaped 2D γ-AlOOH particles are formed within the coarse agglomerates producing a laminated packaging film lozenge-shaped crystals which results in a 0.1 cm3/g pore volume and 29 m2/g specific surface area. The obtained data have a high industrial importance in the area of producing materials based on the coarse boehmite agglomerates with different properties.

A mathematical model of the process of dehydrogenation of methylbutenes to isoprene was used for comparative analysis of energetic efficiency of two versions of modernization: (1) a system of consecutively connected two axial reactors with a fixed catalyst beds, and (2) adiabatic radial reactor with fixed catalyst bed. The purpose was to determine the dependence of yield (Y) and selectivity (S) to the target product on the heat energyQsupplied with vapor. In the two-reactor system, the best parameters (Y= 53.1 % andS= 82.9 %) were achieved atQ= 9.0 MJ/kg and contact time t = 0.8 s. At the same time, in the radial reactor the best performance (Y= 42.0 % andS= 86.1 %) was observed atQ= 7.8 MJ/kg andt= 0.8 s. Hence, the radial reactor consumes less heat energy (by 13.0 %) than the radial reactor for methylbutene dehydrogenation.

A numerical study of the fluidized bed industrial reactor in the presence of various internal elements is carried out by CFD methods A simple reactor heating efficiency function of chemical reaction with heat absorption is considered. The main emphasis is placed on the circulation flows of the catalyst particles and heating of the reactor. The analysis of the impact of various design elements on the heating efficiency of the reactor is carried out. Particular attention is paid to the possibility of baffles applying, which allows redirecting the flow. This effect may have an especially important value when the rapid heating of the reactor is required for temperature dependent reactions. The influence of heated catalyst feeder design on the efficiency of whole reactor heating is educed. The influence of the fractional composition of the catalyst, namely the presence of fine particles, on the reactor heating efficiency for different reactor design features is also studied. The results are carried out for a specific reactor example, but contribute to the overall branch of fluidized bed engineering.

For the development of a composite of nickel highly porous permeable cellular material with an applied secondary layer of alumina, transformation of the surface of the highly porous permeable cellular material is investigated at the stages of electrochemical synthesis and stages of alumina application on its surface. Etching of foamed-polyurethane bondings with 20% potassium hydroxide solution is accompanied by destruction of their surface and the formation of defective areas in the form of hillocks, hollows, and other imperfections acting as tin-hydroxide crystallization nuclei. Application of tin chloride with its subsequent hydrolysis leads to the formation of hemispherical tin-hydroxide grains with a mean size of about 80 nm uniformly distributed over the surface. The optimum values of temperature (50°C), solution pH (9–10), and electroless-nickel-plating duration (20–30 min), providing the formation of a conductive sublayer of chemically reduced nickel, are established. Nickel electroplating for 30 to 35 h at a current density of 0.1 A/dm2 yields high uniformity of a metal coating of foamed-polyurethane bondings across the thickness both in the bulk and at the outer periphery of a sample of 30 μm. A composite of nickel highly porous permeable cellular material with an applied alumina secondary layer is synthesized. The latter shows a high degree of uniformity and uniform thickness over the whole surface of bondings of the obtained composite.

We report a study of the phase transformation of gibbsite-boehmite under hydrothermal treatment in aqueous suspension and under the “dry steam” conditions at T = 180–210 °C and P = 1.0–1.9 MPa for 30–540 min. It is the first time that the closed mesopores formed during the splicing of large crystals in which water is encapsulated in an amount of up to 1.8% of the masses are found in boehmite. The spread of closed mesopores by the diameters depends on the conditions of hydrothermal treatment: in the aqueous suspension the mesopores are of the diameters less than 4 nm, under conditions of “dry steam”—in the range of 4–6 nm and ~ 10–200 nm. With those closed mesopores, it possible to use boehmite in various fields of chemistry and technology for the encapsulation and transport of solutions containing the active components and connections.

Hydrothermal modification of the alumina catalyst of n-butenes skeletal isomerization was investigated. It is shown that during the hydrothermal treatment of γ-Al2O3 and subsequent calcination its activity in skeletal isomerization of n-butenes first increases, and then it decreases with a rise of the hydrothermal treatment duration. This behavior is due to a similar change in the content of the strong Lewis acid sites of alumina, which are the active centers of reaction and they can be identified by IR-spectroscopy of the adsorbed pyridine and EPR-spectroscopy of the adsorbed anthraquinone. We report the mechanism of new Lewis acid sites formation at the γ-Al2O3 hydrothermal treatment containing X-ray amorphous component.

Influence exerted by acid-base modifiers of aluminum hydroxide on the texture and acid characteristics of the aluminum oxide support was studied. The effect of the modified aluminum oxides on the charge state of the active component of aluminum-palladium catalysts was determined. It was found that catalysts based on a support with high concentration of strong acid centers are characterized by low conversion of butadiene-1,3 due to the firm chemisorption of the diene on electron-deficient palladium particles. Their formation is due to the strong metal-support interaction. By contrast, catalysts synthesized with supports having a small number of acid centers provide a high conversion of butadiene-1,3.

The demand for C3-C5 olefins is constantly growing, that is why it is important to improve the performance of catalysts for dehydrogenation of light alkanes. The study regards the influence of the supports porous system, the contribution of α-Cr2O3 particles to the state of the active phase and the catalytic performance of the chromia-alumina catalysts in the isobutane dehydrogenation reaction. The catalysts were synthesized by impregnating the support with chromic acid. The supports and the catalysts were studied by the following techniques: low-temperature nitrogen adsorption, temperature-programmed desorption and reduction; UV-Vis- and Raman-spectroscopy, X-ray phase and X-ray fluorescence analyses. It was found that crystals of α-Cr2O3 are formed on a support with 56 m2/g specific surface area and 7.1% (m/m) chromium content, that contributes to stabilization of the particles of highly active phases of amorphous Cr2O3 and polychromates and catalytic performance. Meanwhile, no α-Cr2O3 particles are formed on a support with a 103 m2/g specific surface area and 7.4% (m/m) chromium content. Therefore, in the course of 54 regeneration reactions cycles, the rates of isobutylene formation and isobutylene selectivity are significantly reduced due to agglomeration of amorphous Cr2O3 particles, formation of di-, tri- chromates, and migration of part of chromium into the support structure.

It was shown for the first time that amorphous phase in an alumina support promotes the formation of palladium particles in a wide size range. This catalyst has a low selectivity to butenes in the 1,3-butadiene hydrogenation. It was suggested that surface palladium aluminates contribute to an increase in butene selectivity up to 99.5% at a hydrogenation temperature of not more than 65 °C. At higher reaction temperatures, the catalyst based on phase-homogeneous γ-Al2O3 has the highest activity and butene selectivity. This catalyst was obtained by the traditional impregnation method and contains highly dispersed palladium particles with a sufficiently high electron density. It was shown that the formation of hydride forms on palladium particles with a size of less than 1 nm was detected by temperature-programmed reduction with hydrogen.

Results from pilot tests of microspherical aluminochromium KDI-M catalyst mixed with IM-2201 in a large-scale unit (Nizhnekamskneftekhim) for iso-butane dehydrogenation are discussed. Compared to KDI catalyst, its modified analogue KDI-M is more active and selective; the optimized grain-size composition and mechanical strength ensures higher yields of iso-butylene and longer nonstop operation (up to 400 days) of the reactor unit.

Pilot tests of technology for the dehydration of methylbutenes to isoprene are performed in a tworeactor system with an additional supply of an overheated gas into the interreactor space. The tests are performed on a pilot plant with two adiabatic reactors. The total volume of the catalyst charge is 60 dm3, the temperatures are 565–620°С, the contact time is 0.18–0.25 s, the raw material is diluted with steam in a weight ratio of С5Н10: Н2О = 1.0: (6.0–30.0), and the excess pressure is 0.6–0.7 kgf/cm2. The dependence of the isoprene concentration in the contact gas on the heat energy supplied by the raw material and steam is determined under conventional conditions of the process and in a pseudo-isothermal mode via an additional supply of overheated gas into the interreactor space. It is shown that the isoprene yield is increased by 10–12% by using the upgraded mode. The conditions for conducting the industrial process are determined based on the obtained results. After upgrading the design, tests are performed at the synthetic rubber factory of PAO Nizhnekamskneftekhim on a plant for the dehydrogenation of methylbutenes in the reactor with a doublelayer catalyst bed (nine tons per layer). The patterns established during the pilot tests generally prove to be true, but the selectivity of the process is reduced due to a number of design flaws. Corrective measures are outlined. Comparison of the experimental results and the calculated values confirm the accuracy of the mathematical model.

The contribution of the amorphous phase in aluminum hydroxide and alumina to their properties was investigated in this work. It was shown that the amorphous phase in aluminum hydroxide is stabilized by alumoxanes, and it is a source of a finely porous component and capable of increasing the surface area by ~78%. In γ-Al2O3, amorphous alumina raises the surface area and the acidity. It was established that the method of chemical modification does not change the phase inhomogeneity but allows adjusting the acid properties while maintaining the high specific surface area. It was shown that the amorphous phase is more reactive when processing phase-inhomogeneous aluminum hydroxide with acetic acid. Crystallization of amorphous alumina as a result of high-temperature treatment of phase-inhomogeneous aluminum hydroxide is accompanied by significant decrease in specific surface area and acidity.

In this work, we carried out a numerical simulation of an industrial reactor of a radial type with a fixed catalyst bed for the process of ethylbenzene to styrene dehydrogenation. We solved the problem in the approximation of two-dimensional axial symmetry. The parameters of the chemically reacting gas mixture movement in the catalyst bed are considered. The reactor zones which have a negative impact on the reaction efficiency have been determined.

Amorphous aluminum compounds are formed during the synthesis of the &gamma, Al2O3 catalyst precursor. Amorphous compounds influence on the alumina catalyst variously due to different physicochemical properties, which depend on the method of their preparation. In this research, the comparative analysis of physicochemical properties of amorphous aluminum compounds that were obtained by the precipitation method, the thermal decomposition of aluminum nitrate, and alcoxide hydrolysis product were studied. It is the first time that a new method for calculating of quantitative phase composition of amorphous aluminum compounds using the X-ray powder diffraction, thermogravimetric and differential scanning calorimetry analysis, mass-spectrometry, and CHN-analysis was described. Properties of obtaining samples were studied using scanning electron microscopy, low-temperature nitrogen adsorption, and temperature programmed desorption of ammonium analyses. The methods of precipitation and thermal decomposition of aluminum nitrate allows for obtaining non-porous samples consisting of a mixture of amorphous phases (hydroxide and basic salt) that contain the metals impurities and have low acidity of the oxides obtained from them. The highly porous amorphous alumina formed by the thermal decomposition of the alcoxide hydrolysis product with the least amount of impurities and a high acidity of the surface was observed.

Mathematical modeling is performed for the operation of two units of industrial chemical fluidized-bed reactors with different gas feedstock injection devices, i.e, three toroidal rings with nozzles in unit 1 and a false bottom with nozzles distributed over it in unit 2. Efficiency is analyzed (using the target product (iso-butylene) yield) for the operation of the two units over 4 months under industrial conditions and revealed the higher efficiency of unit 2. To dedetrmine the reasons for different product yields in the two units, a numerical solution is found by mathematical modeling to obtain characteristic pictures of catalyst particle concentrations and temperature fields in these units. It is concluded that unit 2 is characterized by a more uniform and dense distribution of the catalyst along with more uniform heating of the reactor. Pictures of the principal catalyst circulation flows are plotted to explain the considerable difference between the catalyst concentrations and gas temperature fields. Based on the numerical solution, the operational efficiency of the two units is subjected to comparative analysis, which showed good agreement with the results from an analysis of industrial reactors. The approach used in this work could be used in designing new units and optimizing existing units.

The mathematical modelling of conventional metylbutene dehydrogenation technology (performed in an adiabatic reactor) and of three versions of this process conducted in a pseudo-isothermal mode is performed to select a variant of modernization that is optimal in terms of energy efficiency. These variants are (1) a single-reactor design with a fractional supply of steam to the upper and middle zones of the catalyst bed; (2) a design with two reactors in series and intermediate heating of the contact gas in an interstage superheater; and (3) a design with two reactors in series and the adding of an overheated gas into the interreactor space. It is shown that each of the new designs can significantly increase the effectiveness of the process, compared to the conventional technology. A comparative analysis is performed of the dependences of the selectivity and yield of isoprene formation on the amount of heat energy Q supplied in the experimental designs. It is concluded that at long times of contact, the greatest increase in the isoprene yield (5.5%) and selectivity (5.6%) is obtained with design (2), especially when Q > 8.5 × 106 J/kg.

The cerium recovery in the oxalate form from spent iron–potassium catalyst for dehydrogenation of isoamylenes into isoprene was studied. The optimum conditions allowing preparation of the pure product with high degree of recovery were found. It was proved by X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, and X-ray fluorescence analysis that the product obtained by the precipitation was cerium oxalate decahydrate containing no less than 98 wt % main substance.

Results of a study of the recovery of cerium dioxide from a spent iron-potassium catalyst for dehydrogenation of isoamylenes to isoprene are presented. The optimal conditions are found in which pure cerium dioxide can be obtained with large degree of recovery.

Method is found and substantiated for recovery of molybdenum from a spent iron-potassium catalyst for dehydrogenation of isoamylenes to isoprene. The effect of various factors (nature and concentration of the extracting agent, temperature and duration of the extraction process, and ratio between the liquid and solid phases) on the selectivity of recovery and the yield of molybdenum was studied. It is shown that molybdenum can be recycled in manufacture of iron-potassium catalysts for dehydrogenation of isoamylenes to isoprene.

A mathematical model describing the destruction of catalyst particles during operation in an industrial fluidized-bed reactor with allowance for the crushing and abrasion of particles is proposed. Differences between the mechanical properties of IM-2201 and KDI catalysts used in the dehydrogenation of iso-butane to iso-butylene at PAO Nizhnekamskneftekhim are established. Using KDI catalyst with modification of the cyclone group and retention of the equilibrium distribution of particles according to size in a reactor is shown to provide a more than a 2.5-fold reduction in catalyst consumption.

The presence of χ-Al2O3 resulting from thermal decomposition gibbsite as part of alumina catalysts is unfavorable because of its acid characteristics. One of the available techniques of χ-Al2O3 removal is crystallization under hydrothermal conditions into boehmite, which is a main precursor of active γ-Al2O3. The influence of products of the hydrothermal treatment of χ-Al2O3 obtaining in result of thermal decomposition gibbsite under T = 150–200 °C, P = 0.5–1.5 MPa and pH = 4.0–9.2 were studied. The hydrothermal treatment products in these conditions are gibbsite and boehmite phases which are formed coincidently by parallel ways. In the alkaline medium at pH = 8.0–9.2 three-dimensional parallelepiped boehmite crystals with the edge length > 200 nm are formed, at pH = 4.0 two-dimensional rhombic-shaped plates with thickness 20–100 nm and with the edge length ~ 80–500 nm are formed. Crystallization of coarse boehmite particles promotes the formation of large and closed mesoporous.

The effect of the morphological, textural, and acid characteristics of a support prepared from a composite of alumina and a nickel-containing highly porous permeable cellular material (HPCM) on the electronic and geometric properties of supported palladium particles and their activity in the selective hydrogenation of acetylene is studied. It is found that a δ-Al2O3/Ni-HPCM support ensures the formation of a more uniform charge state distribution of the active component in comparison with the conventional catalysts supported on pure δ-Al2O3, i.e., palladium particles with surface atoms that have a higher electron density on the valence orbitals. This state of the active component is responsible for the high selectivity of the hydrogenation of acetylene to ethylene in the ethane-ethylene fraction when using a Pd/δ-Al2O3/Ni-HPCM catalyst; this selectivity is 78.3%, which is 35.7% higher than that of the process using a catalyst based on conventional δ-Al2O3.

In this work, we performed mathematical modeling of internal elements for mixing the reaction flows. The reactor of the dehydrogenation of ethylbenzene to styrene process was studied. A variant of a radial type reactor in which the gas flow is from the bottom up is considered. Ethylbenzene and steam were selected as components for mixing. Ethylbenzene is supplied to the mixer at a temperature of about 600°C, and steam at a temperature of about 700°C. Three design cases for the internal devices of the mixer are considered. The analysis of the gas mixture parameters, such as volume fraction and average temperature, at the outlet of the mixer was carried out. The cases with the best mixing of the components are determined.

A mathematical model is suggested for the dehydrogenation of isoamylenes into isoprene in a fixed bed of industrial, self-regenerating, iron-potassium catalysts (KDOM and ZhKD). The model takes into account the size and shape of catalyst granules, the rate constants and activation energies of the forward (dehydrogenation) and reverses (hydrogenation) reactions, those of cracking and catalyst self-regeneration reactions, and the buildup of leachable and nonleachable coke. The mathematical model adequately describes the physical and chemical processes occurring in the dehydrogenation of isoamylenes in industrial reactors at different amounts of iron-potassium catalyst and varied reactor operation parameters (feed flow rate, degree of dilution of the feedstock with water vapor, temperature and pressure at the reactor inlet. It provides means to optimize the technological parameters of the industrial process.

The main problems associated with the operation of microspherical treating-type chromia-alumina catalysts with increased strength during isoparaffin dehydrogenation are discussed. The erosive wear of the walls of overflow pipelines when using a mixture of treating-type KDI and conventional IM-2201S catalysts and ways of solving the problem are emphasized. It is found that the main reason for an increase in erosive wear is the greater momentum of catalyst particles due to a higher mean particle size and gas transport rate; upon transitioning from IM-2201S to a mixture of IM-2201S and KDM (70 : 30), the mean particle size of the equilibrium catalyst grows from 68 to 74 μm. The optimum size range of a high-strength catalytic system in which the activity does not increase over time is calculated with a lower rate of transport gas injection while keeping the number of particles 20–40 μm in size at 20–30 wt %. Pilot batch production of high-strength catalyst in the optimum size range is recommended in order to shift units for the industrial dehydrogenation of isobutane to the use of treating-type KDI catalyst without the addition of IM-2201S.

Progress in the synthesis and applications of nanomaterials including nanocatalysts demands a use of precise analytical tools for their surface characterization. Continuous wave (cw) and pulsed electron paramagnetic resonance (EPR) techniques, including electron–nuclear double resonance (ENDOR) have been applied to study paramagnetic complexes formed by adsorption of 9,10-anthraquinone (AQ) as probe molecule by the surface of γ-Al2O3. Up to three different paramagnetic complexes (11-line pattern and two single EPR lines) could be separated in our experiments. Their spectroscopic characteristics are extracted. It is shown that at very high concentration (ca. 10 wt %) of AQ, the obtained EPR signal is close to the single line and can be incorrectly interpreted as due to the EPR signal of AQ itself or due to the lower catalytic activity of the investigated surface. That fact should be taken into account by using AQ as a probe of the surface catalytic activity. Mims and Davies ENDOR experiments confirm the re...

Mechanism of the hydrothermal modification of gamma-aluminum oxide was studied. A set of physicochemical methods demonstrated that boehmite crystals are formed in macropores (>500 nm) by the dissolution/precipitation mechanism, whereas in mesopores (

In this work, we get a numerical simulation analyzes the effect of catalyst granule size on the operation efficiency of the fixed bed reactor for the dehydrogenation of ethylbenzene to styrene. For the laboratory reactor, we built a detailed model of cylindrical catalyst granules with a length of 3 mm, 6 mm and 9 mm. We carried out an analysis of the granule size effect on the bed characteristics, such as porosity and the catalyst total surface area. We obtained results for a wide range of feed gas rates. The ranges and rates of the catalyst efficiency decrease for different feed gas rates are determined.

The purpose of this paper is to identify the phase inhomogeneity, undetectable by X-ray method, and the reason for its occurrence in the composition of aluminum oxide. It is shown that even a trace amount of carbon (0.23 wt%) in the precursor of aluminum oxide can cause a high content of amorphous phase (38%). Carbon is present due to the products of incomplete hydrolysis of the aluminum alkoxides (alumoxanes) in the commercial sample of boehmite. The fact that the amorphous and crystalline phases in the composition of aluminum oxide differ in reactivity under hydrothermal treatment is first described. It is shown in a split endothermic peak on the differential scanning calorimetry curve. It is investigated that the brief hydrothermal treatment of the phase-inhomogeneous aluminum oxide and its subsequent calcination lead to formation of a defective structure with greater acidity in the composition of the aluminum oxide. This aluminum oxide was used as a support of the palladium catalyst in the 1,3-butadiene hydrogenation. This catalyst showed higher selectivity to 1-butene and low selectivity to butane, compared to the catalyst on alumina with amorphous phase.

The promoter nature and content effects on the catalytic activity and stability of Pd-Co/δ-Al2O3 and Pd-Zn/δ-Al2O3 bimetallic catalysts in the hydrogenation of dienic and vinyl aromatic hydrocarbons in the BTX fraction have been investigated by IR spectroscopy and temperature-programmed reduction. The Pd : Co (Zn) molar ratio in the catalysts prepared is 1.0 : 0.5, 1.0 : 1.0, or 1.0 : 1.5, and their Pd content is 0.5 wt %. The support is δ-Al2O3 doped with sodium (0.5 wt %). Promotion of the palladium catalyst with zinc and cobalt causes the disappearance of cationic palladium species, thereby reducing the oligomerizing capacity of the active component, and, as was demonstrated by 100-h-long catalytic tests, enhances the stability of the catalyst. The Pd-Co/δ-Al2O3(Na) catalyst with Pd : Co = 1.0 : 1.0 mol/mol is recommended for the hydrogenation of the BTX fraction under industrial conditions. The expected service life of this catalyst between regenerations is 16 months.

KGS-3 catalyst is tested in the selective hydrogenation of methylacetylene and propadiene contained in industrial pyrolysis propane-propylene fractions at a pilot installation in two successive adiabatic flow reactors equipped with immobile catalyst beds. The optimum technological conditions for hydrogenation are determined, ensuring a residual content of acetylene and diene admixtures of no more than 5 ppm: pressure in the system, 18 atm; hydrocarbon feedstock hourly space velocity (HSV), 2100 h−1; molar ratio of hydrogen to the sum of methylacetylene and propadiene in the first and second reactors, respectively, 1.1 : 1.0 and 1.6 : 1.0; temperatures, 50 and 55 °C. Under these conditions, KGS-3 catalyst ensures 100% conversion of methylacetylene and propadiene with a propylene selectivity of 76.7%. The expected service life of this catalyst is about 14 months. The catalyst can be used for the purification of hydrocarbon fractions containing up to 5 wt % of acetylene and diene admixtures.

Using the X-ray diffraction analysis, emission spectral analysis, low-temperature nitrogen adsorption, and electron spin resonance methods, the dynamic sorption capacity in removal of carbon dioxide from gas streams, exhibited by type NaX zeolite samples, was studied in relation to their phase and elemental compositions and crystal and pore structure characteristics. It was found that the criteria determining the capacity of the zeolite are the content of the crystalline phase, imperfection of the crystal structure as determined by the crystallite size and the amount of iron isomorphously substituting the aluminum cations in the tetrahedral sites of the zeolite, and the number of compensating sodium cations.

Pilot tests of SGA-2M promoted Pd/Al2O3 catalyst in the selective hydrogenation of acetylene are performed on an industrial ethane-ethylene fraction in a system of two serially arranged adiabatic flow reactors. The optimum process conditions under which the conversion of acetylene reaches 100% at a selectivity of 68.2% with respect to ethylene are determined: system pressure, 21 atm; hydrocarbon feedstock hourly space velocity (HSV), 1500 h−1, carbon monoxide concentration, 7 ppm; H2: C2H2 molar ratio at the first and second hydrogenation stages, 1.0: 1.0 and 1.4: 1.0; inlet temperature of the first and second reactors, 40 and 55°C, respectively. The interregeneration service life of the SGA-2M catalyst under optimum conditions is estimated at 12 months. SGA-2M catalysts can be recommended for purifying ethane-ethylene fractions containing up to 2 vol % of acetylene.

The properties of the Fe2O3-K2O and Fe2O3-K2O-CeO2 model systems with weight ratios of 80 : 20 and 50 : 20: 30, respectively, are studied by means of thermal, magnetic, X-ray and dispersion analysis, and low-temperature nitrogen adsorption. It is found that the successive formation of mono- and polyferrite phase occurs during the interaction of iron oxide and potassium carbonate. It is proposed that the activity of the iron-potassium catalyst is proportional to the content of the surface monoferrite phase. It is found that introducing cerium into the iron-potassium system leads to a redistribution of potassium mono- and polyferrites in the ferrite phase, raising the proportion of monoferrite. Introducing cerium therefore promotes the activity of the catalyst system. The results from this study will be used to develop new iron-potassium catalysts with high catalytic activity in the dehydrogenation of isoamylenes into isoprene.

At the Synthetic Rubber Plant of OAO Nizhnekamskneftekhim, the dehydrogenation of isoamilenes into isoprene is currently performed on KDOM-08 catalysts with an insufficiently high yield of isoprene throughout the period of its industrial operation. More stable and highly active catalysts must be used to make the process more efficient. Under Russian Federation Government Decree No. 218, ZhKD-1 and ZhKD-2 iron-potassium catalysts have been developed by improving their formulas and optimizing their phase composition through selecting the proper ratio of initial compounds. To evaluate the possibility of transitioning to the new domestically-produced iron-potassium catalysts, we have performed pilot tests of the ZhKD-1 and ZhKD-2 catalysts in the dehydrogenation of methylbutenes into isoprene in adiabatic flow fixed-bed reactors at the Synthetic Rubber Plant of OAO Nizhnekamskneftekhim. The KDOM-08 catalyst used in the amount of 25 t in reactor 1 of the first system is taken as a base for comparison. The ZhKD-1 and ZhKD-2 catalysts are loaded into parallel reactors 7 and 8 of the fourth system. The KDOM-08 catalyst is shown to operate more efficiently under industrial conditions at loads of 1.0–2.0 t/h for 1000–3000 h, after which its performance characteristics deteriorate due to its gradual deactivation. The ZhKD-1 and ZhKD-2 catalysts are substantially superior to their industrial analogues in isoprene yield. It has been found that the ZhKD-2 catalysts operate more efficiently at even longer runs (4000–5000 h) and feedstock flow rates of 1.0–2.0 t/h, and the ZhKD-1 catalysts exhibits better activity (30–33 %) and selectivity (87–92 %) at higher loads of 2.3–3.0 t/h for up to 5000 h. From our analysis of the catalysts’ operation over the last 1000 h, it follows that at the same process temperatures (619°C) and feedstock loads (2.5 t/h), the ZhKD-1 and ZhKD-2 catalysts operate at a lower steam dilution coefficient (6.1 t/t) than the KDOM-08 catalyst (6.8 t/t). The rebuilding of reactors 7 and 8 allows the loaded catalyst mass to be reduced from 25 to 17 t, thereby almost doubling the daily output of isoprene per ton of catalyst. It is obvious that higher activity and selectivity along with smaller loads makes the use of the ZhKD-1 and ZhKD-2 catalysts economically profitable.

The rate of the endothermic process of kaolinite transformation into metakaolinite was examined by X-ray phase and thermogravimetric analyses, as well as by means of differential scanning calorimetry, in relation to the particle size distribution and crystal structure characteristics of kaolinite in kaolin clays from different deposits.

In order to obtain an efficient alumina catalyst for skeleton isomerization of n-butenes with a high catalytic activity, we study the influence of hydrothermal treatment (HTT) of alumina systems at 150–200°C on the parameters of the crystalline and pore structure, and acid-base properties of industrial γ-Al2O3. It is shown that the HTT of aluminum hydroxide increases the sizes of microcrystallites and reduces the alumina’s specific surface area and the number of acid-base centers. This reduces the activity in the reaction of skeletal isomerization of n-butenes. HTT of the two-phase alumina-aluminum hydroxide system produces smaller crystallites of γ-Al2O3 and raises the acidity of the alumina obtained after calcination at 550°C; as a result, the catalytic activity increases. This method can be used to enhance the activity of industrial samples of alumina in the reaction of skeletal isomerization of n-butenes.