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Abstract: The problem of trapping solid particles in a production line with dehydrogenation of C4–C5 isoparaffins to iso-olefins in a fluidized catalyst bed was considered. Dust collection of fine catalyst particles for paraffin dehydrogenation units using a standard TsN-15 cyclone and a new dust collector (NDC) with arc-shaped elements was studied. The results of numerical simulation of TsN-15 and NDC were presented. Comparative studies showed NDC to be more efficient than TsN-15 for trapping fine solid particles with sizes of less than 20 μm. The pressure and flow velocity profiles for NDC were shown to change as a regular tendency, without any critical deviations. The gas flow velocity through the arc-shaped NDC elements was shown to be stable in contrast to TsN-15, which creates high flow velocities at the cyclone periphery to increase the probability of dust breakthrough into the flow. PubDate: 2022-12-01
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Abstract: The reactivity of adsorbed acetic acid forms on the Pt–ReOx/TiO2 catalyst has been studied. Three adsorbed acetic acid forms were identified by in situ Fourier IR spectroscopy at 200°С: bidentate acetates and two forms of molecularly adsorbed acetic acid. The consumption rate constants two forms of molecularly adsorbed acetic acid (0.02 and 0.029 s–1, respectively) were found to be close in magnitude to the catalytic reaction constant rate (0.034 s–1) measured at 200°С. It was concluded that these two forms of molecularly adsorbed acetic acid are key intermediates in acetic acid hydrogenation on the Pt–ReOx/TiO2 catalyst. PubDate: 2022-12-01
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Abstract: Results of studying the sorption-enhanced water gas shift reaction over a mechanical mixture of grains of 5 wt % Pt/Ce0.75Zr0.25O2 catalyst and 10 wt % NaNO3/MgO sorbent are presented. It is shown that pure magnesium oxide sorbs virtually no СО2 under model conditions, while its promotion with NaNO3 substantially improves the dynamic sorption capacity in the 300–350°C range of temperatures with a maximum at 320°C. The catalyst shows high activity and selectivity in the water gas shift reaction for a model mixture (CO, 11.6; H2, 61; H2O, 27.4 vol %). The concentration of CO at the outlet from the reactor is less than 1 vol % in the 220–400°C range of temperatures (the minimum is 0.3 vol % at 240°C) with СН4 at the temperatures below 320°C (0.61 vol % at this point). Using this sorbent in mixtures with a catalyst in the sorption-enhanced water gas shift reaction at 320°C substantially reduces its sorption capacity, due probably to the full conversion of NaNO3 into Na2CO3 that is not completely decomposed at the stage of regeneration. This nevertheless allows the outlet СО and СН4 concentrations to be halved, relative to values observed at this temperature in experiments with no sorbent: 6.1 × 10−4 and 8.2 × 10−2 vol % per dry gas basis at the middle of the first adsorption cycle. Prospects for using this approach in the sorption-enhanced water gas shift reaction and the need for further studies on improving the capacity and stability of the presented sorbents are described. PubDate: 2022-12-01
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Abstract: The technical feasibility of the direct monetization of associated petroleum gas currently burned is considered. The proposed approach is based on the low-temperature steam reforming of hydrocarbons, with which flare gases can be brought to meet the requirements for fuel used in gas piston and turbine power plants. The preparation and catalytic properties of new rhodium-based catalysts for low-temperature steam reforming of flare gas are discussed. Mixed cerium zirconium oxides are the most promising catalyst supports. Such catalysts have a number of advantages over the known nickel catalysts in the low-temperature steam reforming of hydrocarbons. PubDate: 2022-12-01
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Abstract: The processes for the production of basic monomers at Nizhnekamskneftekhim via dehydrogenation are described. The cooperative development of modern domestic catalysts with the Kazan Federal University is emphasized. The disadvantages of existing catalytic systems are considered, and the possivle ways of their elimination are presented. PubDate: 2022-12-01
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Abstract: The effect of the type of polysaccharide support for immobilization and encapsulation on the stability of chymotrypsin was studied. The synthesized biocatalysts were compared according to their proteolytic activity. The cellulose–chitosan composite was found to have the highest proteolytic activity equal to 192 units/g. Immobilization was found to slightly change the optimum temperature and pH of chymotrypsin, but they substantially grew toward higher temperatures and alkaline pH values. The greatest relative increase in the activity of immobilized chymotrypsin was observed when using the cellulose–chitosan composite. The activity of chymotrypsin changed by no more than 45–50% during storage of the cellulose–chitosan and cellulose–alginate composites for 24 months. According to the results of our study, the cellulose–chitosan composite was the optimum support for immobilization of chymotrypsin. PubDate: 2022-12-01
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Abstract: The in situ formation of a catalytic heterohomogeneous system containing Al–M alloy (M is Ni, Co, Cu) and Al(M)/Cl complex in a benzene–ethylene medium at a temperature of 80°C and a pressure of 0.2–0.3 MPa is studied. The characteristic patterns of interaction between Al–M alloys activated with a liquid metal Ga–In eutectic and a chlorinating agent (CCl4) with the formation of catalytically active metal–aluminum chloride Al(M)/Cl complexes are established. Results from spectrokinetic measurements show the order of the reactivity of activated alloys with respect to excess CCl4 is Al–Cu ≈ Al–Ni > Al > Al–Co. The highest catalytic activity is displayed by nickel–aluminum chloride complexes whose selectivity toward ethylbenzene is 48%. Data from IR and UV-VIS spectroscopy show that the structure and composition of metal chloride complexes formed in situ in the aromatic reaction medium is determined by a combination of coupled ionic pairs \([{\text{AlC}}{{{\text{l}}}_{4}}]_{{{\text{tetr}}}}^{ - }{\text{/[NiC}}{{{\text{l}}}_{{\text{6}}}}]_{{{\text{oct}}}}^{{4-}}\) and \(\left[ {{\text{AlC}}{{{\text{l}}}_{{\text{4}}}}} \right]_{{{\text{tetr}}}}^{ - }/\left[ {{\text{CuC}}{{{\text{l}}}_{{\text{2}}}}} \right]_{{{\text{lin}}}}^{ - }\) , which are stabilized by (C6H5)3C+ carbocation. PubDate: 2022-12-01
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Abstract: A study of original iron–potassium catalysts of ethylbenzene (EB) dehydrogenation to styrene and industrially used catalysts: Cat-1 (imported), Cat-2 and Cat-3 (domestic) is performed. Initial samples are multiphase systems consisting of potassium ferrites, hematite, and cerianite (CeO2). The phase composition of the catalysts after two years of operation consists mainly of magnetite and cerianite, while the amount of potassium (K+) in Cat-1, Cat-2, and Cat-3 samples falls by 40, 20, and 26%, respectively. At the same time, K+ for the Cat-2 sample is distributed uniformly in granules of the waste catalyst. XRD data indicate the CSR size of its CeO2 crystals does not change appreciably. The CSR size of CeO2 crystals in the Cat-3 sample falls from 302 to 110 Å, while it grows from 284 to 419 Å in the Cat-1 sample. After two years of operation, the greatest conversion of EB (72.1%) was observed for the Cat-2 sample, and it fell from 72.3 to 57.4% on the Cat-3 sample. There is a 600–1100% drop in the waste samples’ resistance to crushing, making them unsuitable for further use. PubDate: 2022-12-01
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Abstract: The activity and selectivity of sulfidized and non- sulfidized palladium alumina supported catalysts in the hydrogenation of 1,3-pentadiene to pentenes is studied. Preliminary sulfidation of palladium catalysts substantially improves their selectivity toward olefins in a broad range of Н2 : diene ratios (from 2.5 to 10). Samples activated in Н2 at elevated temperatures display higher activity in diene hydrogenation. Palladium catalysts are more active at low temperatures of the reaction, but sulfidized Ni catalysts studied earlier are competitive with palladium ones in selectivity toward olefins and productivity, and are more selective in an excess of hydrogen. The modification of palladium with chromium, silver, or lithium improves the selectivity toward olefin. PubDate: 2022-12-01
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Abstract: The experimence from cooperation with industrial petrachemical and oil refining enterprises in implementation of developments is systematized. The important role of cooperation and interdisciplinary studies is highlighted, and the interaction between consumers and manufacturers of catalysts is considered. The most important stages of the development and implementation of catalysts are described. PubDate: 2022-12-01
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Abstract: Diesel vehicles release not only soot and NOx into the environment, but also a wide range of organic and inorganic toxic compounds. The review discusses in detail the role of the oxidation catalyst in modern diesel exhaust purification systems, methods for improvement and optimization of oxidation catalysts designed for conversion of carbon monoxide and hydrocarbons, and methods for reducing the contents of Pt group metals in these catalytic systems. PubDate: 2022-09-01 DOI: 10.1134/S2070050422030060
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Abstract: This paper is a review of acetylene production technologies, which are both used for a long time in industry and currently at the stage of laboratiory studies and demonstration testbenches. The possibility of transition from acetylene production technologies accompanied by the formation of substantial amounts of greenhouse gases (carbide technology, oxidative natural gas pyrolysis) to low-carbon or carbon-free natural gas and coal plasmochemical processes using energy generated by renewable sources (wind and solar) is considered. PubDate: 2022-09-01 DOI: 10.1134/S2070050422030023
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Abstract: The data on the development and study of new catalysts for the reforming and isomerization of gasoline fractions from the Center of New Chemical Technologies BIC (Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences), including the experience in the industrial appliction of reforming catalyst PR-81, are presented. A new catalyst of increased acidity is developed for the reforming of gasoline fractions to ensure a 3–5 wt % reduction in the content of aromatic hydrocarbons in the reformate. A new sulfated zirconia catalyst supported on a porous alumina matrix is developed for the isomerization of the C5–C6 hydrocarbon fraction. An efficient catalyst based on tungstated zirconia is proposed for isomerization of the С7 hydrocarbon fraction. A flowsheet of integrated reforming and isomerization processes is proposed on the basis of the new catalysts to ensure the production of Euro-5 and Euro-6 motor gasolines alongside promising gasolines with reduced contents of aromatic hydrocarbons. PubDate: 2022-09-01 DOI: 10.1134/S2070050422030035
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Abstract: This work is the third and final part of a series of reviews devoted to the direct synthesis of organotin compounds. This part of the series considers the conditions of and results from the reaction between metallic tin and carbofunctional organohalides. The efficiency of catalysts and the prospects for direct synthesis in the production of carbofunctional organotin compounds are analyzed. PubDate: 2022-09-01 DOI: 10.1134/S2070050422030047
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Abstract: The review presents an analysis of the current state in the field of partial oxidation of alcohols to carbonyl compounds on Ag catalysts, including the partial oxidation of methanol to formaldehyde, oxidation of ethylene glycol to glyoxal, and oxidation of ethanol to acetaldehyde. For methanol oxidation, conditions for BASF and ICI processes were considered, and the whole chain of transformations from natural gas to formaldehyde was evaluated from the viewpoint of exergy. Recent publications on the kinetics of partial oxidations of alcohols on silver were analyzed, including those that considered the use of a ring-shaped reactor to suppress the homogeneous decomposition stages of formaldehyde, the development of a new approach to process modeling taking into account different degrees of catalyst reactivity, and the creation of a simulator for calculating methanol oxidation based on a neural network using a genetic algorithm. The main stages of process development of partial oxidation of ethylene glycol to glyoxal on Ag catalysts are briefly described. Recent experimental and theoretical studies on the mechanisms of formation of oxygen-containing active sites on the silver surface and their participation in the conversion of alcohols into carbonyl compounds, as well as new Ag-containing catalytic composites, are presented. PubDate: 2022-09-01 DOI: 10.1134/S2070050422030059
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Abstract: The effect of acid activation with 0.125–0.5 M Н2SO4, HCl, and HNO3 on the physicochemical properties and catalytic performance of natural clay (the Mukhartalinskii deposit) containing 95% montmorillonite (MM) was investigated in the synthesis of solketal [(2,2-dimethyl 1,3-dioxolan-4-yl)methanol] from glycerol and acetone. The reaction rate and selectivity toward solketal are shown to depend on the type and concentration of acid. Both the yield of solketal and the reaction rate rose with increasing acid concentration, which correlates with the increase in the number of Brønsted acid sites. The efficiency of the system was found to diminish in the order MM/HCl > MM/HNO3 > MM/H2SO4 as the surface acidity decreased. PubDate: 2022-06-01 DOI: 10.1134/S2070050422020040
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Abstract: This review focused to the discussion of the results from recent research in a promising area of the complex processing of lignocellulosic biomass: reductive catalytic fractionation (RCF). The effect catalysts, co-catalysts, solvents, sources of hydrogen, and the nature of lignocellulosic raw materials on the selectivity in the production of monomeric lignin products is considered. Heterogeneous catalysts are mainly used in RCF processes, which allows the reductive depolymerization of lignin to obtain low molecular weight compounds while maintaining the carbohydrate components of the biomass. Of the considered catalysts based on platinum group and transition metals, those containing Pd, Pt, Ru, and Ni have the highest activity. The nature of the metal also affects the composition of the resulting products. For example, ruthenium catalysts produce 4-propyl guaiacol as the main product, while ones based on Ni and Pd yield 4-propanol guaiacol. Catalysts containing Mo, due to their lower hydrogenation activity, give monolignols or their esterified derivatives of while preserving the carbohydrate components of lignocellulosic biomass. However, bifunctional catalysts that contain both acidic and metallic active sites are the most efficient in RCF processes. Acid sites contribute to the breaking of etheric β-O-4 bonds, while metal sites catalyze reduction of the resulting intermediate compounds. An important aspect of selecting suitable catalysts for the RCF process is their reusability. The use of a ferromagnetic catalyst or a basket for the catalyst solves the problem of separating it from products of the process. PubDate: 2022-06-01 DOI: 10.1134/S2070050422020052
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Abstract: A study is performed by using a zinc–copper catalyst for the steam reforming of CO NIAP-06-06 in the synthesis of methanol. The catalyst is characterized via the TPV of N2, XRF, and SEM. It is tested in the synthesis of methanol in flow and circulation modes at a pressure of 5.0 MPa, GHSV of 3000 h−1, and the 220–260°C range of temperatures. It is shown that the catalyst has high activity and selectivity in synthesizing methanol from gas obtained in the ratio H2 : CO = 3.9 via the steam reforming of methane. Using a series of tubular catalytic reactors in the technological mode of a flow circle allows more than 70% of the CO to be processed and raw methanol to be obtained with a concentration of 95%. The performance of the catalyst for methanol is 427.7 kg/( \({\text{m}}_{{{\text{cat}}}}^{3}\) h) in the circulation mode. PubDate: 2022-06-01 DOI: 10.1134/S2070050422020064
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Abstract: Commercial super cross-linked polystyrene (SPS) is a promising support for creating heterogeneous catalysts designed for processes of fine organic synthesis. Results from years of studying the creation of heterogeneous Pd-, Pt-, and Ru-containing catalysts based on SPS of grades MN100 and MN270. Data are presented from characterizing SPS and catalysts based on them using a complex of physical and physicochemical means of analysis. It is shown that commercial SPS can be used to synthesize catalysts in the form of spherical grains or preliminarily ground powders. Along with the nature of a metal catalyst precursor, the form of an SPS has a strong effect on the distribution of Pd, Pt, and Ru compounds and the size of metal-containing nanoparticles formed in the polymer’s medium. The catalysts in a hydrogen flow at a temperature of 300°C on the surface chemical composition of powder MN100 samples impregnated w Pd, Pt, and Ru compounds is considered for the first time. PubDate: 2022-06-01 DOI: 10.1134/S2070050422020027
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Abstract: Ni-containing catalysts are obtained on the basis of carbon mineral supports produced using sapropel and studied during the catalytic hydroliquefaction of sapropel. It is found that catalysts on supports obtained from mineral-type sapropel are more active than ones on supports based on organic-type sapropel, while bimetallic NiW catalysts exhibit higher activity than monometallic nickel catalysts, regardless of the nature of the support. It is shown that both the nature of the deposited metal and the support composition affect the conversion of the organic matter of sapropel and the composition of liquid products. The liquid products of hydroliquefaction contain mainly nitrogen- and oxygen-containing compounds. The maximum yield of hydrocarbons C5–C21 is obtained for catalysts on supports obtained from mineral-type sapropel. Liquid products of hydroliquefaction of sapropels are similar in composition to biofuels from other renewable raw materials and can be included in existing schemes for further processing. PubDate: 2022-06-01 DOI: 10.1134/S2070050422020106
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