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Abstract: The production of olefins via the catalytic conversion of methanol on zeolites and zeotypes is of great interest to both the scientific community and specialists in related areas of the national economy. Due to the gradual industrial implementation of the above process, the focus of attention is gradually shifting from scientific research devoted to the synthesis and modification of zeolites and zeotypes of different structures; to studies of pilot and industrial installations; to determining the main economic and environmental indicators, both existing and planned; and to the construction of production facilities. In 2019 alone, China licensed the construction of 26 production sites with a capacity of 14 million t/yr for ethylene and propylene, and commissioned 14 enterprises with a total capacity of 7.67 million t/yr for ethylene and propylene. The established production facilities include a full cycle of coal processing that consists of coal gasification units for the production of synthesis gas; units for the production and purification of methanol and olefins; and units for the production of polyethylene and polypropylene. The total productivity of the commissioned plants is more than 21 million t/yr for ethylene and propylene. This work reviews sources published in the foreign literature over the past five years on the preparation and modification of catalysts, along with technological, economic, and environmental aspects of the production of olefins from methanol. PubDate: 2022-03-01
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Abstract: The level of the main catalysts and industrial technologies for the conversion of natural gas into syngas further convrted into ammonia, methanol, and H2 was analyzed. The main trends in their development, aimed at reducing the energy and resources consumption, were described including process flowsheets, catalysts, and sorbents at different stages of methane reforming and CO steam reforming. PubDate: 2022-03-01
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Abstract: The current structure of the production and consumption of methanol is reviewed. The main processes of methanol processing and catalysts for their implementation are highlighted: the production of formaldehyde, hydrocarbons (MTH), olefins (MTO), and the production of hydrogen from methanol by means of steam reforming, partial oxidation, autothermal reforming, and decomposition. PubDate: 2022-03-01
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Abstract: The ways for the production of zeolite powders, which are currently manufactuired on an industrial scale, and their conversion into grained zeolite-containing adsorbents and catalysts are studied. Some data on the Russian manufacturers of these materials are presented. A brief overview on the utilization of these materials in adsorption drying, the purification and separation of gaseous and liquid media, and the catalytic processing of hydrocarbons in Russia and worldwide is given. PubDate: 2022-03-01
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Abstract: The state-of-the art in the catalytic conversion of natural gas containing methane as the main component to valuable chemicals and fuels is reviewed. Methane conversion processes are of considerable importance to society; like oil, they are sources of energy, fuels, and chemicals. Direct and indirect means of methane conversion are discussed. Direct methane conversion processes are commonly thought of as the Holy Grail of modern research, since the methane molecule is extremely stable. Ways of producing synthesis gas, methanol, ethylene, formaldehyde, benzene, and other compounds are considered. The main emphasis is on processes of direct methane conversion (methane dehydroaromatization). Catalysts and the conditions for their synthesis are described, the state of active sites is studied, and a mechanism of methane dehydroaromatization is proposed. The reasons for catalyst deactivation and means of catalyst regeneration mechanism are described. The review helps summarize recent advances in heterogeneous catalysis in the field of natural gas conversion. PubDate: 2022-03-01
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Abstract: The essay considers historical aspects of the appearance and development of methods for catalytic hydrogenation of organic compounds, starting from the works by P. Sabatier and V.N. Ipatieff. Particular attention is paid to the results of synthesis and investigation of hydrogenation metal catalysts based on Ni, Pd and Pt since they are significant for practical application. Modern trends and promising lines of investigation in the field of hydrogenation processes and catalysts are revealed. PubDate: 2022-03-01
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Abstract: A technology is proposed for the catalytic hydrothermal treatment of oil residues (mazut and tar) for the synthesis of high added value products, including marine fuel, that satisfy the contemporary technical and environmental requirements. The technology is based on using catalysts on an alumina support with a hierarchical structure of meso- and macropores and a high stability under severe process conditions. Data are presented from a physicochemical analysis of the chemical composition, textural and phase properties of fresh and waste catalysts for the three-stage processes of the hydrothermal treatment of mazut and tar. Variants of the implementing and combining this technology at Russian oil refineries to increase profits from oil refining are proposed on the basis of the material balance of each stage of these processes and the complex analysis of properties for the formed oil products. Introducing mazut hydrothermal treatment at oil refineries without secondary processes would improve the economic efficiency of mazut utilization by 84–170%, depending on the chosen process layout and the product box required for an enterprise. Tar hydrothermal treatment can be combined with the processes of delayed coking, catalytic cracking, and hydrocracking to increase the depth of treatment to 95% and enhance the production of such high-demand oil refining products as gasoline, diesel fuel, and marine fuel with sulfur contents of less than 0.5% and low-sulfur oil coke for the electrode manufacturing industry. The integration of tar hydrothermal treatment with secondary processes would improve the economic efficiency of tar utilization by 2–2.5 times, relative to delayed coking plants. PubDate: 2022-03-01
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Abstract: Nowadays, sugar esters (SEs) have become the focus of researchers due to their biocompatibility and extensive industrial applications as surfactants. This trend provides new methods and opportunities for the development of green synthetic chemistry. Taking the above into consideration, a critical review presented in this work emphasized the efficiency of catalyzing the synthesis of SEs with minimal hazardous by-products. Catalytic media have been employed with various impacts involving chemical, biological, and other catalytic materials. Chemical methods have been reported to show limitations in terms of preparation and biocompatibility. To solve these shortcomings, therefore, other technologies have been adopted: ionic liquids (eutectic solvents), chemo-enzymatic systems and chemo-enzymatic systems on a catalytic surface. The use of chemo-enzymatic systems on catalytic surfaces has proved to be suitable in solving biocompatibility and stability problems and correspondingly increasing the yield of esters formed. Therefore, finding an improved catalytic surface, and the sustainable optimal reaction conditions for enzymes will be vital to improving sugar ester conversion. This study highlights the different catalytic advances employed in the esterification of SEs. PubDate: 2022-03-01
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Abstract: A study on the growing importance of gas chemistry to the world economy and the resulting need to create new catalytic and non-catalytic technologies for converting natural gas and other hydrocarbon gases into chemical products is performed. Existing and promising non-catalytic processes of converting them into synthesis gas are discussed, along with direct ways of obtaining chemical products from methane, the main component of natural gas. PubDate: 2022-03-01
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Abstract: The effect of iron and manganese additives on the textural characteristics and phase composition of the alumina matrix support was studied for sulfated zirconia catalysts of hexane isomerization. The additives introduced at the stage of plastification of aluminum hydroxide significantly improved the catalyst activity (hexane conversion and selectivity of isomerization to hexane isomers). A distinction of the modified catalysts is the formation of acid sites in a ratio of LAS : BAS ≥ 2, which increase the yield of isomers and especially of high-octane 2,2-dimethylbutane. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040103
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Abstract: A report is given on the recent advances in the design, synthesis, and development of a new catalytic microreactor for the selective and continuous synthesis of value-added substances used in fine organic synthesis and pharmaceutical industry. Inside this advanced reactor, metal nanoparticles are incorporated into mesoporous materials that are deposited as very active and selective catalytic films on the walls of capillary microchannels with diameters of 220 and 530 µm. These microreactor systems require no subsequent separation of the catalyst, which allows their continuous operation. Crystalline and amorphous metal oxides based on titanium dioxide synthesized using the sol gel technique and containing catalytically active polymetallic nanoparticles are potentially the most stable coatings. The catalytic properties and operational stability of capillary microreactors are studied at atmospheric pressure and compared to those of conventional industrial batch reactors. Our Pd50Zn50/TiO2 coating displays higher activity (1.5 gMBE/(gPd s)) and selectivity (96.7%) than coatings described earlier, and retains high catalytic performance after 88 h of a reaction with Lindlar’s industrial catalyst. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040073
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Abstract: Oxygenated products from selective hydrocarbon oxidation have high commercial value as industrial feedstocks. One of the most important industrial processes is the cyclohexane oxidation to produce cyclohexanol and cyclohexanone. These organic substances have special importance in the Nylon manufacture as well as building blocks for a variety of commercially useful products. In this work we present the synthesis and characterization of a new mononuclear piperazine-derived series of iron(III) complexes and their catalytic activity towards cyclohexane oxidation essays. All complexes present octahedral high-spin iron(III) center according to elemental analysis, FTIR, UV-VIS and Mössbauer spectroscopy characterization. The cyclohexane oxidation resulted in cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide as products, with yields up to 39%. The best results were obtained with the complex (NH4)[Fe(BPPZ)Cl2] (BPPZ: lithium 1,4-bis(propanoate)piperazine) and with hydrogen peroxide as oxidant. The reactions were carried out at room temperature and atmospheric pressure, which incomes a great advantage over the current industrial process of cyclohexane production. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040036
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Abstract: Polyfunctional Ni- and Mo-containing catalysts are prepared by sequentially impregnating a support (SiO2, Al2O3, B2O3–Al2O3, \({\text{SO}}_{4}^{{2 - }}\) /Al2O3, \({\text{SO}}_{4}^{{2 - }}\) /ZrO2) using solutions of corresponding salts with intermediate steps of drying at 120°C and calcination at 500–550°C. X-ray powder diffraction, temperature programmed reduction, UV-VIS diffuse reflectance spectroscopy, and electron spin resonance spectroscopy are used to study physicochemical properties of the prepared catalysts. The catalysts are tested in the direct synthesis of propylene from ethylene at an atmospheric pressure, 200°C and an ethylene weight hourly space velocity of 0.5 h−1. The highest conversion of ethylene and yield of propylene are achieved for a sample based on borated alumina, due to the formation of active sites of ethylene dimerization, Ni2+ ions bound to acid sites of the support, and active sites of metathesis (surface monomolybdate compounds). PubDate: 2021-10-01 DOI: 10.1134/S207005042104005X
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Abstract: The effect of fluorine addition to the alumina matrix used for the preparation of supported sulfated zirconia catalysts has been studied. The fluorinating agent was hydrofluoric acid. Fluorine additions affect the textural characteristics of the Al2O3 matrix and, as a consequence, the surface area of sulfated zirconia catalysts based on modified systems. The introduction of fluorine in the catalyst composition to an increase in the activity (conversion of hexane) and yield of the high-octane isomer 2,2-dimethylbutane. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040115
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Abstract: Hydrogenation of CO2 to CO and hydrocarbons is carried out over a wide range of catalysts. Group of VIIIB transition metals have proved high conversion and selectively for CO and methane. Meanwhile, low cost and effective catalysts are preferable in an industrial scale. In this work, the synergistic effect of iron content on the catalytic performance were investigated in carbon dioxide hydrogenation reaction. Incipient wetness impregnation procedure was used for the preparation of four γ-Al2O3 supported iron-based catalysts. BET, XRD, H2-TPR and TEM techniques were employed for the catalyst characterization. The evaluation of catalysts were carried out in a fixed bed reactor at the process conditions of temperature of 300°C, pressure of 20 atm, H2 to CO2 ratio of 3 and GHSV of 3 NL/(h gCat). It was found that the promoter addition improves the activity of Fe catalyst for both Fischer-Tropsch synthesis (FTS) and Reverse Water Gas Shift (RWGS) reactions. The results showed that conversion of CO2 was from 15.6 to 35.6% with major products of methane, C2 to C4, C5+ and CO. It was also found that impact of K and Ce promoters into iron catalyst showed the highest conversion and hydrocarbon yield due to the synergistic effect. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040085
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Abstract: The oligomerization of ethylene in aliphatic and aromatic solvents on complex zirconium carboxylate catalytic systems obtained from naphthenic acid fractions isolated from Baku oils is studied for the first time. Comparative studies are performed using complex zirconium carboxylate catalytic systems obtained from individual carboxylic acids CH3(CH2)2COOH and CH3(CH2)8COOH. It is found that the activity of a catalyst and the molecular weight distribution (MWD) of oligomeric products depend mainly on the solvent and the composition of the zirconium complex. It is shown that the rate of ethylene oligomerization when using zirconium carboxylate catalytic systems in aliphatic solvents is 2–3 times lower than in aromatic solvents. The resulting product has a narrow MWD and consists mainly of C4–C10 fractions. The oligomeric products obtained in aromatic solvents have wide MWDs and consist mainly of C4–C18 in the presence of zirconium carboxylates and of C12–C18 and C20 fractions with zirconium naphthenates. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040048
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Abstract: The second part of a series of reviews on the direct synthesis of organotin compounds is presented. In this part, the conditions and results of the reaction between metallic tin and allkyl halides are considered. The efficiency of application is analyzed for different catalysts along side with their systematization, and some possible mechanisms of these processes are discussed. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040127
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Abstract: The effect of the tungsten oxide content (10–35 wt %) in Pt/WO3-ZrO2 catalysts on hydroisomerization of a heptane–benzene mixture (80 : 20, wt %) has been studied. The catalysts with 15–25 wt % WO3 are characterized by the highest fraction of the tetragonal phase of zirconia (t-ZrO2, 87–96%), which makes it possible to achieve the highest yield of the sum of heptane isomers, including high-octane di- and trimethyl-substituted isomers (DTMS; 69.4–76.7 and 24.5–27.9 wt %, respectively). In the presence of these catalysts, the yield of methylcyclopentane is 52.1–61.3 wt % at 72.6–90.9% selectivity of isomerization of cyclohexane to methylcyclopentane. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040097
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Abstract: The effect of 0.3 wt % of indium introduced at the peptization and aluminum oxide impregnation stages on the properties of alumina-platinum reforming catalysts has been studied. Modification with indium at the impregnation stage reduces the total acidity of the support to a lesser extent and, as a consequence, the conversion of heptane for the corresponding Pt/In/Al2O3-Cl catalyst. This sample demonstrates the greatest decrease in the selectivity of the hydrogenolysis and hydrocracking reaction alongside with a maximum ratio of i-C5–7/toluene selectivities as compared to the catalysis doped with In at the peptization stage and without doping. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040139
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Abstract: A study is performed for the aldol condensation of formaldehyde with dihydroxyacetone (DHA) in an aqueous medium (pH 7.54–8.71) at 65–80°C using zinc zeolitic imidazolate frameworks based on 2-methylimidazole (ZIF-8) and 2-ethylimidazole (MAF-5 and MAF-6). It is shown that the selectivity of the process depends on the pH of the reaction solution, which is controlled by the temperature of the reaction and the amount of catalyst in the reaction mixture. There are high yields of C6 sugars when the reaction is conducted at pH 8.36 and 80°C. The sugars are accompanied by high yields of erythrulose (39–60%) at a temperature of 65°C and. It is found that the yield of erythrulose when using the studied catalytic systems depends on the pore radius and grows in the order MAF-6 > MAF-5 > ZIF-8. The advantages of the studied systems are compared to those of homogeneous and heterogeneous phosphate systems proposed in the literature. PubDate: 2021-10-01 DOI: 10.1134/S2070050421040061
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