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No 3 (2012)
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CATALYSIS IN CHEMICAL AND PETROCHEMICAL INDUSTRY

9-15 735
Abstract

Hydroxylation of phenol with nitrous oxide on the zeolite catalysts offers a promising new way for the development of gas-phase process of obtaining dihydroxybenzene belonging to one of the most important precursors of modern organic chemistry. Process on the basis of this reaction may be an alternative to existing liquid-phase process, based on the use of hydrogen peroxide as an oxidant. In the present work the regularities of oxidation of phenol with nitrous oxide on zeolite MFI in the temperature range 450–500 °С reaction at 1,7–3,4 times of contact with the study. The performance of dihydroxybenzene per unit weight of catalyst was 2,3 mmol/g·h. Process with nitrous oxide has an advantage over other technologies for the utilization ratio of oxidizer and dihydroxybenzene isomers. Namely, the more complete the utilization of the oxidant (selective conversion of nitrous oxide in dihydroxybenzene 74 %) and the ratio of hydroquinone to the pyrocatechol in the reaction products 1,2–1,4.

15-20 4219
Abstract

There is study of the original two-step producing process of ethylene and propylene from natural gas by catalytic pyrolysis of methyl chloride produced by oxidative chlorination of methane. There are study of the kinetics of methyl chloride catalytic pyrolysis on the silico-alumino-phosphate catalyst SAPO-34, and determination the parameters of the process, providing 70 % conversion of methyl chloride and selectivity of ethylene – 45 %, propylene – 35 %. Kinetics of the oxidative chlorination of methane on the catalyst which represents mixture of copper chloride, potassium, and lanthanum deposited on a support was studied. Based on the results of kinetic studies in this paper, the authors tested the process of oxidative chlorination of methane in the pilot plant in reactors of different types – a fluidized bed reactor (diameter – 400 and 45 mm), tubular (diameter – 27 mm) and a pilot plant in two-stage adiabatic reactor (diameter – 800 mm). The process of checking with the supply of oxygen distributed to each stage at a temperature of 300–320 °С inlet and a 400–420 °С at the outlet of the catalyst bed. The selectivity of formation of methyl chloride in the amount chloromethanes equal to 90%. Schematic diagram of a balanced chlorine process of producing ethylene and propylene from natural gas was developed, the conditions of the reactions of oxy-chlorination of methane and methyl chloride in the pyrolysis of industrial reactors are determined. The implementation process will be primarily at plants in need of increasing the output of ethylene to vinyl chloride deficit and have experience working with hydrochloric acid and chlorinated hydrocarbons.

20-25 721
Abstract

Bio alcohols, especially bio-ethanol, due to the rapid growth of its production may be a promising renewable chemical feedstock for the production of many useful products of organic synthesis. In order to develop new «green» technologies of ethanol in the valueadded products the authors conducted a systematic study of the selective conversion of ethanol oxidation in molecular oxygen in the gas-phase flow regime on these catalysts, as V2O5–TiO2, mixed oxides of V–Mo–Te, V–Mo–Nb and V–Mo–Te–Nb, as well as gold, deposited on oxide supports. The catalytic activity was determined in a temperature-programmed reaction at atmospheric pressure in the gas mixture composition (mol%): EtOH – 2, O2 – 18, He – 80, with a mixture of volume flow rate 3600 h–1, a catalyst fraction 0,25–0,5 mm. In some cases, there is the possibility of efficient conversion of ethanol into the products of partial oxidation and related transformations – acetaldehyde (yield 90–99 %), acetic acid (yield 92–98 %, the performance of > 3 g g-cat.–1 h–1), a mixture of acetic acid and ethyl acetate (ratio ~ 1 : 1, the total yield of > 90 %).

25-29 585
Abstract

Currently microheterogeneous titanium catalyst is widely used to produce stereoregular polyisoprene, which is one of the largeproducts of modern manufacture of synthetic rubber. In the work the regularity of titanium catalyst formation at temperatures of (–10)÷(–15) °C and the polymerization of isoprene in the medium aliphatic solvent (isopentane) in changes of suspension motion hydrodynamic regime of the catalytically active particles are considered. For this purpose, the mixing is enhanced due to the turbulence of the suspension flow in the external recirculation loop during the entire process of active sites formation and their selection for the polymerization. Small tubular turbulent apparatus of diffuser-confusor design used in this stage for the first time. Polymerization of isoprene occurs on one type of centers, forming a polymer with narrow molecular weight distribution (polydispersity coefficient is 2,1–2,8). Hydrodynamic effects on the titanium industry microheterogeneous catalyst in the process of pre-formation by circulating in a tubular device, confusor diffuser design provides a more reactive centers of the macromolecules growth. This leads to the synthesis of more stable in the parameter «Mooney viscosity» of high polyisoprene. Modification of the titanium catalyst due to hydrodynamic effects on the suspension of the catalytically active species in the formation of the catalytic system is an effective way to improve the appropriate stage of the industrial production of polyisoprene.

СATALYSIS IN PETROLEUM REFINING INDUSTRY

30-37 647
Abstract

The possibility of massive catalysts synthesis using the mechanochemical activation (MCA), which is the basis for a non-waste technology of production of catalysts with particle sizes less than 10 microns is shown in the work. The predecessors of Ni-Mo catalysts for hydrogenation processes were synthesized by MCA. The chemical, phase composition and specific surface area of mechanically-activated composites with an atomic ratio of Ni: Mo = 1,0 and 1,4 were studied using the methods of DTA, XRD, TPR and low-temperature adsorption. It was established that during a joint MCA of salts containing Ni-and Mo-, solid-state reactions take place with the formation of complex X-ray amorphous compounds, which, after heating at 520 °С form nickel molybdates, which almost entirely composed of highly modified β-NiMoO4, sulfide which leads to the formation of phases MoS2, Ni3S2. There is comparative testing of sulfide catalysts – massive (Ni : Mo = 1,4), and commercial supported in the model conversion reactions of 1-methylnaphthalene and dibenzothiophene at 350 °C, 3,5 MPa pressure, mass flow rate of feed 2 h–1, the ratio of hydrogen/materials equal 600. The conclusion about the higher hydrogenating activity of the massive catalyst is made by composition of the conversion products of 1-methylnaphthalene and dibenzothiophene.

37-43 1155
Abstract

The process of hydroisomerization of benzene is one of the most promising processes to convert benzene to methylcyclopentane (MCP) – a more environmentally friendly and octane components of motor fuels. In this paper the authors study the characteristics of the hydroisomerization reaction of benzene to MCP on catalytic system Pt/MOR/Al2O3 (MOR-mordenite). Influence of acidic properties of the support and platinum predecessor (in the form of [Pt (NH3)4]Cl2 and H2PtCl6) on the yield of the desired product was studied in order to optimize the composition of the catalyst. Changing the acidity of the surface was carried out by the introduction of aluminum oxide in an amount of from 30 to 95 wt.% in the support. The catalytic activity of the samples was measured in the reactions of hydroisomerization of cyclohexane and benzene/ n-heptane (20/80 by weight) in a flow reactor in the temperature range 250–350 °C at a pressure of 1,5 MPa, H2/CH = 3/1, the volume rate filing of cyclohexane – 6 h–1, mixed raw material – 2 h–1, the amount of catalyst – 2 cm3, the fraction 0,25–0,75 mm. Found that the most efficient in the isomerization of cyclohexane, n-heptane and hydroisomerization of benzene is a platinum catalyst (0,3 wt.% Pt), whose support contains 30 wt.% MOR and 70 wt.% Al2O3. The maximum yield of target products of isomerization in the presence of that catalyst obtained in the temperature range 280–310 °C, what the thermodynamically favorable for the process of formation of methylcyclopentane from benzene, indicating that its prospects for application in hydroisomerization of benzene-containing gasoline fractions. Application H2PtCl6 acid as a precursor of platinum ensures the availability of reagents for the preparation of commercial batches of catalyst and attractive pricing for its industrial production.

СATALYSIS AND ENVIRONMENT PROTECTION

44-49 596
Abstract

Nanostructured solid solution of Mn0,5Ce0,5O2 is synthesized in order to develop an efficient catalysts for detoxification of man-made pollutants that do not contain precious metals. Its chemical and phase composition, texture characteristics were studied by DTA, XRD, laser mass spectrometry and low-temperature nitrogen adsorption. The activity of the solid solution is determined by the flow method in the oxidation of carbon monoxide in the temperature range 20– 300 ° C at atmospheric pressure, space velocity of the gas mixture 1800 h–1 and the composition of the gas mixture (vol.%): CO – 3,6, O2 – 8,0; N2 – balance. It is shown that the activity of Mn0,5Ce0,5O2 significantly higher activity MnOx and CeO2: 100% conversion temperature of – 92, 120, 210 ° C, respectively. Nanostructured catalysts Su/Mn0,5Ce0,5O2 and Ag/Mn0,5Ce0,5O2 prepared by impregnation method using a solid solution as a support. These catalysts show a high activity in the oxidation of carbon monoxide: the temperature of 100 % conversion is – 77 °С and 85 °C, respectively. New catalysts are of interest for the cleaning processes of vehicle emissions and industrial enterprises.

INDUSTRY ENGINEERING PROBLEMS. OPERATION AND PRODUCTION

50-57 709
Abstract

Construction and operating results of the thermal catalytic incineration
of solid fuel destined for the local heating of industrial and social objects are discussed. The advantage of plants is the ability to regulate a wide range of heat output (from 0,5 to 10 Gcal/h) and environmentally friendly to burn various types of solid fuels, including low-quality and waste. The data on industrial use of catalytic boiler heat output 3 Gcal/h are shown.

57-61 709
Abstract

In this paper the stages of evolution of hydrocarbon conversion catalysts forms is traced. On the basis of author’s own data it’s shown how the properties of the catalyst bed changing at each stage. The need to transition from a cylindrical base form of hydrocarbon conversion catalysts to the spherical form is justified. It is shown experimentally and by the results of commercial use in an industrial reformer of ammonia plants, the use of spherical granules of the catalyst significantly reduces the pressure drop on furnace for routine performance, and increases the productivity of the furnace, without exceeding its reconstruction and routine drop. The results of precise measurements of the resistance of the granular layer of granules of modern catalysts for complex shapes in the real linear velocity and Reynolds number are given. Data of the macrokinetic studies confirmed the proximity of the surface of the rate constants for the methane steam reforming nickel catalyst complex shape.

DOMESTIC CATALYST

62-65 555
Abstract

«Termokem» company (Chernogolovka, Moscow region, Russia) develops and manufactures catalysts deposited mesh with the active metal phase (platinum, palladium, chromium, cobalt, nickel, etc.). Several Russian patents are obtained, technical specifications are approved, pilot plants are operated. Beginning in 2005, the catalyst was applied in eight plants in Russia. The catalysts used in ammonia oxidation stage at many Russian enterprises for the production of weak nitric acid units of AK-72 (3,5/11 kgf/cm2), UKL-7 (7,3 kgf/cm2) and units of atmospheric pressure (1/3,5 kgf/cm2) in the production of hydroxyl amine sulfate devices and catalytic post-combustion-cal industrial gas emissions. They can be used in the process of hydrogenation,
afterburning exhaust of internal combustion engines, oil refining processes.

65-75 1796
Abstract

Microspherical aluminum-chromium catalyst KDM is designed for the process of isobutane dehydrogenation in a fluidized bed, it has a high catalytic activity, selectivity and thermal stability. Technology of preparation of KDM is based on the alumina support obtained by the centrifugal thermal activation (CTA) of gibbsite – Technology TseflarTM. This technology allows to control a wide range of product phase composition of the CTA products and to synthesize based on this a support with given structural and textural characteristics. Technology of catalyst and support production is mastered at the industrial scale («Altaylyuminofor» company). Beginning in 2008, the catalyst KDM was commissioned in some enterprises of «Sibur Holding» (Russia) and «Ecooil» company (Omsk, Russia). Industry experience has shown that the operation of mixture of IM-2201 with the KDM leads to a significant reduction in catalyst consumption rates (kg/tonne of isobutylene): 22–23 with the pure IM-2201 to 8–9,5 on a mixture of KDM and MI-2201. In order to further improve the catalyst KDM, the fundamental studies on the nature of the active catalyst component were carried out: they defines the role of the different states of deposited chromium oxide particles in the process of dehydrogenation and designed approaches targeted regulation of the content of active and selective chromium oxide particles. As a result, developed an improved modification of the catalyst activity and selectivity performance increased by 2–4 wt.%.

76-83 965
Abstract

Currently, the catalyst KDOM-08 show a not enough high yield of isoprene in the process of isoamylenes to isoprene dehydrogenation during the whole period of commercial operation at «Nizhnekamskneftekhim » plant. In order to increase the effectiveness the introduction of a more stable and highly active catalysts are needed. According of the Russian Federation Government Resolution № 218 еру iron-potassium catalysts ZhKD-1 and ZhKD-2 were developed by improving the formula and optimization of the phase composition by the proper selection of the ratio of initial components. To assess the possibility of transition to the new operation of iron-potassium catalysts for domestic production of pilot testing the ZhKD-1 and ZhKD-2 Rubber Plant «Nizhnekamskneftekhim» in the process of dehydrogenation of methyl butenes in the isoprene in the adiabatic flow reactor with fixed catalyst bed held. The reference sample was the catalyst KDOM-08, operated in the reactor number 1 of the first system in the amount of 25 t. Catalysts ZhKD-1 and ZhKD-2 were loaded into the reactors № 7 and № 8 of the fourth system operating in parallel. It is shown that the catalyst KDOM-08 in an industrial operation is more efficient at loads 1–2 tons/h for 1–3 thousand hours, after which it’s decrease in operating performance due to its gradual deactivation. Catalysts for the ZhKD-1 and ZhKD-2 are significantly higher than the industrial output of an analogue of isoprene. Found that the more efficient operation even in the later stages (4–5 thousand hours) at a feed flow 1–2 t/h is observed in the work on the catalyst ZhKD-2, and the ZhKD-1 before 5 thousand hours has the best indicators of activity (30–33 %) and selectivity (87–92 %) at higher loads of 2,3–3,0 t/h. Analysis of the catalysts operation for the last 1000 h showed that at equal temperatures of the process (619 °C) and equal loading of feed (2,5 t/h), the ZhKD- 1 and ZhKD-2 operated at a lower dilution of the feed with steam (6,1 t/t) compared with KDOM-08 (6,8 t/t). After the reconstruction of reactor number 7 and number 8, the mass of the loaded catalyst decreased from 25 to 17 tons, the daily production of isoprene increased by 1 m of the catalyst in almost 2 times. Obviously, the higher values of the activity and selectivity, as well as a smaller volume loading operation makes the ZhKD-1 and ZhKD-2 catalysts economically feasible.

BIOCATALYSIS

84-91 1041
Abstract

The review deals with the problem of producing motor fuels from renewable raw materials by catalytic processing of inedible vegetable oils and fats. Characteristics of different types of nonfood raw materials is presented: algae, not suitable for plant nutrition, products of wood processing, waste fats and oils. Catalytic processes for biodiesel production by the second generation y the hydro-deoxygenation and deoxygenation of triglycerides, fatty acids and their derivatives are considered. A summary of the deoxygenation catalysts of fatty acids is given. The mechanism and kinetics of deoxygenation reaction is considered especially carefully. On the basis of kinetic and quantum chemical studies involving literature data the authors proposed a mechanism for deoxygenation, which explains the observed dependence of the contributions decarboxylation and decarbonylation of the reaction conditions (concentration of stearic acid, water, catalyst, hydrogen pressure, and CO, temperature). Examples of the use of biodiesel in the transport of hydrocarbon shows.

CHRONICLE



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ISSN 1816-0387 (Print)
ISSN 2413-6476 (Online)