Chemical Engineering. Mathematical Simulation of Processes and Reactors

FIXED BED REACTORS WITH GRADIENT CATALYSTS

V.M. Khanaev, E.S. Borisova, A.S. Noskov

Nova Sci. Publishers, Inc., 2008, 103 pp.

At present, the ideas of gradient catalysts are used for creation the new type of afterburning catalysts, for microchannel reactors. In the theoretical investigation the attention is being increasingly focused on the complex approach based on the optimization of heat- and mass transfer and of the activity of the whole catalyst bed through the optimal bed packing, granule shape, distribution of the active component, heat conductivity etc., i.e. through creation of some optimal gradient medium for conducting the catalytic process. Fundamentals for optimization of the spatial bed structure, in particular for optimization of the active component distribution through the bed length, are developed intensively with regard to synthesis of new materials and creation of new methods for arranging reaction beds (for example, in microchannel reactors). The authors of the present paper are the first who proposed to use the variational approach for solving these problems, so they theoretically formulated the problem of a catalytic process optimization by means of non-uniform spatial active sites distribution and obtained the analytic solutions for several cases.
In the present paper, the following points are discussed:
1. Setting the optimization problem for a catalytic fixed bed reactor, development of theoretical methods for analysis of the obtained mathematical problem with different reaction rate equations under conditions of intensive heat and mass transfer. Theoretical analysis of the influence of gradient catalysts on:

• Economy of the total active component amount;
• Improvement of the reactant conversion;
• Optimization of the temperature profile;
• Changes in the reaction selectivity.

2. Evaluation of influences of optimal active component distribution on the conversion and selectivity in real processes, in particular in the selective oxidation of methane.

THEORETICAL AND EXPERIMENTAL FUNDAMENTALS FOR OPTIMAL CATALYST BED ARRANGING IN TUBULAR REACTOR

O.P. Klenov, V.M. Khanaev, E.S. Borisova, A.A. Sviridonov, A.S. Noskov

Catal. Ind., Special Issue (2008) pp. 38-46.

The article presents the results of catalyst granular layer structure studying, estimation of its effect on catalytic reactions and demonstrates the practical use of the obtained results for natural gas steam conversion in tubular reactors.
An effect of loading of catalyst particles on the spatial bed structure of a fixed bed of a tubular reactor tube has been proved theoretically and experimentally. An effect of catalyst loading on technological parameters of the process has been shown on the example of commercially important reaction of natural gas steam conversion. In particular, it is shown that optimum loading of a bed can reduce temperature of the external walls of the reactor of steam conversion by some tens of degrees. This ensure longer service of pipes operating at 700-1000^oC. On the basis of the results obtained a loading device was developed and the largest Russian reactors for natural gas steam conversion at M-750 units for methanol production (Tomsk, Gubakha) were loaded.

SPATIALLY RESOLVED NMR THERMOMETRY OF AN OPERATING FIXED-BED CATALYTIC REACTOR

I.V. Koptyug*, A.V. Khomichev*, A.A. Lysova, R.Z. Sagdeev*
(*International Tomography Center, Novosibirsk, Russia)

J. Amer. Chem. Soc., 130(32) (2008) pp. 10452-10453.

An MRI-based approach for the thermometry of an operating packed-bed catalytic reactor was implemented. This approach was employed for the spatially resolved NMR thermometry of the bed of Pd/γ-Al₂O₃ catalyst beads in the course of propylene hydrogenation reaction. This was achieved by detecting the spatially resolved axial 1D profiles of the ²⁷Al NMR signal intensity of Al₂O₃ in the course of the reaction. The experimental results demonstrate a clear correlation between the ²⁷Al NMR signal intensity and the catalyst temperature measured with a thermocouple (25−250°C), and reveal the existence of pronounced temperature gradients along the catalyst bed.

STUDY OF DEEP METHANE OXIDATION KINETICS USING AN IMPROVED FLOW-CIRCULATION METHOD

I.Yu. Pakharukov, N.N. Bobrov, V.N. Parmon

Catal. Ind., 6 (2008) pp. 11-16.

A flow-circulation method appreciably improved in recent years is the most correct method to study stationary kinetics features of heterogeneous reactions. The improvements consist in providing the possibility to determine reaction rate at given composition of a contact reaction mixture (catalytic activity) directly. The improved flow-circulation method was used for the first time to study the process of methane deep oxidation by molecular oxygen with the purpose to obtain one-parametrical dependences of catalytic activity against temperature and reaction medium component concentration as well as to solve an inverse kinetic problem. Catalyst IC-12-72 with composition 16±2 mass % of Sr2O3, 4±0.6 mass % of MgO (the rest - Al₂O₃) was studied. Apparent activation energy of reaction (110 kJ/mol) was determined in kinetic area. An equation well describing experimental data in the given range of concentrations (relative mean deviation was 8%) was formulated based on the experiments and conception of the mechanism of Langmuir-Hinshelwood competitive adsorption reaction. Simplicity of realization of the improved flow-circulation method allows recommending it for selection the most active catalysts and analysis of the dependences of stationary rates of heterogeneous catalytic reactions against various process parameters.

OXIDATION OF ORGANIC COMPOUNDS IN A MICROSTRUCTURED CATALYTIC REACTOR

I.Z. Ismagilov, E.M. Michurin, O.B. Sukhova, L.T. Tsykoza, E.V. Matus, M.A. Kerzhentsev, Z.R. Ismagilov, A.N. Zagoruiko, E.V. Rebrov*, M.H.J.M. de Croon*, J.C. Schouten*
(*Eindhoven University of Technology, Eindhoven, The Netherlands)

Chem. Eng. J., 135(1) (2008) pp. S57-S65.

A microstructured catalytic reactor for the oxidation of organic compounds has been fabricated from aluminum alloy AlMgSiCu1 (6082 series, Al51st). The catalyst section was assembled of 63 microstructured plates with catalytic coating. In each plate of 416 μm thickness, 45 semicylindrical microchannels of 208 μm in radius with a distance in between of 150 μm were electrodischarge machined. A porous alumina layer of 29±1 μm thickness was produced on the plates by anodic oxidation. The resulting coatings were impregnated with an aqueous solution of copper dichromate followed by drying and calcination at 450^oC to produce active catalysts. Kinetics of deep oxidation of organic compounds n-butane, ethanol, and isopropanol was studied in the reactor at 150–360^oC and of 1,1 dimethylhydrazine (unsymmetrical dimethylhydrazine, UDMH) at 200– 375^oC. Intermediate reaction products in the reactions of alcohols and UDMH oxidation were identified. For UDMH, these are methane, dimethylamine, formaldehyde 1,1-dimethylhydrazone, and 1,2-dimethyldiazene. Nitrogen atoms from the UDMH and N-containing intermediates were shown to convert mainly to N2. Kinetic parameters of the reactions of n-butane and alcohols (rate constants and apparent activation energies) were calculated using kinetic modeling based on a modified method of quickest descent.

DEVELOPMENT AND TESTING OF GRANULAR CATALYSTS FOR COMBUSTORS OF REGENERATIVE GAS TURBINE PLANTS

Z.R. Ismagilov, N.V. Shikina, S.A. Yashnik, A.N. Zagoruiko, S.R. Khairulin, M.A. Kerzhentsev, V.N. Korotkikh, V.N. Parmon, B.I. Brainin*, V.M. Zakharov*, O.N. Favorsky*
(*Central Institute of Aviation Motors, Moscow, Russia)

Kinet. Catal., 49(6) (2008) pp. 873-885.

Two types of granular catalysts for effective methane combustion in combustors of gas turbine plants (GTPs) were developed: (1) catalysts based on noble metals with a low Pd content (1–2 wt %), characterized by a low methane ignition temperature, and (2) catalysts based on manganese oxides and hexaaluminates, which have an increased thermal stability. The methane oxidation kinetics was investigated, and combustion in the catalyst chamber of the GTP was simulated. For optimizing the combustion technology, the following two-step process using a combined catalytic package is suggested. The inlet zone of the combustor is filled with a highly active Pd catalyst, which initiates methane oxidation and ensures that the temperature at the exit of this zone is the initial temperature of methane combustion. This takes place in the next zone, which is filled with an oxide catalyst tolerant to high temperatures. The pilot testing of the catalysts was carried out in a model catalytic combustor. The results are in satisfactory agreement with calculated data. Long-term tests indicate the high stability of the catalysts. The Pd catalyst was demonstrated to retain its high activity and to provide an ignition temperature of 240^oC. The initial activity of the hexaaluminatebased catalysts remains unchanged after tests at 930^oC. The use of a combined charge of the palladium (7–15%) and manganese (85–93%) catalysts in the model GTP combustor allows a high natural gas combustion efficiency to be achieved at a low level of hazardous emissions (NOx, 0–1 ppm; CO, 1–3 ppm; hydrocarbons, 3–10 ppm).

CATALYTIC PROCESSES AND CATALYSTS FOR ELEMENTAL SULFUR PRODUCTION FROM SULFUR-CONTAINING GASES

A.N. Zagoruiko, V.V. Shinkarev, S.V. Vanag, G.A. Bukhtiyarova

Catal. Ind., Special Issue (2008) pp. 52-62.

The article presents an analytical review of modern technologies for elemental sulfur production from gases.
Along with wide application of the conventional alumina catalyst in conventional Claus process some new trends which may significantly affect technology of gaseous sulfur production are formulated and generalized: active development of Claus tail gases cleanup process with the stress on replacement of low-temperature processes of “Sulfreen” type with the processes of selective hydrogen sulfide oxidation by oxygen; development of novel highly-efficient technologies for hydrogen sulfide decomposition to sulfur and hydrogen; application of new catalyst types (first of all, on microfiber supports) for Claus and selective H₂S oxidation processes; wider application of titania and vanadia catalysts at new constructed units; development of technologies and catalysts for selective hydrogen disulfide oxidation for direct purification of H₂S-containing gases and for catalytic reduction of SO₂ for sulfur recovery from smelter gases.

DEVELOPMENT OF NEW CATALYSTS AND IMPROVEMENT OF CATALYTIC METHODS OF PURIFICATION OF FUEL GASES FROM VANYUKOV AND FLASH SMELTING FURNACES

Z.R. Ismagilov, S.R. Khairulin, S.A. Yashnik, I.V. Il’yukhin*, V.N. Parmon
(*Zapolyarny affiliate of “Norilsk Nickel” Mining, Russia)

Catal. Ind., Special Issue (2008) pp. 80-85.

Two types of structured catalysts were developed and studied: 1) thermal conductive composite plates (TCP) for one-stage WGSR, and 2) permeable composite materials (PCM) for preferential CO methanation in hydrogen-containing gas in the presence of CO₂ (up to 20 vol %). TCP based on a thermally stable Cu-containing catalyst have high thermal conductivity – up to 2.5-5.0 W/(m^xK); catalyst grain use rate for the TPC is higher than in granules of traditional commercial Cu-containing catalysts. It is shown that in one-stage process with TCP use the CO content can be reduced from 12 to 0.9-1 vol % at gas feed rate of 6300-6900 h^-1 and temperature change along a catalyst bed from 380 to 250^oC. PCM based on Ni-Cr-oxide catalyst has high mechanical strength and thermal conductivity as high as 5?10 W/(m^xK); provides CO content less than 2^x10^-3 % at 200-220^oC and producer gas flows from 6000 to 17000 h^-1, preference to CO hydrogenation is above 0.5; as a result of CO hydrogenation less than 50 % of CH₄ are produced from CO.
For purification of 1 m³ of hydrogen-containing gas from 11-12 vol % to residual CO content less than 2^x10^-4 vol % it is necessary: 1) 0.26 l of a Cu-based catalyst bed in the form of TCP (incl. voids among TPC) for WGSR, and 2) 0.1 l of Ni-based PCM for preferential CO methanation.
Structured catalysts may be used for production of a hydrogen-containing gas for fuel elements. Additionally, they allow carrying out the catalytic processes in conditions of intensive heat- and mass exchange that is especially important for the reactions high selectivity of which is only possible in a narrow temperature interval and in kinetic area.

ANALYSIS OF THE ACTIVITY OF AN ALUMINUM OXIDE CLAUS CATALYST IN COMMERCIAL OPERATION

O.I. Platonov*, L.Sh. Tsemekhman*, P.N. Kalinkin, O.N. Kovalenko
(*Gipronikel’ Institute Limited Liability Company, St. Petersburg, Russia)

2031-2035.Activity dynamics of an AO-MK-2 aluminum oxide catalyst in conversion of hydrogen sulfide and carbonyl sulfide during four years of service in an industrial Claus reactor was analyzed. The rate constants of the Claus reaction were determined and changes in the active surface area of the catalyst were examined.

CLAUS CATALYST ACTIVITY CONTROL IN SULPHUR RECOVERY UNITS

O.I. Platonov*, L.Sh. Tsemekhman*, P.N. Kalinkin, O.N. Kovalenko, M.V. Babkin**
(*Gipronikel’ Institute Limited Liability Company, St. Petersburg, Russia; **JSC “Novomichurinsk Catalyst Plant”, Novomichurinsk, Russia)

Catal. Ind., 6 (2008) pp. 30-34.

The work states methodical principles of catalyst activity control in Claus reactors based on determination of a constant of hydrogen sulfide conversion reaction rate at temperatures of the catalyst less than 280°N. The considered methods have been proved by the data of laboratory researches (in a concentration range of [H₂S]₀ = 1.5-7 vol %), pilot tests ([H₂S]₀ = 0.8-37.4 vol %) of an alumina catalyst of AO-NKZ-2 produced at JSC “Novomichurinsk Catalyst Plant” and the results of its approbation in the Claus reactor of the coke-oven gas treating plant at OJSC “Magnitogorsk Iron and Steel Works”. It is recommended to use them for authentic control of current activity and forecasting of a residual resource of catalysts in commercial Claus reactors operating in conditions of considerable variations of process gas composition as well as for comparative assessment of catalysts activity in Claus process.

BIOETHANOL AS A PROMISING FUEL FOR FUEL CELL POWER PLANTS

V.A. Kirillov, V.D. Meshcheryakov, V.A. Sobyanin, V.D. Belyaev, Yu.I. Amosov, N.A. Kuzin, A.S. Bobrin

Theor. Found. Chem. Eng., 42(1) (2008) pp. 1-11.

The catalytic reaction of steam reforming of bioethanol for the production of a hydrogen-containing gas in a temperature range from 300 to 700°C is studied. Copper-, nickel-, cobalt-, platinum-, and rhodium-containing catalysts supported on different substrates, including metal grids, are tested. Comparative analysis of the methods of bioethanol processing to a hydrogen-enriched gas for feeding high-temperature proton-exchange polymer electrolyte membrane fuel cells is performed.

HYDROGEN PRODUCTION FROM DIMETHYL ETHER AND BIOETHANOL FOR FUEL CELL APPLICATIONS

S.D. Badmaev, P.V. Snytnikov

Int. J. Hydrogen Energy, 33(12) (2008) pp. 3026-3030.

Dimethyl ether (DME) and water-ethanol mixtures are promising and attractive sources of hydrogen for fuel cell applications. Copper-cerium oxide systems have been studied as the catalysts for DME steam reforming to hydrogen-rich gas mixtures. Hydrogen and carbon dioxide were the main reaction products, CO content was insignificant. For CO removal to 10 ppm – the level tolerated by low-temperature fuel cells in the hydrogen-rich feed gas, the reaction of preferential CO methanation in the presence of CO₂ has been used. Nickel-cerium oxide system was used as the catalyst. Steam reforming of water-ethanol mixtures was performed using supported Rh catalyst. Reaction products of ethanol steam reforming at 400°C contained H₂, CH₄ and CO₂. As the temperature increased to 600-700°C, the CH₄ concentration decreased considerably. The obtained hydrogen-rich gas mixture can be used as a feed for high-temperature solid-oxide fuel cells.

CATALYTIC PRODUCTION OF HYDROGEN FROM METHANOL FOR MOBILE, STATIONARY AND PORTABLE FUEL-CELL POWER PLANTS

B.N. Lukyanov

Russ. Chem. Rev., 77(11) (2008) pp. 995-1016.

Main catalytic processes for hydrogen production from methanol are considered. Various schemes of fuel processors for hydrogen production in stationary, mobile and portable power plants based on fuel cells are analysed. The attention is focused on the design of catalytic reactors of fuel processors and on the state-of-the-art in the design of catalysts for methanol conversion, carbon monoxide steam conversion and carbon monoxide selective oxidation. Prospects for the use of methanol in on-board fuel processors are discussed.

MICROCHANNEL CATALYTIC SYSTEMS FOR HYDROGEN ENERGETICS

L.L. Makarshin, V.N. Parmon

Russ. J. General Chem., 77(4) (2007) pp. 676–684.

The concept of hydrogen energetics envisages economically reasonable hydrogen production from various organic compounds in stationary and mobile devices of low and medium performance, called fuel processors. Fuel processors with a high specific performance in hydrogen can be developed with the aid of microchannel catalytic systems. The paper considers the present situation with microchannel catalytic reactors for fuel processors.

DEVELOPMENT OF HIGH-EFFICIENT COMPACT FUEL PROCESSOR WITH MICROCHANNEL REFORMER

A.V. Gulevich*, A.V. Desyatov**, I.M. Izvolsky**, L.L. Makarshin, Y.N. Mamontov**, V.N. Parmon, V.V. Privezentsev*, V.A. Sadykov, A.M. Zlotsovsky**
(*FSUE “SSC RF Institute for Physics and Power Engineering”, Obninsk, Russia; **FSUE “Keldysh Center”, Moscow, Russia)

In “Advanced Energy Technologies for the Earth and Outer Space”, Eds. A.S. Koroteeva,

M: ZAO “Svetlitsa”, 2008, 208 pp.

According to the order of the National Innovation Company “New Energy Projects” a partial methane oxidation fuel processor has been developed and tested, which generates synthesis gas in amounts necessary to provide power source of a high temperature fuel cell battery of electric power of 2 kW. The fuel processor is integrated by heat with the battery using anode gas heat. The fuel processor reformer is manufactured using the microreactor technology. The technological unit incorporates a sulfur cleaning unit providing cleaning of natural gas from hydrogen sulfide to a level of 5 mg/m³ within a half a year in addition to the reformer and heat exchangers. The unit feeding air to the technological unit of the fuel processor incorporates a membrane pump, a filter and a device making it possible to control the air flow rate by the variation of pump current frequency. A control unit has been developed and manufactured for the fuel processor, which enables the operating parameters to be monitored by means of computer. The control unit is able as well to cut off methane and air feed to the fuel processor in the case of emergency situations. Tests as conducted demonstrated the fuel processor serviceability. With nominal fuel flow rate the operating temperature of the fuel processor is at a level of 800– 850°C. The time the reformer needs to attain 850°C at startup is 30–40 min. Depending on the fuel flow rate and methane-air proportion the temperature of the reformer and synthesis gas can be below or above the above mentioned value. The analysis results on reformate composition at the fuel processor exit indicate that the methane conversion at Reformer temperatures of 850–900°N, when the catalyst activity is high, is equal to 95%. Yield in terms of hydrogen and carbon oxide is close to the calculational indices. As temperature decreases, the catalyst activity drops and, consequently, the methane conversion decreases. At present the fuel processor is being tested for its performance and lifetime in “Keldysh Center”. Tests are being conducted according to the NIC”NEP” program. The created specimen may serve as a basis for the development of the fuel processor for a high capacity power unit.

HYDROGEN PRODUCTION BASED ON THE SELECTIVE CATALYTIC PYROLYSIS OF PROPANE

E.A. Solov’ev*, D.G. Kuvshinov**, I.S. Chukanov*, D.Yu. Ermakov, G.G. Kuvshinov*
(*Novosibirsk State Technical University, Novosibirsk, Russia; **Queen’s University Belfast, Belfast, Northern Ireland, UK)

Theor. Found. Chem. Eng., 42(5) (2008) pp. 611-621.

Catalytic decomposition of propane with producing hydrogen in a temperature range of 400– 700°C is investigated. Optimal production parameters (temperature, catalyst composition), which provide the production of a mixture of hydrogen and propane with a low methane content free of carbon oxides for a long time, are established.

DIRECT CONVERSION OF METHANE ON Mo/ZSM-5 CATALYSTS TO PRODUCE BENZENE AND HYDROGEN: ACHIEVEMENTS AND PERSPECTIVES

Z.R. Ismagilov, E.V. Matus, L.T. Tsykoza

Energy Environ. Sci., 1 (2008) pp. 526-541.

Development of highly effective catalysts for one-stage conversion of light hydrocarbons with high selectivity to valuable products will solve such problems as efficient utilization of natural and oil-associated gases, and environmental protection. Methane dehydroaromatization (DHA) over Mo/ZSM-5 catalysts is a promising process for direct production of valuable aromatic compounds and hydrogen from methane. This review focuses on the range of issues dealing with the effect of catalyst composition, preparation, pretreatment and operation conditions on the physicochemical properties and activities of Mo/ZSM-5 catalysts in DHA reaction. The concepts of the reaction mechanism and the nature of the active molybdenum forms are reviewed. Various aspects of the Mo/ZSM-5 deactivation under reaction conditions and methods of their regeneration are discussed. Some approaches for improvement of the Mo/ZSM-5 performance in DHA reaction are addressed in the review in detail.

LiCoO₂-BASED CATALYSTS FOR GENERATION OF HYDROGEN GAS FROM SODIUM BOROHYDRIDE SOLUTIONS

O.V. Komova, V.I. Simagina, O.V. Netskina, D.G. Kellerman*, A.V. Ischenko, N.A. Rudina
(*Institute of Solid State Chemistry, Yekaterinburg, Russia)

Catal. Today, 138(3-4) (2008) pp. 260-265.

The catalytic performance of lithium cobaltite, LiCoO₂, in sodium borohydride hydrolysis has been studied and compared with catalytic properties of Co₃O₄, CoCl₂ and Co(NO₃) ₂. Activation times and observed H₂ generation rates were found dependent on the chemical nature and dispersion of the catalysts, as well as on the reaction temperature. The magnetic susceptibility method was used to demonstrate that all studied cobalt compounds, including cobalt oxides and soluble salts, are being reduced under catalytic conditions to form catalytically active cobalt boride phases. Impregnating LiCoO₂ with Pt and Rh chlorides increases only the initial catalytic activity, which then quickly declines during cyclic stability tests and in just a few cycles approaches that of the starting LiCoO₂ material.

HYDROGEN PRODUCTION BY CATALYTIC HYDROCARBON DECOMPOSITION VIA CARBIDE CYCLE MECHANISM

V.V. Chesnokov, R.A. Buyanov, V.V. Molchanov

Catal. Ind., Special Issue (2008) pp. 19-23.

Method of hydrogen production by catalytic decomposition of hydrocarbons via carbide cycle mechanism is considered. The reasons of generation of methane in equilibrium concentration as an admixture to hydrogen are explained. A catalyst with productivity up to 600 l of hydrogen per 1 g of the catalyst during 1 cycle at maximum possible temperature (700-750^oC) was developed to reduce the depending on the temperature methane equilibrium concentration. A method was suggested for catalyst regeneration using water steam with possibility of its cycle operation.

SORPTION ENHANCED HYDROCARBONS REFORMING FOR FUEL CELL POWERED GENERATORS

A.I. Lysikov, S.N. Trukhan, A.G. Okunev

Int. J. Hydrogen Energy, 33(12) (2008) pp. 3061-3066.

The single-step sorption enhanced reforming of methane, propane–butane mixture, ethanol, methanol over an admixture of CaO sorbent with a Ni reforming catalyst have been experimentally studied in a periodically operated quasi-adiabatic fixed bed reactor. The bed temperature profile during reforming step drastically influences the purity of product hydrogen. The best results were obtained for the temperature decrease downstream the reactant flow. In the case of the alcohols reforming the hydrogen purity was 98–99 vol % with both CO and CO₂ impurities of about 10–20 ppm. A proton exchange membrane fuel cells (PEMFC) stack was successfully fed with the hydrogen produced by the single-step sorption enhanced reforming of ethanol without any loss of efficiency. Both the sorbent and the catalyst maintained sufficient activity level during 1500 h on stream and more than 600 cycles.

DEVELOPMENT OF Cu- AND Ni-CONTAINING STRUCTURED CATALYSTS FOR PURIFICATION OF H₂-RICH GASES FROM CARBON MONOXIDE BY STEAM CONVERSION AND PREFERENTIAL HYDROGENATION

T.P. Minyukova, N.A. Baronskaya, A.A. Khassin, T.M. Yurieva

Catal. Ind., Special Issue (2008) pp. 24-30.

Two types of structured catalysts were developed and studied: 1) thermal conductive catalyst plates (TCP) for one-stage WGCR and 2) permeable composite material (PCM) for reaction of preferential CO methanation in hydrogen rich gas in CO2 excess (up to 20 vol %). TCP based on a thermally stable Cucontaining catalyst possesses high thermal conductivity - up to 2.5-5.0 W(m^xK); catalyst grain use for TCP is higher than in the granules of traditional commercial Cu-containing catalysts. It is shown that in one-stage process with TCP CO concentration can be reduced from 12 to 0.9-1 vol % at the gas feed rate of 6300-6900 h^-1 and temperature change along the catalyst bed from 380 to 250^oC. PCM based on a Ni-Cr-oxide catalyst has high mechanical strength; thermal conductivity as high as 5?10 W/(m^xK); provides CO residual content less than 2x10^-1 % at 200-220^oC and gas flow 6000?17000 h^-1; CO preference hydrogenation above 0.5; CO₂ hydrogenation results in no more than 50% of CH₄. For purification of 1 m³ of hydrogen containing gas from 11-12 vol % to residual CO content less than 2x10^-4 it is necessary: 0.26 l of Cu-based TCP (including voids among TCPs) and 2) 0.1 l of Ni-based PCM for preferential CO methanation.
Structured catalysts may be used for production of hydrogen-containing gas for fuel cells. Additionally, they allow carrying out the catalytic processes in conditions of intensive heat- and mass exchange that is especially important for reactions which are selective only in narrow temperature interval and in kinetic area.

PREFERENTIAL CO OXIDATION OVER A COPPER–CERIUM OXIDE CATALYST IN A MICROCHANNEL REACTOR

P.V. Snytnikov, M.M. Popova, Y. Men*, E.V. Rebrov**, G. Kolb*, V. Hessel*^,**, J.C. Schouten**, V.A. Sobyanin
(*Institut fur Mikrotechnik Mainz GmbH, Mainz, Germany; **Eindhoven University of Technology, Eindhoven, The Netherlands)

Appl. Catal., A, 350(1) (2008) pp. 53-62.

The activity of a 5 wt % Cu/CeO2-x catalyst during preferential CO oxidation in hydrogen-rich gas mixtures was studied in a microchannel reactor. The CO concentration dropped from 1 vol % to 10 ppm at a selectivity of 60%, at a temperature of 190^oC, and a WHSV of 55,000 cm³g^-1h^-1. Both the CO concentration and the temperature increased when the WHSV was increased from 50,000 to 500,000 cm³g^-1h^-1. An increase of the O2 concentration from a 1.2 to 3 fold excess reduced the CO concentration to 10 ppm in a broad temperature interval of 50°C at WHSVs up to 275,000 cm³g^-1h^-1. The preferential CO oxidation could be carried out at higher flow rates and at higher selectivities in the microchannel reactor compared to a fixed-bed flow reactor.

COMPARATIVE STUDY ON CONVERSION OF C₈ AND C₁₆ PARAFFINS ON ZSM-5 CATALYSTS

D.G. Aksenov, O.V. Kikhtyanin, G.V. Echevsky

Stud. Surf. Sci. Catal., 174A (2008) pp. 1211-1214.

A comparative study of conversion of n-octane and n-hexadecane in conditions of BIMF process was performed to follow reaction pathways and to estimate advantages to use heavier distillates for obtaining high-quality fuels. It was found that the conversion of both n-octane and n-hexadecane depends on reaction pressure, and the yield of liquid reaction products is higher in the case of heavier feed. However products of n-octane conversion demonstrate more stable behavior with TOS (Time On Stream). Benzene content is lower in the case of n-hexadecane. A positive effect of heavier hydrocarbons in minimizing dealkylated aromatics content was demonstrated by special experiments.

DEVELOPMENT OF CATALYST Pt-SAPO-31 FOR HEAVY HYDROCARBON FRACTION HYDROISOMERIZATION PROCESSES

O.V. Kikhtyanin, G.V. Echevsky

Catal. Ind., 3 (2008) pp. 47-53.

Catalyst Pt-SAPO-31 was obtained on the basis of synthesized silicoaluminophosphate with the structure of SAPO-31 and applied for hydroisomerization of heavy hydrocarbon fractions. Activity and selectivity of the catalyst of various chemical compositions in conversion of n-octane, diesel fraction and slack wax were investigated. Optimum structure of the catalyst has been revealed. Pt-SAPO-31 catalyst considerably reduces turbidity and freezing temperatures of reaction products by reducing content of n-paraffins, not being inferior by these parameters to an industrial catalyst on the basis of silicoaluminophosphate SAPO-11 in production of low cold-test diesel and oil fractions. Presence in raw materials of sulfur up to 500 ppm reduces activity of the catalyst and requires rise of reaction temperature by 1015^oC for production of products with necessary temperature characteristics. Laboratory tests were a basis for carrying out catalyst pilot tests.

SYNTHESIS OF SAPO-31 WITH di-n-PENTYLAMINE: INFLUENCE OF CHEMICAL COMPOSITION AND CRYSTALLIZATION CONDITIONS

O.V. Kikhtyanin, A.V. Toktarev, A.B. Ayupov, G.V. Echevsky

Stud. Surf. Sci. Catal., 174B (2008) pp. 245-248.

SAPO-31 materials were prepared using di-n-pentylamine. Both composition of reaction mixture and hydrothermal treatment conditions exhibit an influence on the crystallization kinetics. Thus, low silica content accelerates crystallization, however high silica content has an opposite effect. Calculation of unit cell parameters for samples with different crystallinities may help in understanding of crystallization mechanism. The obtained results are discussed using data of physico-chemical methods.

PILOT TESTS OF Pt-SAPO-31 CATALYST IN GASOIL ISOMERIZATION

O.V. Kikhtyanin, A.V. Toktarev, G.V. Echevsky, I.D. Resnichenko*
(*Angarsk Catalyst and Organic Synthesis Plant Co., Angarsk, Russia)

Catal. Ind., Special Issue (2008) pp. 30-38.

The article presents the results of pilot tests of a pre-production prototype of catalyst Pt-SAPO-31, mass. % Pt – (0.5-1), Al₂O₃ – 46, P₂O₅ – 38, SiO₂ – 16, completely confirmed results of earlier laboratory studies of this material in hydroisomerization of heavy hydrocarbon fractions. The purpose of the tests was: selection of an optimal regime for isomerization of gasoils with various sulfur content; determination of product properties according to requirements of standards; estimation of catalyst operation stability. It is shown that the catalyst is highly active and selective in conversion of initial gasoil. It is proved by decreasing of freezing and cloud point temperature by 30-35^oC at diesel fuel output 96-98%. Resource tests of the catalyst in processing of raw material with sulfur content 5x10^-3 % at 335-340^oC showed high stability of its operation during 800 hours without change of catalytic activity and temperature characteristics of the product. Pilot tests showed advantages of the preproduction prototype Pt-SAPO-31 and prospects of its practical use in hydroisomerization of gasoils with sulfur content up to 35x10^-2 %. Properties of the end products are defined by a temperature regime of the process. Large-scale technology is developed. Organization of industrial production of the catalysts is possible at existing catalyst plants having experience of zeolite synthesis.

HYDROTREATMENT OF DIESEL FEEDSTOCK OVER Pt-SAPO-31 CATALYST: FROM LAB TO PILOT SCALE

O.V. Kikhtyanin, L.A. Vostrikova, G.A. Urzhuntsev, A.V. Toktarev, M.I. Tselyutina*, I.D. Reznichenko*, G.V. Echevsky
(*Angarsk Catalyst and Organic Synthesis Plant Co., Angarsk, Russia)

Stud. Surf. Sci. Catal., 174B (2008) pp. 1227-1230.

High effective hydroisomerization properties of Pt-SAPO-31 catalyst were demonstrated both in laboratory experiments and on pilot scale. Activity of the catalyst is suppressed by sulfur (100-500 ppm), but it may be restored by temperature rise. Long-term run of Pt-SAPO-31 catalyst have confirmed its high activity and stability. Group compositions of feedstock and reaction products were examined by ¹H and ¹³C NMR method and properties of the catalyst in dependence on reaction properties are discussed.

INFLUENCE OF THE HEAT TREATMENT CONDITIONS ON THE ACTIVITY OF THE CoMo/Al2O3 CATALYST FOR DEEP HYDRODESULFURIZATION OF DIESEL FRACTIONS

A.V. Pashigreva, G.A. Bukhtiyarova, O.V. Klimov, G.S. Litvak, A.S. Noskov

Kinet. Catal., 49(6) (2008) pp. 812-820.

The effect of the heat treatment temperature on the sulfidation and activity of CoMo/Al₂O₃ catalysts designed for deep hydrodesulfurization of diesel fuel was studied. The catalysts were prepared using citric acid as a chelating ligand. The organic ligands present in the samples heat-treated at 110 and 220^oC retard the decomposition of dimethyl disulfide and the formation of the sulfide phase but make the catalyst more active than the samples calcined at higher temperatures.

MODERN CATALYSTS FOR DEEP HYDROTREATING FOR PRODUCTION OF LOW-SULFUR DIESEL FUELS BY EURO-3 AND EURO-4 STANDARDS AT THE RUSSIAN PETROLEUM PROCESSING PLANTS

O.V. Klimov, A.V. Pashigreva, G.A. Bukhtiyarova, V.N. Kashkin, A.S. Noskov, Ya.M. Polunkin*
(*JSC “TNK-VR Menedzhment, Moscow, Russia)

Catal. Ind., Special Issue (2008) pp. 6-13.

For production of diesel fuels with sulfur content according to Euro-3 and Euro-4 standards at the Russian petroleum processing plants without reconstruction of existing hydrotreating units it is necessary to replace catalysts by more active ones. Most of the Russian catalysts can be used for production of diesel fuels with sulfur content 3.5x10^-2 mass. %, or higher. For production of fuel with sulfur content less than 5.0^x10^-3, and residual sulfur content less than 1.0^x10^-3 mass. %, it is necessary to use catalysts of the latest generation, surface compounds of which represent a highly active Co(Ni)-Mo-S phase of the second type. Domestic catalyst IC-GO-1 that has been produced at the CJSC “Promyshlennye Katalizatory” since 2007 under the license of the Boreskov Institute of Catalysis is a typical representative of such catalysts. Upon commercial operation of the catalyst at the JSC “Saratovskii NPZ” hydrotreating parameters guaranteed both by the developer and the manufacturer were confirmed. Production of IC-GO-1 can reach 600 t/year that is enough for re-equipment of 10 typical Russian hydrotreating plants within a year.

FINE HYDROTREATMENT OF OIL DISTILLATES OF PRIMARY AND SECONDARY ORIGIN OVER NEW GENERATION CATALYSTS

A.V. Pashigreva, G.A. Bukhtiyarova, O.V. Klimov, A.S. Noskov, Ya.M. Polunkin*
(*JSC “TNK-VR Menedzhment, Moscow, Russia)

Neftepererabotka i Neftekhimiya, 10 (2007) pp. 19-23.

The possibility of synthesis of high-quality low-sulfur diesel fuels from straight-run oil distillate and from the mixture of the straight-run distillate with gasoil of the catalytic cracking was studied in the presence of new generation Co-Mo/Al₂O₂ sulfide catalysts. Catalytic properties of these catalysts and of a number of the best Russian and imported catalysts were compared. It was shown that the hydrotreatment process, when achieved over the new-generation catalysts under conditions typical of the Russian refineries, allows the EURO-4 diesel fuel to be produced from the straight-run oilfeed. When the feed is a mixture containing 30% of the catalytic cracking gasoil, the properties of the resulting hydrogenizates are somewhat out the EURO-4 standards. The obtained data on the transformations of organosulfur and condensed aromatic compounds lead to expect the stable yield of diesel fuels satisfying the EURO-4 standards at a decreased proportion of catalytic cracking gasoil in the feed.

PRECIOUS METALS FOR CATALYST PRODUCTION

V.N. Parmon, V.I. Simagina, L.P. Milova

Catal. Ind., Special Issue (2008) pp. 46-52.

Application of precious metals (platinum and palladium) for catalyst production taking into account creation and development of new catalytic technologies is reviewed. Production of domestic catalysts on the basis of precious metals is reduced. Annual production of these catalysts is a little more than 300 t which corresponds to approximately 25-30% use of existing capacities for production of these catalysts. Construction of new and modernization of existing plants that use catalysts containing precious metals is carried out with the participation of foreign companies. The share of imported catalysts containing Pd and Pt for various process still remains significant (up to 60%). The level of precious metals consumption in production of organic synthesis products and medical products remains at the level of 1990s. Potentialities of extended applications of platinoids are reviewed both for creation of new generations of traditional catalysts in petroleum processing, petroleum chemistry, organic synthesis, protection of environment competitive with import ones and for areas new for Russia such as creation of nanocomposite materials for hydrogen power engineering, medical products, membrane technologies.

UNIVERSAL RELATION BETWEEN THE BOUNDARY TEMPERATURES OF A BASIC CYCLE OF SORPTION HEAT MACHINES

Yu.I. Aristov, M.M. Tokarev, V.E. Sharonov

Chem. Eng. Sci., 63(11) (2008) pp. 2907-2912.

For analyzing a basic cycle of an adsorption heat machine (AHM) an empiric rule was suggested, which manifests that adsorption isosters and equilibrium line lnP(1/T) for the pure sorbate intersect at T approaching infinity. This rule prompts how to plot the cycle, gives a link between the boundary temperatures of the cycle and allows estimation of a minimal temperature T^min σ of an external heat source that is necessary to drive the cycle. In this paper the validity of the T^min σ estimation was justified for working pairs which are most commonly used for adsorption units: water-silica gel, water-zeolite 13X, water-zeolite 4A, water-selective water sorbents (SWSs), CO₂-carbon, methanol-carbons (AC-35, TA90), methanol-hydrophobic zeolite CBV 901 Y and ammonia-carbon PX31. Four main working pairs for absorption heat machines-ammonia-water, water-LiBr, methanol-LiBr and R22-isobutylacetate are also analyzed. This allowed the formulation of requirements to an optimal adsorbent to be used in a single-effect non-regenerative cycle of an AHM. The accuracy of the T^min σ estimation was examined for each pair. Moreover, it was shown that Trouton's rule is always valid if sorption equilibrium obeys the Polanyi potential theory, i.e., the equilibrium sorption is a unique function of the sorption potential AF = -RT ln(P/P0). For chemical reactions between various salts and sorbates this rule is violated because of a large difference between the standard changes of the entropy and enthalpy in the course of reaction and evaporation. In this case T^min σ can be calculated from the Clausius-Clapeyron and Vant-Hoff equations.

HYBRID AUTOWAVES IN FILTRATION COMBUSTION OF GASES IN A CATALYTIC FIXED BED

A.P. Gerasev

Combust., Explosion, Shock Waves, 44(2) (2008) pp. 123-132.

A mathematical model of autowave processes in a heterogeneous medium with chemical reactions in the gas phase and on the catalyst is constructed. The coefficients of heat and mass transfer between the phases and the thermal conductivity of the solid phase are determined from the current values of system parameters. The model describes three types of autowaves: waves due to filtration combustion of gases in the low-velocity regime, waves due to a catalytic reaction, and hybrid waves. The behavior of phase trajectories of the dynamic system is studied by methods of qualitative and numerical analysis, and an effective technique is developed for searching for a physically grounded autowave solution of the problem. The laws of propagation of autowaves due to filtration combustion of gases and hybrid autowaves are numerically examined, and the effect of system parameters on the basic technological characteristics of autowave processes is studied.

MATHEMATICAL MODELING OF THE CONTINUOUS PROCESS FOR SYNTHESIS OF NANOFIBROUS CARBON IN A MOVING CATALYST BED REACTOR WITH RECIRCULATING GAS FLOW

S.G. Zavarukhin, G.G. Kuvshinov*
(*Novosibirsk State Technical University, Novosibirsk, Russia)

Chem. Eng. J., 137(3) (2008) pp. 681-685.

A continuous process for synthesis of nanofibrous carbon from methane in a reactor with a moving bed of the Ni-Al2O3 catalyst (90 wt % Ni) and intensively recirculated gas flow is considered. Dependencies for calculating outlet characteristics of the gas mixture and catalyst are suggested. Comparison of various types of continuous reactors shows that the suggested reactor is preferable.

MODELING OF CONTROLLED COMBUSTION OF HIGH-ENERGETIC MATERIALS ON STRUCTURED CATALYSTS

V.M. Khanaev, E.S. Borisova, N.N. Kundo

Combust., Explosion, Shock Waves, 44(5) (2008) pp. 535-542.

A mathematical model of combustion of high-energetic materials on structured catalysts is developed. Numerical studies are performed for combustion of a typical material: aminoguanidine nitrate. An increase in catalytic activity, as well as an increase in the thermal conductivity of the catalyst, is found to expand the range of real-time controlling of the burning rate of the condensed substance.

NUMERICAL STUDY OF A MATHEMATICAL MODEL OF A CATALYTIC FUEL PROCESSOR WITH COCURRENT OXIDATION AND CONVERSION FLOWS

S.I. Fadeev*, A.B. Shigarov, V.A. Kirillov, N.A. Kuzin
(*Sobolev Institute of Mathematics, Novosibirsk, Russia)

J. Appl. Ind. Math., 2(3) (2008) pp. 329-340.

The results are presented of the numerical study of a mathematical model in the form of a nonlinear boundary value problem describing the stationary regimes in a catalytic fuel processor. The authors study a two-dimensional model for the endoblock, with the longitudinal heat and mass transfer by the gas and the transversal heat conductivity along the catalyst in the two-temperature approximation. For the exochannel, a model is considered with the longitudinal heat and mass transfer by the gas flow and the longitudinal heat transfer along the catalytic wall. These two blocks are related to each other through the equality of the temperature and heat flux on the boundary. The results obtained are in good agreement with experimental data.

STOCHASTIC SIMULATION OF PHYSICOCHEMICAL PROCESSES PERFORMANCE OVER SUPPORTED METAL NANOPARTICLES

E.V. Kovalyov, V.I. Elokhin, A.V. Myshlyavtsev*
(*Omsk State Technical University, Omsk, Russia)

J. Comput. Chem., 29(1) (2008) pp. 79-86.

The statistical lattice model has been proposed which permits one to take into account the change in the shape and surface morphology of the nanoparticle under the influence of the reaction media. The influence of monomolecular and dissociative adsorption on the particles equilibrium shape and surface morphology has been studied. It has been shown that by taking into account of attraction “adsorbate-metal” the reshaping of the initial hemispheric particle into cone-shaped one occurs induced by adsorption, similar to the experimentally observed reversible reshaping of active nanoparticles. The model reaction A+B₂ has been studied taking into account the roughening of the active particle surface and the spillover phenomena of the adsorbed Aads species over the support surface.

PRODUCTION OF NANOMATERIALS BY VAPORIZING CERAMIC TARGETS IRRADIATED BY A MODERATE-POWER CONTINUOUS-WAVE CO₂ LASER

V.N. Snytnikov, Vl.N. Snytnikov, D.A. Dubov, V.I. Zaikovsky, A.S. Ivanova, V.O. Stoyanovsky, V.N. Parmon

J. Appl. Mech. Techn. Phys., 48(2) (2007) pp. 292-302.

The efficiency of utilization of CO2 laser energy for vaporization of Al₂O₃ ceramics is evaluated using a mathematical model for the interaction of laser radiation with materials. It is shown that the calculated efficiency of radiation-energy utilization is not higher than 15% at a radiation power density of 10⁵ W/cm² on the target. On the experimental facility designed for the synthesis of nanopowders, a vaporization rate of 1 g/h was achieved for Al2O3, which corresponds to a 3% efficiency of radiation-energy utilization. The dependence of the characteristic particle size of a zirconium oxide nanopowder on helium pressure in the range of 0.01–1.00 atm was studied. Results of experiments on vaporization of multicomponent materials (LaNiO3 and the Tsarev meteorite) are given.

THE SPECIAL FEATURES OF PHASE EQUILIBRIA IN α-PINENE-WATER BINARY MIXTURES IN THE SUB-AND SUPERCRITICAL STATES

A. Yermakova, A.M. Chibiryaev*, I.V. Kozhevnikov, P.E. Mikenin, V.I. Anikeev
(*Novosibirsk Institute of Organic Chemistry, Novosibirsk, Russia)

Russ. J. Phys. Chem. A, 82(6) (2008) pp. 928-932.

Phase equilibria in α-pinene–water binary mixtures under sub- and supercritical conditions were studied by thermodynamic modeling. The compositions and boiling points of three-phase heteroazeotropic mixtures were calculated as functions of pressure. The T and p regions of the existence of liquid–liquid and vapor–liquid two-phase mixtures were determined. The T_c mix and p_c mix critical curve coordinates depending on mixture composition were found. The T_c mix curve exhibited an anomaly in the form of a minimum. The T_{Az pAz} heteroazeotropic line ended at the minimum point of the critical curve.

CALCULATION OF PHASE DIAGRAMS OF HETEROPHASE TWO- AND THREE-COMPONENT LIQUID MIXTURES ‘α-PINENE – WATER’ AND ‘α-PINENE – WATER – ETHANOL’

A. Yermakova, A.M. Chibiryaev*, I.V. Kozhevnikov, V.I. Anikeev
(*Novosibirsk Institute of Organic Chemistry, Novosibirsk, Russia)

Chem. Eng. Sci., 63(24) (2008) pp. 5854-5859.

Phase behaviors of two- and three-component mixtures ‘α-pinene–water’ and ‘α-pinene–ethanol– water’ were studied over a wide range of their composition, temperature, and pressure. Conditions were found that provide heteroazeotropic states of binary mixture ‘α-pinene–water’ and ternary mixture ‘α-pinene–ethanol–water’ depending on the ratio of ‘water/(α-pinene+ethanol)’ fractions at the ‘α-pinene+ethanol’ ratio of 1:1. Critical curves were calculated to demonstrate an anomalous dependence of these curves on the mixture composition, with the temperature minimum points typical of the mixtures that form heteroazeotropes.

THE KINETICS OF THERMAL ISOMERIZATION OF β-PINENE AND A MIXTURE OF β- AND α-PINENES IN SUPERCRITICAL ETHANOL

A. Yermakova, A.M. Chibiryaev*, I.V. Kozhevnikov, V.I. Anikeev

J. Supercrit. Fluids, 45(1) (2008) pp. 74-79.

Thermal isomerization of p-pinene and equimolar mixture of α- and β-pinenes in supercritical ethanol was studied experimentally. The reactivity of structurally similar α- and β-pinenes were compared in the same supercritical solvent. It was shown that both pinenes undergo thermal transformations independently of one another upon co-thermolysis in supercritical (SC) ethanol. Conversion of α-pinene yields monocyclic limonene as the main product, and p-pinene gives acyclic p-myrcene. This study allowed developing the first kinetic model of p-pinene thermolysis in SC ethanol.

THE INFLUENCE OF WATER ON THE ISOMERIZATION OF α-PINENE IN A SUPERCRITICAL AQUEOUS-ALCOHOLIC SOLVENT

A. Yermakova, A.M. Chibiryaev*, P.E. Mikenin, O.I. Sal’nikova*, V.I. Anikeev
(*Novosibirsk Institute of Organic Chemistry, Novosibirsk, Russia)

Russ. J. Phys. Chem. A, 82(1) (2008) pp. 62-67.

The influence of water as a cosolvent and catalyst of the isomerization of α-pinene in a supercritical aqueous–alcoholic (ethanol) solvent was studied experimentally. At T=657 K and p = 230 atm, an increase in the concentration of water in the reaction mixture was found to increase the rate of the reaction and its selectivity with respect to the desired product, limonene. Water exhibited the properties of an acid catalyst because of its ionization. Mathematical experimental data processing was performed to evaluate and separate the contributions of the radical and ionic paths to the total rate of the reactions that occurred during the thermal isomerization of α-pinene.

MODELING OF REVERSE-FLOW REACTOR FOR VOC INCINERATION WITH ACCOUNT OF REVERSIBLE ADSORPTION: THE WAY TO MINIMIZE THE NEGATIVE INFLUENCE OF DESORPTION PHENOMENA

A.N. Zagoruiko

Int. J. Chem. Reactor Eng., vol. 6: A110 (2008).

The paper discusses the influence of adsorption/desorption phenomena on the purification performance of the reverse-flow catalytic incinerator for abatement of volatile organic compounds (VOC). It is shown that the reversible adsorption of VOC at the catalyst surface may occur at the catalyst bed inlet in the end of the cycle, followed by desorption into outlet gases after flow reversal leading to decrease of the process purification efficiency. The mathematical modelling results showed that inert material beds in combination with proposed process control strategy are needed to avoid negative influence of adsorption effects.

ANAEROBIC CATALYTIC OXIDATION OF HYDROCARBONS IN MOVING HEAT WAVES. CASE SIMULATION: PROPANE OXIDATIVE DEHYDROGENATION IN A PACKED ADIABATIC V–Ti OXIDE CATALYST BED

A.N. Zagoruiko

Chem. Eng. Sci., 63(20) (2008) pp. 4962–4968.

The model simulation study has shown that the anaerobic process of oxidative dehydrogenation of propane under periodic alteration of feeding between propane and air may be realized in adiabatic catalyst beds in a stable continuous cyclic mode in a two-reactor scheme. In the case of an appropriate choice of process parameters (cycle duration and feeding flow rates) the process appears to be autothermal, i.e. it does not require any inlet gas preheating for stable operation. Compared with a similar steady-state adiabatic process, the proposed process is characterized with much lower maximum catalyst temperatures, giving the way to process pure propane without diluting it with inert gases, thus simplifying the downstream procedure of product separation. Predicted propylene yield is competitive with the one for the steady-state adiabatic process, while sufficient technological benefits of the new technology are expected (decrease in energy consumption and minimization of heat-exchange environment, process safety improvement, suppression of coke formation and efficient coke incineration).

DEVELOPMENT AND APPLICATION OF SOFTWARE FOR THE AGENT MODEL OPTIMIZATION

O.A. Zasypkina, O.P. Stoyanovskaya, I.G. Chernykh

Numer. Methods Program., 9 (2008) pp. 19-25.

A new technology for the model construction of physico-chemical processes of agents is proposed. This technology gives a possibility of searching and adaptation of kinetics scheme for chemical reactions. A new version of the ChemPAK software package is discussed as an application of this technology. The package was used to study the Butlerov reaction scheme and the ethane and methane pyrolysis schemes.

STUDYING INSTABILITY OF 3D COLLISIONLESS SYSTEMS ON STOCHASTIC TRAEJECTORIES

V.N. Snytnikov, E.A. Kuksheva

In “Collective Phenomena in Macroscopic Systems”,
Eds. G. Bertin, R. Pozzolli, World Scientific Pub. Co Inc., 2007, pp. 280-285.

A practical method for distinguishing stochastic and regular subsystems in the entire set of particles for numerical modeling of the development of physical instabilities in collisionless systems with self-consistent fields is proposed. The method of subdividing the phase space into subsystems is based on the comparison of the results of two computational experiments with identical initial conditions but different realizations of rounding errors. An example of establishing the spatial and temporal domains of the development of collective instability and determining the instability increments is offered by a gravitating disk.

A CAPILLARY GAS CHROMATOGRAPHIC COLUMN WITH A POROUS LAYER BASED ON A MESOPOROUS MATERIAL

Yu.V. Patrushev, V.N. Sidelnikov, M.K. Kovalev, M.S. Melgunov

Russ. J. Phys. Chem. A, 82(7) (2008) pp. 1202-1205.

A procedure for synthesizing an MSM-41-type mesoporous mesophase material (MMM) layer, that is, a layer of a solid porous material with a regular arrangement of nanoscale calibrated pores and a unified geometry, on the inner wall of a capillary column was developed. Because of the high specific surface area of silica, capillary columns with a porous MMM layer on the basis of silica allow the amount of samples introduced to be increased by an order of magnitude compared with the known capillary porous-layer columns. An example of the separation of light hydrocarbons is described. The properties of columns with MMM porous layers are discussed.

GAS-CHROMATOGRAPHIC STUDY OF THE RETENTION OF COMPONENTS OF THE REACTION OF THE CATALYTIC OXIDATION OF PROPYLENE ON POROUS POLYMERS

E.Yu. Yakovleva, O.V. Skrypnik

J. Anal. Chem., 63(5) (2008) pp. 455-459.

The gas-chromatographic retention of oxygen, carbon dioxide, propane, propylene, water, propylene oxide, acrolein, acetone, and acetaldehyde on polar and nonpolar adsorbents was studied. A procedure was proposed for the gas-chromatographic determination of gaseous and liquid components of the reaction of the catalytic oxidation of propylene using one column.

A GAS-CHROMATOGRAPHIC STUDY OF THE RETENTION OF REACTION COMPONENTS IN THE CATALYTIC OXIDATION OF β-PICOLINE TO NICOTINIC ACID

E.Yu. Yakovleva, V.Yu. Belotserkovskaya, O.V. Skrypnik

J. Anal. Chem., 63(9) (2008) pp. 863-866.

The gas-chromatographic retention of pyridine, β-picoline, 3-pyridinecarbaldehyde, 3-pyridinenitrile, nicotinic acid, and nicotinamide on polar stationary phases was studied. A scheme was proposed and a procedure was developed for the determination of the reaction components of the catalytic oxidation of β-picoline to nicotinic acid on a column (3 m x 3 mm) packed with Chromosorb WAW + 10 wt % FFAP. The separation time was 28 min. The detection limits were 0.01 and 0.37 ppm for 3-pyridinenitrile and nicotinic acid, respectively.

CONTACT LENSES

V.F. Danilichev*, S.A. Novikov**, N.A. Ushakov*, V.N. Pavlyuchenko*, E.V. Boiko*, M.S. Polyak*, E.V. Muravieva*, I.N, Okolov*, V.A. Reituzov*, G.V. Gorelova*, V.M. Dolgikh*, S.Ya. Khaikin, V.S. Proshina*, G.G. Rodionov**, T.G. Sazhin*, S.V. Sosnovskii*, S.V. Chepur**, S.V. Churashov*, S.S. Ivanchev, A.A. Koltsov**
(*The Kirov Military Medical Academy, St. Petersburg, Russia; **State Scientific Research Testing Institute of Military Medicine, St. Petersburg, Russia)

Eds. V.F. Danilichev, S.A. Novikov,
St. Petersburg,advertising agency“Veko”, 2008, 271 pp.

The monograph reflects the state-of-the-art in the ophthalmocontactology. Particular attention is paid to the possibility of application of remedial contact lenses. Under consideration is the creation of new materials, saturation of the lenses with antibiotics, their application depending on the presence of certain microflora, application of remedial soft contact lenses for perioperational prophylaxis of intraocular infection and for delivering medical care at injuries of the organ of vision, as well as for eye protection under extreme conditions including high smoke content and exposure to unfavorable chemical factors.

A NEW APPROACH TO REGENERATING HEAT AND MOISTURE IN VENTILATION SYSTEMS

Yu.I. Aristov, I.V. Mezentsev*, V.A. Mukhin**

(*Institute of Thermophysics, Novosibirsk, Russia; **Siberian State University of Transport, Novosibirsk, Russia)

Energy Buildings, 40(3) (2008) pp. 204-208.

For countries with a cold climate the large difference (30-60°C) in winter between indoor and outdoor temperatures leads to (a) large heat losses in ventilation systems; (b) moisture freezing at the systems exit; (c) great reduction in the indoor humidity. Here is presented a new approach for regenerating heat and moisture in ventilation systems in cold climates which allows resolution of these problems. The method has been tested under climatic conditions of West Siberia (winter 2005-2006). The prototype system requires very little maintenance, has a low capital cost, is compact and energy efficient. Technical, economic and social aspects of this method are discussed.

FOCUSING AEROGEL RICH OPTIMIZATION

A.Yu. Barnyakov*, M.Yu. Barnyakov*, V.S. Bobrovnikov*, A.R .Buzykaev*, A.F. Danilyuk, V.V. Gulevich*, V.L. Kirillov, S.A. Kononov*, E.A. Kravchenko*, A.P. Onuchin*, S.I. Serednyakov*, V.V. Porosev*
(*Budker Institunte of Nuclear Physics, Novosibirsk, Russia)

Nucl. Instrum. Meth. Phys. Res., Sect. A, 595(1) (2008) pp. 100-103.

The method of improvement of Cherenkov angle resolution in RICH detectors using ‘focusing’ aerogel radiators (FARICH) is under investigation. The ‘focusing’ three-layer aerogel radiator was investigated using a digital radiographic device. The Monte Carlo calculations of velocity resolution based on measured variations of the refractive index in aerogel tile are presented. With the observed variations, π-and K-mesons can be separated up to 8.4 GeV/c, π- and μ-mesons can be separated up to 1.6 GeV/c. The use of sodium fluoride radiator in a RICH detector was studied. NaF radiator extends the working momentum region for the π/K identification down to 0.6 GeV/c. It has been shown that a RICH detector with NaF radiator can achieve a competitive velocity resolution up to 5 GeV/c as compared to single-layer aerogel RICH.

RESULTS FROM R&D OF CHERENKOV DETECTORS AT NOVOSIBIRSK

A.Yu. Barnyakov*, M.Yu. Barnyakov*, K.I. Beloborodov*, V.S. Bobrovnikov*, A.R. Buzykaev*, A.F. Danilyuk, V.B. Golubev*, V.V. Gulevich*, V.L. Kirillov, S.A. Kononov*, E.A. Kravchenko*, A.P. Onuchin*, S.I. Serednyakov*
(*Budker Institunte of Nuclear Physics, Novosibirsk, Russia)

Nucl. Instrum. Meth. Phys. Res., Sect. A, 581(1-2) (2007) pp. 410-414.

The group produces silica aerogels with refractive indices of 1.006–1.13 with good optical transparency. The particle identification systems for the KEDR and the SND detectors based on threshold aerogel counters are described. Cosmic test results for the SND counters are presented. The possibility of employing a RICH with a sodium fluoride crystal radiator for π/K separation up to 5 GeV/c momentum is explored. The combined NaF-aerogel radiator is proposed to decrease the minimum working momentum of the RICH below the Cherenkov threshold in aerogel.

MEMBRANES AND NANOTECHNOLOGIES

V.V. Volkov*, B.V. Mchedlishvili**, V.I. Roldugin***, S.S. Ivanchev,A.B. Yaroslavtsev****
(*Topchiev Institute ofPetrochemical Synthesis, Moscow, Russia;**Shubnikov Institute of Crystallography, Moscow, Russia; ***Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow, Russia; ****Kurnakov Institute of General and Inorganic Chemistry, Moscow, Russia)

Nanotech. Russ., 3(11-12) (2008) pp. 656-687.

The today's state of membrane science, as well as membrane applications and trends in the studies related to nanotechnology are discussed. The detailed analysis is carried out of the use of highly permeable polymer glasses, metallic and ceramic membranes for gas separation, alcohols, ultra pure substances and hydrogen production, as well as aqueous and organic media nanofiltration. The technology and mechanism of the nuclear pore membrane formation are outlined. The approaches are mentioned to form the channels with complex geometry. The ion exchange membranes and polymeric proton-conducting electrolytes are specially discussed. The feature of polyelectrolytes for membranes, membrane structure and transport properties are considered. The membrane modification with organic and inorganic components are described. The achievements in ion exchange membrane use for the pure and deionized water production are discussed. The problems related the fuel cell membrane are outlined. The significant attention is paid to asymmetry transport in nanosize membranes. The mechanisms responsible for the asymmetry in gas and electrolyte transport are discussed.

FLUORINATED PROTON-CONDUCTING NAFION-TYPE MEMBRANES, THE PAST AND THE FUTURE

S.S. Ivanchev

Russ. J. Appl. Chem., 81(4) (2008) pp. 569-584.

By now, considerable advances have been made in the field of fuel cells (FC) operating with polymeric electrolytes in the form of thin membranes. The development in this area is governed by the wide variety of application fields of membrane FC. As for solid-oxide FC, their use is presumably limited to development of high-power installations in which the loss of heat into the environment can be minimized. The authors analyze in what follows the problems solely associated with polymeric electrolytes for membrane FC. A strong stimulus to activation of research in the field of membrane FC was given by the agreement on hydrogen energetics, concluded by the Russian Academy of Sciences and Noril’skii Nikel’ combine. In accordance with this agreement, the research program envisaged a wide variety of studies in hydrogen energetics and fuel cells, including development of polymeric proton-conducting membranes for FC, improvement of catalytic systems on FC electrodes, improvement of the FC design, and fabrication of FC batteries. Taking into account the wide diversity of the problems associated with these tasks, the authors consider in more detail the development of polymeric membrane FC and analyze the synthesis and fabrication of proton-conducting polymeric (primarily fluoropolymeric) membranes for FC.

ASTROCATALYSIS HYPOTHESIS FOR ORIGIN OF LIFE PROBLEM

V.N. Snytnikov

In “Biosphere Origin and Evolution”,
Eds. N. Dobretsov et al., Springer US, 2008, Part 2, pp. 45-53.

Analysis of the available natural science data has allowed the astrocatalysis hypothesis to be formulated. The hypothesis indicates the pre-planetary circumstellar disk as the most probable time and place of the primary abiogenic synthesis of prebiotic organic substances from simple molecules along with the “RNA world” and the life origin. The sequence of self-organization stages that gave rise to the Earth biosphere is determined. Results of computational experiments with supercomputers are used to determine conditions of abiogenic organic compounds in the Earth’s biosphere. In handling the problem of the origins of the Earth’s biosphere, it is necessary to establish and study the role of abiogenic synthesis of prebiotic compounds in the sequence of key stages of the self-organization of matter. The sequence is the evolution of the surroundings from the point of Big Bang towards organic life and further to humans.