Vibrational energy storage in high pressure mixtures of diatomic molecules

CO/N₂, CO/Ar/O₂, and CO/N₂/O₂ gas mixtures are optically pumped using a continuous wave CO laser. Carbon monoxide molecules absorb the laser radiation and transfer energy to nitrogen and oxygen by vibration–vibration energy exchange. Infrared emission and spontaneous Raman spectroscopy are used for diagnostics of optically pumped gases. The experiments demonstrate that strong vibrational disequilibrium can be sustained in diatomic gas mixtures at pressures up to 1 atm, with only a few Watts laser power available. At these conditions, measured first level vibrational temperatures of diatomic species are in the range T_V=1900–2300 K for N₂, T_V=2600–3800 K for CO, and T_V=2200–2800 K for O₂. The translational–rotational temperature of the gases does not exceed T=700 K. Line-of-sight averaged CO vibrational level populations up to v=40 are inferred from infrared emission spectra. Vibrational level populations of CO (v=0–8), N₂ (v=0–4), and O₂ (v=0–8) near the axis of the focused CO laser beam are inferred from the Raman spectra of these species. The results demonstrate a possibility of sustaining stable nonequilibrium plasmas in atmospheric pressure air seeded with a few percent of carbon monoxide. The obtained experimental data are compared with modeling calculations that incorporate both major processes of molecular energy transfer and diffusion of vibrationally excited species across the spatially nonuniform excitation region, showing reasonably good agreement.     

Unusual Disordering of Potassium Ions in the Structures of Cluster Rhenium Thiohalides K3[Re6S7Br7] and K4[Re6S8Cl6]

New cluster compounds — rhenium and potassium thiohalides K₃Re₆S₇Br₇ (I) and K₄Re₆S₈Cl₆ (II) — have been synthesized. Their crystal structures have been determined by single crystal X-ray diffraction. The compounds are monoclinic; (I): space group P2₁/c, a = 9.32(1) Å, b = 13.528 Å, c = 12.413 Å, β = 110.21°, Z = 2, R = 0.038; (II): space group C2/m, a = 10.614 Å, b = 17.268 Å, c = 10.448 Å, β = 110.755°, Z = 2, R = 0.042. In both structures, the potassium ions are considerably distorted. The occupancies of the potassium sites are 0.17-0.34 (I) and 0. 01-0.26 (II), correlating well with the coordination numbers (c.n. 7-10 and 2-7 for I and II, respectively). In I, adjacent positions of potassium atoms are aggregated into discrete tetrahedral and angular clusters; in II, the individual (four-and six-membered) cyclic clusters of potassium sites are present along with bent chains of vertex-and edge-sharing tetrahedral “potassium clusters.” The shortest K-K distances in these “clusters” vary from 1.31 Å to 1.54 Å (I) and from 0.66 Å to 1.65 Å (II). The “instability” of the potassium site suggests that I and II are ion conductors.Original Russian Text Copyright © 2004 by S. F. Solodovnikov, S. S. Yarovoi, Yu. V. Mironov, A. V. Virovets, and V. E. Fedorov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 909–917, September–October, 2004.     

Thermodynamics of binary mixtures containing alkynes. II

Molar excess enthalpiesH ^E of 1-hexyne + carbon tetrachloride, + dipropyl ether, + triethylamine, and of 3-hexyne + carbon tetrachloride, + dipropyl ether, + triethylamine at 298.15 K and atmospheric pressure were measured with aPicker-type flow microcalorimeter over the whole concentration range. At equimolar concentration,H ^E of 3-hexyne + carbon tetrachloride is stronglyexothermic (–499 J mol^–1), in contrast toH ^E =+14 J mol^–1 for the 1-hexyne system. As expected, for the ether and amine systems inverse behavior is observed: because of the active hydrogen of terminal alkynes the enthalpy of mixing at equimolar concentration is more exothermic with 1-hexyne (–185 J mol^–1, dipropyl ether; –300 J mol^–1, triethylamine) than with 3-hexyne (–25 J mol^–1, dipropyl ether; –92 J mol^–1, triethylamine). The curveH ^E vs. mole fraction is considerably skewed for 3-hexyne (x ₁) + triethylamine, the minimum being ca. –197 J mol^–1 atx ₁0.9.

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Thermodynamik binärer Mischungen mit Alkinen als eine Komponente. II. Zusatzenthalpien binärer Mischungen von 1-Hexin und 3-Hexin mit Tetrachlorkohlenstoff, Dipropyläther und Triäthylamin bei 298,15 K

Zusammenfassung Die molaren ZusatzenthalpienH ^E der sechs binären Systeme 1-Hexin + CCl₄, + Dipropyläther, + Triäthylamin, und 3-Hexin + CCl₄, + Dipropyläther, + Triäthylamin wurden bei 298,15 K und Atmosphärendruck über den gesamten Konzentrationsbereich mit einem dynamischen Strömungsmikrokalorimeter nachPicker gemessen.H ^E des Systems 3-Hexin + CCl₄ ist starkexotherm (–499 J mol^–1 fürx=0,5),H ^E des Systems 1-Hexin + CCl₄ endotherm (+14 J mol^–1,x=0,5). Hingegen verhalten sich die Mischungen Hexin + Dipropyläther bzw. + Triäthylamin den Erwartungen entsprechend. Wegen des aktiven Wasserstoffs endständiger Alkine ist die Zusatzenthalpie mit 1-Hexin stärker exotherm (–185 J mol^–1 mit Dipropyläther und –300 J mol^–1 mit Triäthylamin,x=0,5) als mit 3-Hexin (–25 J mol^–1 bzw. –92 J mol^–1). Die molare Zusatzenthalpie des Systems 3-Hexin (x ₁) + Triäthylamin ist ausgeprägt asymmetrisch mit einem Minimum von etwa –197 J mol^–1 beix ₁0,9.

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Communicated in part at the 2. Ulmer Kalorimetrietage, March 24–25, 1977, Ulm, Federal Republic of Germany.     

Effect of introduction of heterocyclic moieties into polymer backbone on gas transport properties of fluorinated poly(ether imide) membranes

The effects of incorporation of heterocyclic moieties into fluorinated poly(ether imide) membranes on their gas transport properties were investigated. Four novel fluorinated poly(ether imide) (PEI) membranes were prepared from four different bis(ether amine)s namely, 4,4-bis[3′-trifluromethyl-4′(4′′-aminobenzoxy)bezyl]biphenyl (BAQP); 1,4-bis[3′-trifluromethyl-4′(4′′-aminobenzoxy)bezyl] benzene (BATP); 2,6-bis[3′-trifluromethyl-4′(4′′-aminobenzoxy)bezyl]pyridine (BAPy) and 2,5-bis[3′-trifluromethyl-4′(4′′-aminobenzoxy)bezyl]thiophene (BATh), and a fluorinated dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane (6FDA) as a common dianhydride. Gas transport properties of these membranes were measured to investigate the effect of chemical structure on gas permeation and diffusion processes over four different gases (e.g., CH₄, N₂, O₂ and CO₂) at different temperatures (e.g., 35, 45 and 55 °C) at an applied pressure of 3.5 bar. It has been found that at 35 °C the permselectivities of BAPy and BATh based polymeric membranes (6.4 and 6.6, respectively) toward O₂ relative to N₂ are higher in comparison to BAQP and BATP (5.5 and 5.3, respectively) containing PEI membranes. The permeability coefficient of CO₂ for BAPy and BATh (51.92 and 45.31, respectively at 35 °C) based PEI membranes were observed to be much higher than BAQP and BATP based membranes (36.61 and 33.51, respectively at 35 °C) with comparable selectivity values of CO₂ relative to CH₄. All these membranes exhibit higher CO₂/CH₄ selectivity than those of common glassy polymers e.g., cellulose acetate, polysulfone and polycarbonate. The order of permeability of these gases was found as CO₂ > O₂ > N₂ > CH₄. The temperature dependency of permeation and diffusion processes enables to calculate the activation energies of the permeation and diffusion processes for these four different gases through four PEI membranes.     

Präparative Darstellung von Disilanyl- und Trisilanyljodiden

Zusammenfassung Die Darstellung von Si₂H₅J sowie von Si₂H₄J₂ (SiH₃–SiHJ₂+SiH₂J–SiH₂J), Si₃H₇J (SiH₃–SiH₂–SiH₂J+SiH₃–SiHJ–SiH₃) und Si₃H₆J₂ (Isomerengemisch) durch Umsetzung der entsprechenden Silane mit elementarem Jod (ohne Verwendung eines Lösungsmittels) wird mitgeteilt. Durch katalytische Mengen Alkohol wird die Reaktion von Jod mit Silanen beschleunigt, gleichzeitig jedoch die Spaltung der Si–Si-Bindung gefördert.

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Preparation of disilanyl iodide and trisilanyl iodide

The preparation of Si₂H₅J as well as Si₂H₄J₂ (SiH₃–SiHJ₂+SiH₂J–SiH₂J), Si₃H₇J (SiH₃–SiH₂–SiH₂J+SiH₃–SiHJ–SiH₃) and Si₃H₆J₂ (isomeric mixture) by reaction of the corresponding silanes with elementary iodine without using a solvent is communicated. The reaction of iodine with silanes is accelerated by catalysings amounts of alcohol. At the same time, however, the cleavage of the Si–Si-bond is stimulated.

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Mit 3 Abbildungen

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19. Mitt.:F. Fehér, D. Schinkitz undH. Strack, Z. anorg. allgem. Chem.385, 202 (1971).

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B. Mostert, Dissertation Univ. Köln 1961.

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A. G. Wronka, Dissertation Univ. Köln 1961.

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G. Betzen, Dissertation Univ. Köln 1967,G. Betzen, Diplomarbeit Univ. Köln 1963.     

Relative efficiencies of substituted aromatic monocarboxylic acids as eluents in ion chromatographic separation of inorganic and organic anions

The eluent strengths of para, ortho and meta substituted hydroxy-, nitro-, amino- and sulfobenzoic acids in single column ion chromatographic separations of inorganic and organic anions have been evaluated and compared with benzoic acid.o-Sulfobenzoic acid turns out to be a stronger and efficient eluent compared to others for the separation and determination of monovalent (Cl^–, NO ₂ ^– , Br^–, NO ₃ ^– ) and divalent (SO ₄ ^2– , SeO ₄ ^2– , S₂O ₃ ^2– , S₂O ₆ ^2– ) inorganic anions. In addition it also functions as an appropriate mobile phase for the detection and quantification of some substituted benzoate ions in an aqueous medium.     

Image Intensification in Silver Halide Photographic Materials for Detection of High-Energy Radiation by Reprecipitation of Elemental Silver

A process for the intensification of silver images on AgHal photographic materials designed for detection of high-energy (X- and γ-ray) radiation was proposed, which is based on the “reprecipitation” of elemental silver and a decrease in its dispersion and comprises the treatment of silver with an aqueous solution containing potassium hexacyanoferrate(III) and potassium chloride or bromide at the first step and with a solution containing tin(II) chloride, potassium thiocyanate, sodium N,N′-ethylenediamine tetraacetate, and potassium hydroxide at the second step. By this process, the optical densities of image over a wide (0.5–2.0) range was increased by a factor of 3–5; as a result, the photographic sensitivity S _0.85 and S _2.00 was enhanced by almost an order of magnitude with the retained or slightly increased gradient g, fog density D ₀, and resolving power of the material.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 5, 2005, pp. 373–378.Original Russian Text Copyright © 2005 by Mikhailov, Kondakov, Krikunenko.     

Permeability and thermal properties of PDMS/LDPE multilayer composite membranes

This work reports on the preparation and properties of polydimethylsiloxane (PDMS)/low‐density polyethylene (LDPE) multilayer composite polymer membranes (MCPM) for gas separation applications. The membranes were produced by combining sequential coating with melt‐extrusion/salt leaching techniques. In particular, the gas sorption and permeation properties at different pressure (40–90 psig) and temperature (27–55 °C) are reported with morphology and thermogravimetric properties. The results show that a 20 μm PDMS layer was able to penetrate the microporous LDPE surface layer substrate leading to improved interfacial adhesion. Based on the different gases (CO₂, CH₄, and C₃H₈) solubility, permeability, and diffusivity obtained, these membranes are seen as good candidates for industrial gas separations. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1045–1052     

Determination of Trace Impurities of H2, O2, Ar, N2, CO, CO2, and Hydrocarbons in High-Purity Monosilane by Gas Chromatography

Procedures were proposed for the determination of impurities of permanent gases (H₂, O₂, Ar, N₂, and CO), carbon dioxide, and hydrocarbons in high-purity monosilane by gas chromatography with detection limits of 1–3 ppm, 2 ppm, and 0.02–0.04 ppm, respectively, which are lower by 1–2 orders of magnitude than those published in the literature. The procedures make it possible to check the compliance of the purity of monosilane with present standards of microelectronics (TU 48-0513-057.0-91).     

Preparation and characterization of a composite PDMS membrane on CA support

Polydimethylsiloxane (PDMS) is the most commonly used membrane material for the separation of condensable vapors from lighter gases. In this study, a composite PDMS membrane was prepared and its gas permeation properties were investigated at various upstream pressures. A microporous cellulose acetate (CA) support was initially prepared and characterized. Then, PDMS solution, containing crosslinker and catalyst, was cast over the support. Sorption and permeation of C₃H₈, CO₂, CH₄, and H₂ in the prepared composite membrane were measured. Using sorption and permeation data of gases, diffusion coefficients were calculated based on solution‐diffusion mechanism. Similar to other rubbery membranes, the prepared PDMS membrane advantageously exhibited less resistance to permeation of heavier gases, such as C₃H₈, compared to the lighter ones, such as CO₂, CH₄, and H₂. This result was attributed to the very high solubility of larger gas molecules in the hydrocarbon‐based PDMS membrane in spite of their lower diffusion coefficients relative to smaller molecules. Increasing feed pressure increased permeability, solubility, and diffusion coefficients of the heavier gases while decreased those of the lighter ones. At constant temperature (25°C), empirical linear relations were proposed for permeability, solubility, and diffusion coefficients as a function of transmembrane pressure. C₃H₈/gas solubility, diffusivity, and overall selectivities were found to increase with increasing feed pressure. Ideal selectivity values of 9, 30, and 82 for C₃H₈ over CO₂, CH₄, and H₂, respectively, at an upstream pressure of 8 atm, confirmed the outstanding separation performance of the prepared membrane. Copyright © 2009 John Wiley & Sons, Ltd.     

Interaction of iron carbonyls with Lewis bases

The interaction of iron carbonyls Fe _n (CO) _m (wheren = 1,m = 5;n = 2,m = 9;n = 3,m = 12) with anionic Lewis bases (H^–, F^–, Cl^–, Br^– , I^–, CN^–, SCN^–, N₃ ^–, MeSO₃ ^–, MeCO₂ ^–, CF₃CO₂ ^–, S₂ ^–, CO₃ ^2–, and SO₄ ^2–) passes through two-stage redox-disproportionation. The first stage is the formation of an iron carbonyl-base complex, [Fe _n (CO) _m–1C(O)L]^–, and the second is a single-electron reduction of this complex by another molecule of the initial iron carbonyl, giving rise to Fe(l) and Fe(–l) derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 248–249, January, 1996.     

Off-axis field approximations for ion traps with apertures

In recent work (Int. J. Mass Spec., vol. 282, pp. 112–122) we have considered the effect of apertures on the fields inside rf traps at points on the trap axis. We now complement and complete that work by considering off-axis fields in axially symmetric (referred to as “3D”) and in two dimensional (“2D”) ion traps whose electrodes have apertures, i.e., holes in 3D and slits in 2D. Our approximation has two parts. The first, E_noAperture, is the field obtained numerically for the trap under study with apertures artificially closed. We have used the boundary element method (BEM) for obtaining this field. The second part, E_{dueToAperture}, is an analytical expression for the field contribution of the aperture.In E_{dueToAperture}, aperture size is a free parameter. A key element in our approximation is the electrostatic field near an infinite thin plate with an aperture, and with different constant-valued far field intensities on either side. Compact expressions for this field can be found using separation of variables, wherein the choice of coordinate system is crucial. This field is, in turn, used four times within our trap-specific approximation.The off-axis field expressions for the 3D geometries were tested on the quadrupole ion trap (QIT) and the cylindrical ion trap (CIT), and the corresponding expressions for the 2D geometries were tested on the linear ion trap (LIT) and the rectilinear ion trap (RIT). For each geometry, we have considered apertures which are 10%, 30%, and 50% of the trap dimension. We have found that our analytical correction term E_{dueToAperture}, though based on a classical small-aperture approximation, gives good results even for relatively large apertures.     

Effects of strong inter-hydrogen bond dynamical couplings in the polarized IR spectra of adipic acid crystals

This paper presents the results of the re-investigation of polarized IR spectra of adipic acid and of its d₂, d₈ and d₁₀ deuterium derivative crystals. The spectra were measured at 77 K by a transmission method using polarized light for two different crystalline faces. Theoretical analysis concerned linear dichroic effects and H/D isotopic effects observed in the spectra of the hydrogen and deuterium bonds in adipic acid crystals at the frequency ranges of the ν_O–H and the ν_O–D bands. The two-branch fine structure pattern of the ν_O–H and ν_O–D bands and the basic linear dichroic effects characterizing them were ascribed to the vibronic mechanism of vibrational dipole selection rule breaking for IR transitions in centrosymmetric hydrogen bond dimers. It was proved that for isotopically diluted crystalline samples of adipic acid, a non-random distribution of protons and deuterons occurs in the dimers (H/D isotopic “self-organization” effect). This effect results from the dynamical co-operative interactions involving the dimeric hydrogen bonds.     

The character of interaction of organometallic derivatives of 4-nitrophenol and 4-nitrothiophenol with anions in different media

Interaction of R _n M-derivatives of 4-nitrophenol and thiophenol (R _n M= PhHG, PPh₃Au, Ph₃Sn, Ph₄Sb) with a set of inorganic and organic anions (Cl^–, Br^–, I^–, CN^–, [PhOCO]^–, [4-NO₂C₆H₄OCO]^–) was studied by IR and electronic spectroscopy in solvents with different polarities and coordinating properties (C₆H₆, CH₂Cl₂, DMSO). The dependence of the character of the interaction with the anions on the nature of the metal atom and heteroatom, the type of anions and the nature of the media was analyzed. Such interaction leads to ion-molecular complexes, and also to dissociation of the X-M bond (X = O, S, M = Au, Hg. Sb) with formation of the (4-NO₂C₆H₄X)^– anion even in weakly polar media. Only in the case of 4-NO₂C₆H₄OSnPh₃ does the reaction stop at the stage of complex formation. In other cases the role of complex formation with anions is less than with neutral coordinating reagents.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1838–1841, July, 1996.     

Structural and magnetic properties of “one-dimensional” barium vanadium triselenide

BaVSe₃ has been synthesized and its crystal structure determined at 293(2)°K. The structure was solved in the hexagonal space group P6₃/mmc (D⁴_6h), with a = 6.9990(11) and c = 5.8621(13) Å. Scans (2 Θ) of a polycrystalline sample revealed that BaVSe₃ undergoes a transition to an orthorhombic unit cell (b′ 3^1/2 a, a′ a, c′ c) at 303(5)°K. Magnetic susceptibility measurements between 4 and 300°K indicate that BaVSe₃ is paramagnetic down to 41(1)°K, where magnetic ordering occurs, with a magnetic moment in the ordered phase of 0.2 μ_B per vanadium atom. The orthorhombic lattice distortion may be caused by the “freezing in” of “soft” vibrational modes.     

Multiple-scattering approach to Sn L3-edge X-ray absorption near-edge structure (XANES) analyses for organic tin compounds

We apply multiple-scattering calculations to the analyses of Sn L₃-edge X-ray absorption near-edge structure (XANES) spectra for environmental organotin compounds such as SnCl_4−nMe_n, SnCl_4−nBt_n, and SnCl_4−nPh_n (n = 0–4) where Me = CH₃, Bt = C₄H₉, and Ph = C₆H₅. The XANES peak at 3960 eV has rich information on the local structure. Referring to the optimized structures by density functional theory (DFT) calculations, multiple-scattering calculations well explain the observed spectral changes for different “organic extents”. The present study also supports the widely-used semiempirical rule called ‘Natoli’s rule’ for these environmental compounds, which will be useful to use XANES spectra for the practical analytical tools.     

CO2 permeation properties of poly(ethylene oxide)-based segmented block copolymers

This paper discusses the gas permeation properties of poly(ethylene oxide) (PEO)-based segmented block copolymers containing monodisperse amide segments. These monodisperse segments give rise to a well phase-separated morphology, comprising a continuous PEO phase with dispersed crystallised amide segments. The influence of the polyether phase composition and of the temperature on the permeation properties of various gases (i.e., CO₂, N₂, He, CH₄, O₂ and H₂) as well as on the pure gas selectivities were studied in the temperature range of −5 °C to 75 °C. The CO₂ permeability increased strongly with PEO concentration, and this effect could partly be explained by the dispersed hard segment concentration and partly by the changing chain flexibility. By decreasing the PEO melting temperature the low temperature permeabilities were improved. The gas transport values were dependant on both the dispersed hard segment concentration and the polyether segment length (length between crosslinks). The gas selectivities were dependant on the polyether segment length and thus the chain flexibility.     

A thermodynamic interpretation of the behavior of higher fatty alcohols and acids upon the chromatographic paper

An idea was presented of treating the chromatographed substance as a “solute,” and the chromatographic system, composed of the stationary and the mobile phase as a “solvent.” Moreover the concept of “local equilibrium” was introduced, allowing to regard a given chromatographic spot as a “binary solution.” Thus a possibility arose to apply the classical thermodynamic approach, normally used for binary solutions, and namely: μ_i = μ_i + RT ln x_iƒ_i, where μ_i—chemical potential of the “i”-th compound in the solution, μ_i—chemical potential of the pure “i”-th compound, x_i-molar fraction of the “i”-th compound, ƒ_i—its activity coefficient, in a modified form, suitable for the chromatographic purpose.     

Gas-permeation continuous flow coulometric analysis: determination of sulphur dioxide

 A gas permeation system using two gaseous streams flowing on both sides of a membrane is developed. This gas permeation device and a coulometric detector are adapted for the continuous measurement of relatively high concentrations of sulphur dioxide. The interferences of other gases (NO₂, NO and CO₂) can be eliminated by using a scrubber behind the gas permeation device in the acceptor stream. The effects of the donor flow rates and gas pressure as well as the membrane thickness on the signal are discussed. The relative standard deviation is 1.3% (n=7) for 2.002×10^-3 mol/mol certified sulphur dioxide. Received: 19 July 1996/Revised: 22 October 1996/Accepted: 29 October 1996     

Pulverized coal plasma gasification

A number of experiments on the plasma-vapor gasification of brown coals of three types have been carried out using an experimental plant with an electric-arc reactor of the combined type. On the basis of the material and heat balances, process parameters have been obtained: the degree of carbon gasification (_c), the level of sulfur conversion into the gas phase (_s), the synthesis gas concentration (CO+Hz) in the gaseous products, and the specific power consumption for the gasification process. The degree of gasification was 90.5-95.0%, the concentration of the synthesis gas amounted to 84.7–85.7%, and the level of sulfur conversion into the gas phase was 94.3–96.7%. Numerical study of the process of plasma gasification of coals was carried out using a mathematical model of motion, heating, and gasification of polydisperse coal particles in an electric-arc reactor of the combined type with an internal heat source (arc). The initial conditions for a conjugate system of nonlinear differential equations of the gas dynamics and kinetics of a pulverized coal stream interacting with the electric arc and oxidizer (water vapor) agree with the initial conditions of the experiments. The computation results satisfactorily correlate with the experimental data. The mathematical model can be used for the determination of reagent residence time and geometrical dimensions of the plasma reactor for the gasification of coals.Nomenclature c _i volume concentration of components (kmol m^–3) - x longitudinal coordinate (m) - f _i source members, determined by variation of the ith component due to chemical reactions in unit volume in unit time (kmol m^–3s^–1) - velocity (m s^–1) - M _s ash mass in one particle (kg) - C _D particle drag coefficient - 3.14 - r _s particle radius (m) - d particle diameter (m) - density (kg m^–3) - C _p heat capacity of components (J mol^t– K^–1) - Q _j thermal effect of reaction (J kmol^–1) - E_j activation energy of reaction - N _l volume concentration of particles of thelth fraction (m^–3) - T temperature (K) - emissivity factor of coal particles - 5.67 × 10^–8, blackbody emissivity coefficient (W m^–2 K^–4) - P pressure (Pa) - S reactor cross section (m²) - D reactor diameter (m) - V reactor volume (m³) - L _R reactor length (m) - F _W friction force on the wall (N) - f _g friction coefficient - residence time (s) - Nu Nusselt number - Re Reynolds number - Pr Prandtl number - thermal conductivity of gas (J m^– s^–1 K^–1) - R 8.3 × 10³, universal gas constant (J kmol K^–1) - µ _i molecular mass of component (kg kmol^–1) - dynamic viscosity coefficient of gas (kg m^–1 s^–1) - thermal efficiency of plasma reactor - q_arc specific heat flow from arc (W m^–3) - P ₁ heat supplied in vapor at T = 405 K (W) - P ₂ heat loss to wall (W) - P ₃ heat loss in the gas and slag separator chamber (W) - P ₄ heat loss in the synthesis gas oxidation chamber (W) - P ₅ heat loss in the slag catcher (W) - P ₆ heat carried away in the off-gas (W) - P heat input of arc (W) - P _arc electric power of arc (W) - Q_sp specific power consumption (kw Hr kg^–1) - d _w specific heat flow to wall (W m^–2) - _c degree of carbon gasification (%) - _s level of sulfur conversion into gas phase (%)