Kinetic Model for Formation of Aromatics in the High Temperature Chlorination of Methane1

ABSTRACT A detailed thermochemical kinetic model consisting of 165 reversible reactions has been developed to describe catalyzed polymerization of methane under adiabatic conditions. The model, an extension of that previously proposed (Weissman and Benson, 1984, 1989), was tested against available experimental data for CH3C1 pyrolysis in the absence and presence of CH4 in the temperature range 1260-1310 K (Weissman and Benson, 1984). Predictions of major product yields are reasonable although predictive inadequacies are discussed. Product distributions in the CH4/CI2 reaction were studied as a function of inlet/mixing temperature (To = 750-900 K), reactor pressure (PR = 1.0 —5.0 atmospheres) and CH4:C1, mole ratio (1.0-2.0). Product distribution is shown to be a strong function of inlet temperature and reactanl mole ratio. Choice of these parameters define the “window” of accessible reaction conditions experimentally available for useful product formation. Commercially attractive C2 yields (C2 H 2, C2H4),...

[1]  A. Dean,et al.  Hydrocarbon Radical Reactions with O2: Comparison of Allyl, Formyl, and Vinyl to Ethyl , 1993 .

[2]  A. Dean,et al.  Hydrocarbon radical reactions with oxygen: comparison of allyl, formyl, and vinyl to ethyl , 1993 .

[3]  M. Pilling,et al.  Direct observation of equilibration in the system hydrogen atom + ethylene .dblharw. ethyl radical. Standard enthalpy of formation of the ethyl radical , 1993 .

[4]  D. Gutman,et al.  Weak collision effects in the reaction C2H5 ⇌ C2H4 + H , 1993 .

[5]  Yonghua Chen,et al.  Ab initio study of the structures, rotation/inversion barriers, fundamental frequencies, and thermodynamic functions of .beta.-chloroethyl, .alpha.-chloroethyl, and .alpha.,.alpha.-dichloroethyl radicals , 1992 .

[6]  J. Bozzelli,et al.  Kinetic Study on Pyrolysis and Oxidation of CH3Cl in Ar/H2/O2 Mixtures , 1992 .

[7]  J. Bozzelli,et al.  Chloroform Pyrolysis: Experiment and Detailed Reaction Model , 1992 .

[8]  R. Barat,et al.  Thermal reactions of CH2Cl2 in H2/O2 mixtures: Implications for chlorine inhibition of CO conversion to CO2 , 1992 .

[9]  S. Benson.  Radical processes in the pyrolysis of acetylene , 1992 .

[10]  B. Dellinger,et al.  Oxidative pyrolysis of CH2Cl2, CHCl3, and CCl4-I: Incineration implications , 1991 .

[11]  D. Gutman,et al.  Kinetics of the reactions of partially halogenated methyl radicals (CH2Cl, CH2Br, CH2I, and CHCl2) with molecular chlorine , 1991 .

[12]  S. Benson,et al.  Temperature Coefficients of the Rates of Cl Atom Reactions with C2H6, C2H5, and C2H4. The Rates of Disproportionation and Recombination of Ethyl Radicals , 1991 .

[13]  S. Benson,et al.  Temperature coefficients of the rates of chlorine atom reactions with C2H6, C2H5, and C2H4. The rates of disproportionation and recombination of ethyl radicals , 1991 .

[14]  S. Benson,et al.  Thermochemistry of Acetylenes and Polyacetylenes , 1991 .

[15]  M. Frenklach.  PRODUCTION OF POLYCYCLIC AROMATIC HYDROCARBONS IN CHLORINE CONTAINING ENVIRONMENTS , 1990 .

[16]  W. C. Lineberger,et al.  Bond Strengths of Ethylene and Acetylene , 1990 .

[17]  A. Dean,et al.  Kinetic study on thermal decomposition of chlorobenzene diluted in hydrogen , 1990 .

[18]  P. R. Westmoreland,et al.  Forming benzene in flames by chemically activated isomerization , 1989 .

[19]  D. Gutman,et al.  Kinetics and thermochemistry of ethenyl and chloroethenyl radicals: study of the ethenyl + hydrogen chloride = ethene + chlorine atom and chloroethenyl + hydrogen chloride = chloroethene + chlorine atom reactions , 1989 .

[20]  S. Benson,et al.  Kinetics and thermochemistry of the reaction C2D6 + Cl .dblharw. C2D5 + DCl. The heat of formation of the ethyl-d5 and ethyl radicals , 1989 .

[21]  A. Maccoll,et al.  Heats of formation of alkyl radicals from appearance energies , 1988 .

[22]  J. Holmes,et al.  Heats of formation and bond dissociation energies in halogen-substituted methyl and ethyl radicals , 1988 .

[23]  D. Gutman,et al.  Kinetics and Thermochemistry of CH3, C2H5, and i‐C3H7. Study of the Equilibrium R + HBr ⇌ R‐H + Br , 1988 .

[24]  S. Benson,et al.  Kinetics of the Reaction Cl + C2H4 ⇌ C2H3 + HCl. Heat of Formation of the Vinyl Radical. , 1988 .

[25]  H. Freund,et al.  Detailed chemical kinetic modeling of butylbenzene pyrolysis , 1988 .

[26]  S. Benson,et al.  Rate parameters for the reactions of C/sub 2/H/sub 3/ and C/sub 4/H/sub 5/ with H/sub 2/ and C/sub 2/H/sub 2/ , 1988 .

[27]  S. Benson,et al.  Kinetics of the reaction chlorine atom + ethylene .dblharw. vinyl + hydrogen chloride: heat of formation of the vinyl radical , 1988 .

[28]  D. Gutman,et al.  Kinetics and thermochemistry of methyl, ethyl, and isopropyl. Study of the equilibrium R + HBr .dblharw. R-H + Br , 1988 .

[29]  Wing Tsang,et al.  Critical Review of rate constants for reactions of hydrated electronsChemical Kinetic Data Base for Combustion Chemistry. Part 3: Propane , 1988 .

[30]  R. Blint,et al.  Formation of small aromatic molecules in a sooting ethylene flame , 1988 .

[31]  S. B. Karra,et al.  Analysis of the chemically activated CH2Cl/CH2Cl and CH3/CH2Cl recombination reactions at elevated temperatures using the bimolecular Quantam Rice-Ramsperger-Kassel (QRRK) method , 1988 .

[32]  S. Paddison,et al.  Kinetics of photochlorination of halogen (F, Cl, Br) substituted methanes , 1988 .

[33]  S. Lias,et al.  Structures and heats of formation of C4H+7 ions in the gas phase , 1987 .

[34]  S. Benson,et al.  Analysis of flow dynamics in a new, very low pressure reactor. Application to the reaction: Cl + CH4⇌ HCl + CH3 , 1987 .

[35]  A. D. McLean,et al.  Theoretical investigations of the anaerobic reduction of halogenated alkanes by cytochrome P 450. 1. Structures, inversion barriers, and heats of formation of halomethyl radicals , 1987 .

[36]  M. Pilling,et al.  Observation of Equilibration in the System H + C2H4 ↔ C2H5. The Determination of the Heat of Formation of C2H5 , 1986 .

[37]  R. Timonen,et al.  Kinetics of the reactions of methyl, ethyl, isopropyl, and tert-butyl radicals with molecular chlorine , 1986 .

[38]  R. A. Matula,et al.  Shock-tube pyrolysis of chlorinated hydrocarbons: Formation of soot , 1986 .

[39]  V. S. Jorish,et al.  Thermodynamic properties of twenty-one monocyclic hydrocarbons , 1986 .

[40]  W. Tsang.  Thermodynamic and kinetic properties of the cyclohexadienyl radical , 1986 .

[41]  Stephen E. Stein,et al.  High-temperature stabilities of hydrocarbons , 1985 .

[42]  M. H. Back,et al.  The heat of formation of the ethyl radical , 1984 .

[43]  J. Traeger.  A study of the allyl cation thermochemistry by photoionization mass spectrometry , 1984 .

[44]  A. Ravishankara,et al.  Reaction of hydrogen atom with benzene. Kinetics and mechanism , 1984 .

[45]  S. Benson,et al.  Pyrolysis of methyl chloride, a pathway in the chlorine-catalyzed polymerization of methane , 1984 .

[46]  E. Tschuikow-Roux,et al.  Photochlorination of ethyl chloride and ethyl-d5 chloride , 1984 .

[47]  V. P. Kolesov,et al.  Thermochemistry of Haloethanes , 1983 .

[48]  D. Golden,et al.  Hydrocarbon Bond Dissociation Energies , 1983 .

[49]  S. Benson,et al.  Mechanism of the pyrolysis of C2HCl5, molecular and radical steps , 1982 .

[50]  A. Castelhano,et al.  Heats of formation of some simple alkyl radicals , 1982 .

[51]  M. Dupuis,et al.  Assignment of the infrared spectrum for the ethyl radical , 1982 .

[52]  S. Benson,et al.  The temperature coefficient of the rates in the system Cl + CH4 ⇆ CH3 + HCl, thermochemistry of the methyl radical , 1981 .

[53]  A. Castelhano,et al.  Heats of formation of tert-butyl and ethyl radicals , 1981 .

[54]  S. Stein,et al.  Very‐low‐pressure pyrolysis of ethylbenzene, isopropylbenzene, and tert‐butylbenzene , 1981 .

[55]  S. Benson.  foundations of chemical kinetics , 1960 .

[56]  Ko Saito,et al.  The Thermal Unimolecular Decomposition of Methyl Chloride behind Shock Waves , 1980 .

[57]  R. Watson,et al.  Temperature-dependent rate constants for the reaction of ground-state chlorine with simple alkanes , 1980 .

[58]  D. Golden,et al.  Thermochemistry of some six-membered cyclic and polycyclic compounds related to coal , 1977 .

[59]  K. Homann,et al.  J. A. Kerr and M. J. Parsonage: Evaluated Kinetic Data on Gas Phase Addition Reactions. Reactions of Atoms and Radicals with Alkenes, Alkynes and Aromatic Compounds. Butterworths, London 1972, 384 S., Preis: £12.00 , 1973, Berichte der Bunsengesellschaft für physikalische Chemie.

[60]  S. Benson,et al.  Entropies and heat capacities of cyclic and polycyclic compounds , 1970 .

[61]  D. Golden,et al.  Additivity rules for the estimation of thermochemical properties , 1969 .

[62]  D. Golden,et al.  Equilibrium constant for allyl radical recombination. Direct measurement of "allyl resonance energy" , 1969 .

[63]  S. Benson,et al.  Entropies and heat capacities of free radicals , 1969 .

[64]  D. Golden,et al.  Free-radical and molecule thermochemistry from studies of gas-phase iodine-atom reactions , 1969 .

[65]  S. Benson,et al.  A Method for Estimating the Arrhenius A Factors for Four- and Six-Center Unimolecular Reactions , 1967 .

[66]  D. Golden,et al.  The Kinetics and Mechanism of the Reaction I2 + C3H6 →← C3H5I + HI and the Heat of Formation of the Allyl Radical1 , 1966 .

[67]  G. Huybrechts,et al.  Atomic Chlorination of Simple Hydrocarbon Derivatives in the Gas Phase. , 1963 .

[68]  R. J. Kee,et al.  Chemkin-II : A Fortran Chemical Kinetics Package for the Analysis of Gas Phase Chemical Kinetics , 1991 .

[69]  W. Forst,et al.  Ultraviolet absorption spectra of the CH2Cl and CHCl2 radicals and the kinetics of their self-recombination reactions from 273 to 686 K , 1991 .

[70]  M. H. Back,et al.  Rate constants for abstraction of hydrogen from ethylene by methyl and ethyl radicals over the temperature range 650–770 K , 1990 .

[71]  E. Tschuikow-Roux,et al.  Kinetics of .alpha.- and .beta.-hydrogen abstraction from ethyl chloride by bromine atoms: estimate of carbon-hydrogen bond dissociation energies and heat of formation of CH3CHCl and CH2CH2Cl radicals , 1990 .

[72]  S. Benson,et al.  Mechanism of soot initiation in methane systems , 1989 .

[73]  D. A. Sullivan,et al.  Gas-Phase Ion and Neutral Thermochemistry , 1988 .

[74]  R. Minet,et al.  Commodity chemicals from natural gas by methane chlorination , 1987 .

[75]  Stephen J. Paddison,et al.  Bond dissociation energies and radical heats of formation in CH3Cl, CH2Cl2, CH3Br, CH2Br2, CH2FCl, and CHFCl2 , 1987 .

[76]  M. Pilling,et al.  Observation of equilibration in the system atomic hydrogen + ethylene .dblharw. ethyl. The determination of the heat of formation of ethyl radical , 1986 .

[77]  Kenneth R. Hall,et al.  Thermodynamic Properties of Key Organic Oxygen Compounds in the Carbon Range C1 to C4. Part 1. Properties of Condensed Phases , 1985 .

[78]  S. Benson,et al.  Heat of formation of the CHCl2 radical. Bond dissociation energies in chloromethanes and chloroethanes , 1983 .

[79]  G. B. Skinner,et al.  Ideal Gas Thermodynamic Properties of CH3, CD3, CD4, C2D2, C2D4, C2D6, C2H6, CH3N2CH3, and CD3N2CD3 , 1982 .

[80]  J. Kerr,et al.  CRC handbook of bimolecular and termolecular gas reactions , 1981 .

[81]  J. Traeger,et al.  Free radicals by mass spectrometry XLVI. Heats of formation of C5H7and C5H9 radicals and cations , 1976 .

[82]  Bruno J. Zwolinski,et al.  Ideal Gas Thermodynamic Properties of Eight Chloro- and Fluoromethanes , 1974 .

[83]  A. S. Rodgers,et al.  Ideal Gas Thermodynamic Properties of Six Chloroethanes , 1974 .

[84]  M. Parsonage,et al.  Evaluated kinetic data on gas phase addition reactions: Reactions of atoms and radicals with alkenes, alkynes and aromatic compounds, , 1972 .

[85]  D. Bafus,et al.  Enthalpies of formation of the monohalomethyl radicals from mass spectrometric studies of the dihalomethanes , 1971 .

[86]  A. Trotman‐Dickenson,et al.  Pyrolysis of 4-chlorobut-1-ene , 1970 .

[87]  J. D. Cox,et al.  Thermochemistry of organic and organometallic compounds , 1970 .

[88]  G. Huybrechts,et al.  Bond energies in chloroethanes and chloroethyl radicals , 1969 .

[89]  D. R. Stull,et al.  The chemical thermodynamics of organic compounds , 1969 .

[90]  A. Maccoll,et al.  Gas-phase eliminations. Part VII. The pyrolysis of substituted 1-phenylethyl chlorides , 1968 .

[91]  P. J. Thomas.  Kinetics of the thermal decomposition of 3-chlorobut-1-ene and 3-chloro-2-methylbut-1-ene , 1967 .

[92]  A. Trotman‐Dickenson,et al.  The reactions of alkyl radicals. Part XIII. The additions of methyl, isopropyl, and t-butyl radicals to propyne and the isomerisation of alkenyl radicals , 1967 .

[93]  D. R. Stull.  JANAF thermochemical tables , 1966 .

[94]  H. Steiner,et al.  588. The kinetics and mechanism of the thermal cyclisation of hexa-1,cis-3,5-triene to cyclohexa-1,3-diene , 1964 .

[95]  C. P. Quinn,et al.  768. The entropies of alkyl radicals , 1964 .