An experimental and modeling study of ethanol oxidation kinetics in an atmospheric pressure flow reactor

Experimental profiles of stable species concentrations and temperature are reported for the flow reactor oxidation of ethanol at atmospheric pressure, initial temperatures near 1100 K and equivalence ratios of 0.61–1.24. Acetaldehyde, ethene, and methane appear in roughly equal concentrations as major intermediate species under these conditions. A detailed chemical mechanism is validated by comparison with the experimental species profiles. The importance of including all three isomeric forms of the C2H5O radical in such a mechanism is demonstrated. The primary source of ethene in ethanol oxidation is verified to be the decomposition of the C2H4OH radical. The agreement between the model and experiment at 1100 K is optimized when the branching ratio of the reactions of C2H5OH with OH and H is defined by (30% C2H4OH + 50% CH3CHOH + 20% CH3CH2O) + XH. As in methanol oxidation, HO2 chemistry is very important, while the H + O2 chain branching reaction plays only a minor role until late in fuel decay, even at temperatures above 1100 K.

[1]  Richard A. Yetter,et al.  Flow Reactor Studies of Carbon Monoxide/Hydrogen/ Oxygen Kinetics , 1991 .

[2]  T. S. Norton,et al.  Toward a comprehensive mechanism for methanol pyrolysis , 1990 .

[3]  A. Wagner,et al.  Rate constants for the reactions O + C2H2 and O + C2D2 .fwdarw. products, over the temperature range .apprx.850-1950 K, by the flash photolysis-shock tube technique. Determination of the branching ratio and a further theoretical analysis , 1990 .

[4]  T. S. Norton,et al.  Some New Observations on Methanol Oxidation Chemistry , 1989 .

[5]  W. Hess,et al.  Catalytic conversion of alcohols to alkenes by OH , 1988 .

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

[7]  James A. Miller,et al.  Kinetics of the reaction between oxygen atoms and ethyl radicals , 1988 .

[8]  A. Wagner,et al.  The addition and dissociation reaction atomic hydrogen + carbon monoxide .dblharw. oxomethyl. 2. Experimental studies and comparison with theory , 1987 .

[9]  Wing Tsang,et al.  Chemical Kinetic Data Base for Combustion Chemistry. Part 2. Methanol , 1987 .

[10]  E. Kaiser.  A modeling study of the oxidation of propionaldehyde in the negative temperature coefficient regime , 1987 .

[11]  P. R. Westmoreland,et al.  Bimolecular QRRK analysis of methyl radical reactions , 1987 .

[12]  U. Meier,et al.  Reactions in a non-uniform flow tube temperature profile: effect on the rate coefficient for the reaction C2H5OH+OH , 1987 .

[13]  Wing Tsang,et al.  Chemical Kinetic Data Base for Combustion Chemistry. Part I. Methane and Related Compounds , 1986 .

[14]  C. Westbrook,et al.  Acetaldehyde oxidation in the negative temperature coefficient regime: Experimental and modeling results , 1986 .

[15]  H. Grotheer,et al.  Absolute rate constant for the reaction of oxygen(3P) with ethanol , 1986 .

[16]  R. Atkinson.  Estimations of OH radical rate constants from H‐atom abstraction from C ? H and O ? H bonds over the temperature range 250‐1000 K , 1986 .

[17]  K. Bhaskaran,et al.  High-temperature reactions of triplet methylene and ketene with radicals , 1986 .

[18]  P. Greenhill,et al.  The Rate-Constant of the Reaction of Hydroxyl Radicals With Methanol, Ethanol and (D3)Methanol , 1986 .

[19]  G. Rotzoll.  High-temperature pyrolysis of ethanol , 1985 .

[20]  J. Whitehead,et al.  Dynamics of hydrogen atom abstraction in the reaction atomic oxygen(3P) + ethanol , 1985 .

[21]  D. Gutman,et al.  Kinetics of polyatomic free radicals produced by laser photolysis. 3. Reaction of vinyl radicals with molecular oxygen , 1984 .

[22]  U. Meier,et al.  Temperature dependence and branching ratio of the C2H5OH+OH reaction , 1984 .

[23]  J. Warnatz,et al.  Calculation of Burning Velocity and Flame Structure in Methanol – Air Mixtures , 1983 .

[24]  F. P. Tully.  Laser photolysis/laser-induced fluorescence study of the reaction of hydroxyl radical with ethylene , 1983 .

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

[26]  Henri James,et al.  Etude de l'oxydation et de l'auto-inflammation du méthanol dans le domaine de températures 500-600°C , 1982 .

[27]  W. Tsang.  Comparison between experimental and calculated results on the decomposition of chemically activated alcohols , 1976 .

[28]  I. Glassman,et al.  High-temperature pyrolysis of acetaldehyde , 1975 .

[29]  M. G. Dodson,et al.  A shock-tube study of the ignition of methanol and ethanol with oxygen , 1971 .

[30]  D. F. Lieb,et al.  A radioisotopic tracer study of carbon formation in ethanol-air diffusion flames , 1970 .

[31]  C. Tipper,et al.  The cool flame combustion of ethanol , 1969, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[32]  Peter C. Gray,et al.  Methyl radical reactions with ethanol and deuterated ethanols , 1968 .

[33]  K. M. Bansal,et al.  Free-radical chain reactions in the radiation-sensitized pyrolysis of ethanol vapor , 1968 .

[34]  A. Kato,et al.  Reaction of oxygen atoms with ethanol , 1967 .

[35]  J. Barnard,et al.  The pyrolysis of ethanol , 1960 .

[36]  L. Crocco,et al.  Kinetics and Mechanism of Ethylene Oxide Decomposition at High Temperatures , 1959 .

[37]  G. Freeman.  The thermal decomposition of diethyl ether. V. The production of ethanol from diethyl ether and the pyrolysis of ethanol , 1958, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[38]  C. Cullis,et al.  The gaseous oxidation of aliphatic alcohols. I. Ethyl alcohol: the products formed in the early stages , 1956, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[39]  A. Gordon,et al.  Studies of Diffusion Flames. II. Diffusion Flames of Some Simple Alcohols. , 1956 .