The thermal decomposition of methyl chloride in hydrogen/oxygen mixtures and argon bath gas was carried out at I atmosphere pressure in tubular flow reactors. CH,CI, intermediate, and final products were analyzed over the temperature range 1098 to 1273 K, with average residence times of 0.2 to 2.0s.A detailed kinetic reaction mechanism based upon fundamental thermochemical and kinetic principles, Transition State Theory and evaluated literature rate constant data was developed to explain and understand the data. The model results show good fits to methyl chloride, intermediate, and final products species profiles with both temperature and time of reaction. The model also fits the data on HCI inhibited oxidation of CO presented in the companion paper by Roesler et al. Reactions showing high sensitivity to inhibitionof CO oxidation were identified. The results indicate that the reaction OH + HCI -H,O + Cl is an important source of OH loss. This decrease in OH strongly effects CO burnout. The reactions of CO + HO, -CO, + OH and CO + ClO -CO, + CI become important pathways for production of CO 2 in the fuel rich system when high levels of HCl are present. The termination reaction CI + H0 2 _ HCI + 0, is also important to inhibition in the lower temperature regime of this study. We also report on CIO radical reactions with methyl and chloromethyl radicals which form formaldehyde and chlorofonnaldehydes that are important to CO formation.

There are two different carbon sites in C2H3Cl where OH addition or abstraction reactions can occur, α and β to the Cl atom, with several dissociation and isomerization products of each addition adduct. Thirteen elementary reactions and 18 species are included in the analysis of this reaction system. Thermochemical kinetic parameters are developed for each elementary reaction process. Chemical activation kinetic analysis with multifrequency QRRK theory for k(E) and master equation for falloff are used to estimate overall rate constants as functions of temperature and pressure. Thermodynamic parameters, including ΔH f°298, S°298, and C p°(T) (300 ≤ T/K ≤ 1500), of stable species are from the literature when available or estimated by the group additivity method. Values for CHClOHĊH2 are determined by density functional calculation and isodesmic reactions. Results are compared with the experimental data. Rate constants (300∼2000 K, in cm3 mol-1 s-1, E a in cal/mol) for the important addition and abstraction channels at 760 Torr are as follows:  k = 1.22 × 1084 T -25.5 exp(−15000/RT) for C2H3Cl + OH → CHClOHĊH2; k = 1.77 × 1040 T -9.08 exp(−7240/RT) for C2H3Cl + OH → ĊHClCH2OH; k = 9.72 × 106 T 2 exp(−3800/RT) for C2H3Cl + OH → CH2ĊCl + H2O; k = 1.69 × 107 T 2 exp(−4390/RT) for C2H3Cl + OH → ĊHCHCl + H2O.

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