C0-C2 Reactions DataBase

Construction of this database

Every unimolecular and bimolecular elementary forward reaction involving the reacting species considered have been systematically written, except for reactions leading to C2+ free radicals (containing more than two carbons atoms) which were not written, because C2+ free radicals consumption reactions were not considered. To ensure this reaction base to be as comprehensive as possible, it was built by using a reaction grid, as proposed by Tsang et al. (Tsang, W., and Hampson, R.F., J. Phys. Chem. Ref. Data, 15, n°3 (1986)). The relevant reverse reactions were taken into account in all the cases, except for the forward reactions leading to three products.

Reacting species include 42 compounds(molecules and radicals) which have been ranked according to the molecular formula OxCyHz (with x varying from 0 to 3, y from 0 to 2 and z from 0 to 6) : H, H2, C, CH, CH2 (singlet), CH2 (triplet), CH3, CH4, C2H, C2H2, C2H3, C2H4, C2H5, C2H6, O, OH, H2O, CO, CHO, CH2O, CH3O, CH2OH, CH3OH, HCCO, CH2CO, CH3CO, CH2CHO, CH3CHO, C2H4O (epoxyde), C2H5O, C2H5OH, O2, HO2, H2O2, CO2, CH3O2, CH3O2H, C2H5O2, C2H4O2H, C2H5O2H, CH3CO3 and CH3CO3H (peracide). This ranking permits to separate easily the part of the mechanism related to pyrolysis reactions which is located at the beginning of the file, from the other reactions.

Products include 15 stable species containing 3 or 4 carbon atoms: C3H4, C3H6, C3H8, C4H2, C4H4, C4H6, C4H8, n-C4H10, C2H3CHO, C2H5CHO, n-C3H7OH, CH3COCH3, C2H5COCH3, CH3COCHO and CH3COCOCH3, and the glycol CH2OH-CH2OH.

The mechanism includes 396 reversible reactions and 43 irreversible reactions, involving as reactants 24 free radicals and 18 molecules.

Thermochemical and kinetic data
Except for biradicals (CH2 (singlet), CH2 (triplet), O and CO) for which the coefficients of the CHEMKIN II thermochemical library (R.J. Kee, F.M. Rupley and J.A. Miller - Sandia Laboratories Report, SAND 89 - 8009B (1993)) are used, specific heats, heats of formation and entropies of molecules or radicals are the data calculated by the software THERGAS.

The associated kinetic data were taken from the literature and are mainly those proposed by Baulch et al. (Baulch, D.L. , Cobos, C.J., Cox, R.A., Franck, P. , Hayman, G.D., Just, Th., Kerr, J.A., Murrells, T.P., Pilling, M.J., Troe, J., Walker, R.W., and Warnatz, J.,Comb. Flame, 98: 59 (1994)) and Tsang and Hampson. The pressure dependent rate constants are expressed by using the formalism proposed by Troe.

Validation
The reaction base was validated by simulating results obtained in our laboratory on the oxidation of methane and ethane in a jet-stirred reactor in a temperature range from 773 to 1573K and on methane-oxygen auto-ignition delays in shock tube.

Methane oxidation at 1073 K, P=1atm, for mixtures : Helium, Hydrocarbon, Oxygen = 10 : 1 : 1 (mole). Points show experiments and lines simulations.	Mixtures : Argon, Hydrocarbon, Oxygen = 89.05: 3.65: 7.30 (mole). Points show experiments and the line simulations.

Relevant Publications

Mechanism file: this file includes reactions and the associated thermochemical and kinetic data and is usable by CHEMKIN II (Sandia National Laboratories).

Please send us feedback of your experience at using this database : Frederique.Battin-Leclerc@ensic.inpl-nancy.fr