H + CH2 (+M) -> CH3 (+M)

k_inf = 6.00E+14 cm3/mol s

F_cent = (1-0.562) exp(-T/91) + 0.562 exp(-T/5836) + exp(-8552/T)

Third-body efficiencies:

SOURCE:

Two channel RRKM calculations for CH3 decomposition, following the work of Wagner and Harding (1992). (A. F. Wagner, private communication, 1996) The related reactions of this system are 289 CH + H2 (+M) = CH3 (+M), and the chemical activation 126 CH + H2 = H + CH2.

< delta-E> (average energy transferred per collision) = 0.30 kcal/mol
The Lennard-Jones parameters: sigma (CH3-N2) = 3.78 A, epsilon = 103 K
I+/I (used to compute the Waage-Rabinovitch correction for rotational energy) = 6.8
v = 3184, 3184, 3000, 1383, 1383, 580 cm^(-1)

COMMENTS:

At 2500 K, k_o for CH3 decompostion in Ar, 1.1E8 (cm3/mol s), compares to the shock tube measurement of 1.9E8 (cm3/mol s) by Markus et al. (1992), and 1.2E8 by Lim and Michael (1994) in Kr.

The pressure broadening is expressed in the Troe form.

Served as an optimization variable in the GRI-Mech 1.2 and 2.1 releases, where the rate coefficient using a different expression was not changed. Served as an optimization variable in version 3.0 and was not changed.

REFERENCES:

Lim and Michael (1994)

Lim, K.P., and Michael, J.V. (1994) 25th Symposium (International) on Combustion, p. 713.

Markus et al. (1992)

Markus, M.W., Woiki, D., and Roth P. (1992) 24th Symposium (International) on Combustion, p. 581.

Troe (1977)

Troe, J. (1977) J.Chem.Phys. 66, 4745.

Wagner and Harding (1992)

Wagner, A.F., and Harding, L.B. (1992) ACS Symp. Ser. 502, 48.

                        PRESSURE = 0.1 atm N2  
______________________________________________________________________
    Temp      delta-S     delta-H      kf          kr         Keq     
     (K)    (cal/mol K)  (kcal/mol) ----(mol,cm3,s)-----   (cm3/mol)  
______________________________________________________________________
                                                                      
     300       -27.5      -110.8    3.60E+12    3.07E-67    1.17E+79
     500       -29.5      -111.5    1.55E+12    1.88E-35    8.25E+46
    1000       -31.2      -112.7    2.61E+11    4.84E-12    5.39E+22
    1500       -31.6      -113.2    7.45E+10    1.56E-04    4.79E+14
    2000       -31.6      -113.3    2.89E+10    6.05E-01    4.78E+10
    2500       -31.6      -113.2    1.36E+10    6.80E+01    2.00E+08
    3000       -31.5      -113.0    7.27E+09    1.35E+03    5.40E+06
______________________________________________________________________


                        PRESSURE = 1 atm N2    
______________________________________________________________________
    Temp      delta-S     delta-H      kf          kr         Keq     
     (K)    (cal/mol K)  (kcal/mol) ----(mol,cm3,s)-----   (cm3/mol)  
______________________________________________________________________
                                                                      
     300       -27.5      -110.8    3.00E+13    2.57E-66    1.17E+79
     500       -29.5      -111.5    1.37E+13    1.66E-34    8.25E+46
    1000       -31.2      -112.7    2.44E+12    4.52E-11    5.39E+22
    1500       -31.6      -113.2    7.06E+11    1.47E-03    4.79E+14
    2000       -31.6      -113.3    2.76E+11    5.78E+00    4.78E+10
    2500       -31.6      -113.2    1.31E+11    6.53E+02    2.00E+08
    3000       -31.5      -113.0    7.01E+10    1.30E+04    5.40E+06
______________________________________________________________________


                        PRESSURE = 10 atm N2   
______________________________________________________________________
    Temp      delta-S     delta-H      kf          kr         Keq     
     (K)    (cal/mol K)  (kcal/mol) ----(mol,cm3,s)-----   (cm3/mol)  
______________________________________________________________________
                                                                      
     300       -27.5      -110.8    1.45E+14    1.24E-65    1.17E+79
     500       -29.5      -111.5    8.58E+13    1.04E-33    8.25E+46
    1000       -31.2      -112.7    2.02E+13    3.75E-10    5.39E+22
    1500       -31.6      -113.2    6.28E+12    1.31E-02    4.79E+14
    2000       -31.6      -113.3    2.52E+12    5.27E+01    4.78E+10
    2500       -31.6      -113.2    1.21E+12    6.05E+03    2.00E+08
    3000       -31.5      -113.0    6.57E+11    1.22E+05    5.40E+06
______________________________________________________________________

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