H + C2H4 (+M) -> C2H5 (+M)

k_o = 6.00E+41 T^(-7.62) exp(-6970 cal/mol /RT) cm^6/mol^2 s

k_inf = 5.40E+11 T^0.45 exp(-1820 cal/mol /RT) cm3/mol s

F_cent = (1-0.975) exp(-T/210) + 0.975 exp(-T/984) + exp(-4374/T)

Third-body efficiencies:

N2                    1.0 
H2     Enhanced by    2.0 
H2O    Enhanced by    6.0 
CH4    Enhanced by    2.0 
CO     Enhanced by    1.5 
CO2    Enhanced by    2.0 
C2H6   Enhanced by    3.0 
AR     Enhanced by    0.7
SOURCE:
Extended the temperature range, using an RRKM fit, of the decomposition rate coefficient expressions and results of Feng et al. (1993) and Henning-Lee et al. (1993), and converted the resulting expressions to reverse reaction rate coefficients using the GRI-Mech thermochemistry. The k_inf parameters are from Feng et al. (1993) and Henning-Lee et al. (1993) and the k_o expression extends their fit above 1100 K using a calculation based on the method of Troe (1977).

Parameters for the k_o and F_cent extension calculation:
delta-E(0 K) = 2.3 kcal/mol
delta-H(0 K) = -37.5 kcal/mol
<delta E> = 0.40 kcal/mol
The Lennard-Jones parameters: sigma (C2H5-N2) = 4.12 A, epsilon = 124 K
I+/I = 1.1
v = 3112, 3033, 2987, 2920, 2840, 1460, 1440, 1430, 1370, 1175, 1138, 948, 713, 540 cm^(-1)

COMMENTS:
Results for decomposition direction k_o (cm3/mol s)
T(K)3005008001200
GRI-Mech 6.9E-9 4.1E2 1.3E8 4.3E10
Feng et al. (1993) 1.3E-9 4.5E2 1.5E8 8.9E10

Served as an optimization variable in GRI-Mech 1.2 and 2.1 releases. The rate coefficient was not changed.

Served as an optimization variable for GRI-Mech 3.0 and was multiplied by 0.50 in the optimization.

The pressure broadening is expressed in the Troe form.

REFERENCES:
Feng et al. (1993)
Feng, Y., Niiranen, J.T., Bencsura, A., Knyazev, V.D., Gutman, D., and Tsang, W. (1993) J. Phys. Chem. 97, 871.
Henning-Lee et al. (1993)
Henning-Lee, M.A., Green, N.J.B., Pilling, M.J., and Robertson, S.H. (1993) J. Phys. Chem. 97, 860.
Troe (1977)
Troe, J. (1977) J.Chem.Phys. 66, 4745. 
                        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       -20.8       -36.3    2.31E+11    1.24E-15    1.94E+26
     500       -22.3       -36.9    6.05E+11    8.35E-05    7.24E+15
    1000       -23.9       -38.0    1.62E+11    1.64E+03    9.90E+07
    1500       -24.4       -38.6    1.84E+10    7.60E+04    2.41E+05
    2000       -24.7       -39.0    3.05E+09    2.46E+05    1.24E+04
    2500       -24.8       -39.3    6.95E+08    3.23E+05    2.15E+03
    3000       -24.8       -39.5    1.96E+08    2.85E+05    6.90E+02
______________________________________________________________________


                        PRESSURE = 1 atm N2    
______________________________________________________________________
    Temp      delta-S     delta-H      kf          kr         Keq     
     (K)    (cal/mol K)  (kcal/mol) ----(mol,cm3,s)-----   (cm3/mol)  
______________________________________________________________________
                                                                      
     300       -20.8       -36.3    3.12E+11    1.61E-15    1.94E+26
     500       -22.3       -36.9    1.12E+12    1.55E-04    7.24E+15
    1000       -23.9       -38.0    7.15E+11    7.25E+03    9.90E+07
    1500       -24.4       -38.6    1.33E+11    5.50E+05    2.41E+05
    2000       -24.7       -39.0    2.55E+10    2.06E+06    1.24E+04
    2500       -24.8       -39.3    6.25E+09    2.91E+06    2.15E+03
    3000       -24.8       -39.5    1.84E+09    2.67E+06    6.90E+02
______________________________________________________________________


                        PRESSURE = 10 atm N2   
______________________________________________________________________
    Temp      delta-S     delta-H      kf          kr         Keq     
     (K)    (cal/mol K)  (kcal/mol) ----(mol,cm3,s)-----   (cm3/mol)  
______________________________________________________________________
                                                                      
     300       -20.8       -36.3    3.27E+11    1.69E-15    1.94E+26
     500       -22.3       -36.9    1.34E+12    1.85E-04    7.24E+15
    1000       -23.9       -38.0    1.95E+12    1.97E+04    9.90E+07
    1500       -24.4       -38.6    6.35E+11    2.63E+06    2.41E+05
    2000       -24.7       -39.0    1.76E+11    1.42E+07    1.24E+04
    2500       -24.8       -39.3    5.15E+10    2.39E+07    2.15E+03
    3000       -24.8       -39.5    1.64E+10    2.38E+07    6.90E+02
______________________________________________________________________
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