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

k_o = 1.20E+42 T^(-7.62) exp(-6970 cal/mol /RT) cm^6/mol^2 s

k_inf = 1.08E+12 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.

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    4.79E+11    2.47E-15    1.94E+26
     500       -22.3       -36.9    1.21E+12    1.67E-04    7.24E+15
    1000       -23.9       -38.0    3.23E+11    3.27E+03    9.90E+07
    1500       -24.4       -38.6    3.67E+10    1.52E+05    2.41E+05
    2000       -24.7       -39.0    6.10E+09    4.92E+05    1.24E+04
    2500       -24.8       -39.3    1.39E+09    6.46E+05    2.15E+03
    3000       -24.8       -39.5    3.92E+08    5.69E+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    6.23E+11    3.21E-15    1.94E+26
     500       -22.3       -36.9    2.24E+12    3.10E-04    7.24E+15
    1000       -23.9       -38.0    1.43E+12    1.45E+04    9.90E+07
    1500       -24.4       -38.6    2.66E+11    1.10E+06    2.41E+05
    2000       -24.7       -39.0    5.10E+10    4.11E+06    1.24E+04
    2500       -24.8       -39.3    1.25E+10    5.82E+06    2.15E+03
    3000       -24.8       -39.5    3.68E+09    5.33E+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    6.54E+11    3.37E-15    1.94E+26
     500       -22.3       -36.9    2.67E+12    3.69E-04    7.24E+15
    1000       -23.9       -38.0    3.90E+12    3.94E+04    9.90E+07
    1500       -24.4       -38.6    1.27E+12    5.25E+06    2.41E+05
    2000       -24.7       -39.0    3.52E+11    2.84E+07    1.24E+04
    2500       -24.8       -39.3    1.03E+11    4.77E+07    2.15E+03
    3000       -24.8       -39.5    3.28E+10    4.76E+07    6.90E+02
______________________________________________________________________
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