Bhaskaran, K.A., Frank, P., and Just, Th. (1980)
High Temperature Methyl Radical Reactions with Atomic and Molecular Oxygen
12th Symposium (International) on Shock Tubes and Waves, 1980, p.503
Abstract
A shock tube together with atomic resonance absorption spectrometry (ARAS) was used to record H- and O-atom concentration profiles at shock temperatures ranging within 1700-2300 K and total concentrations of about 1 to 1.5E-5 mol/cm3. Two sets of experiments were performed.
The first set, under excess O-atom conditions enabled selective study of the reaction (10). The rate constant recently suggested for this reaction is more or less compatible with our results.
The second batch of experiments were undertaken to study the relative importance of the two channels dicussed in literature for the reaction of methyl radical with O2: (156), (155) , and (-57).
From our results, CH3 seems to prefer the route (155)-(-57). This could be clearly deduced from measurement under excess O2 conditions. From the experimental results, a rate constant k(A) was obtained. Incidentally, our results at lower O2 conditions indicated strongly that contribution of reaction (-66) and fast decay of CH3O to CH2O + H was idispensable to get a match with the measured profiles. An Arrhenius plot for this reaction produced a rate constant k(B), shown below. The above mentioned results are analysed and discussed.

REACTION RATE COEFFICIENTS SUGGESTED IN THIS WORK:

GRI-Mech
Number
('-' sign
means
reverse)		 Reaction Rate Coefficient
A T^n exp(-E/RT)		 Temperature
Range
(K)
A
(mol,cm3,s)		 n
(T in K)		 E
(cal/mol)
10 O + CH3 -> H + CH2O 8.0E+13     1700-2300
-50 CH3 + M -> H + CH2 + M 6.1E+15   89220 1700-2300
-54 CH2O + M -> H + HCO + M 1.8E+16   80275 1700-2300
-83 CH2O + M -> H2 + CO + M 8.2E+15   69550 1700-2300
138 CH2 + CH3 -> H + C2H4 2.0E+13     1700-2300
156 CH3 + O2 -> OH + CH2O 5.2E+13   34575 1700-2300
-158* C2H6 (+M) -> CH3 + CH3 (+M) 8.0E+12   70340 1700-2300
A** CH3 + O2 -> O + H + CH2O 7.0E+12   25630 1700-2300
B OH + CH3 -> 2H + CH2O 2.0E+16   27420 1700-2300

* units are s-1; valid for the density 1÷1.5E-5 mol/cm3
** preliminary upper limits