Abstract
An experimental study of C1 and C2 hydrocarbon species in the post-flame zones of fuel-rich ethylene-air flames at atmospheric pressure and temperatures from 1700 to 1940 K is reported. Most hydrocarbon oxidation occurs via
C2H2 + OH. → ((CH2CO + H) (Rl)
Reaclion (Rl) is effectively irreversible under post-flame conditions. Based on this study and other post-flame and shock-lube studies, the rate constant for (Rl) is, independent of pressure,
k1 = 1.1 × 1013 exp (−30000Jmol−1RT)cm3 mol−11 s−1
with an estimated uncertainty factor less than 2 in the temperature range 1650 to 1950 K. Oxidation of ketene and CH3 by OH also occurs to some extent. The reaction
CH3 + OH → (CH2OH + H) (R2)
is very fast, with k2 ⩾1.50 × 1013 cm3 mol −1 s−1 A new mode of C1/C2 interaction is found to be important under richer conditions:
CH2CO + CH3 → (C2H5 + CO) (R6)
The occurence of (R6) limits the formation of C1, species.
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