Abstract
Experimental structures of two dimethoxymethane/oxygen/argon flames at equivalence ratios of φ = 0.24 and 1.72 have been studied by mass spectrometry. The detected species throughout the flame thickness were H2, CH3, CH4, H2O, C2H2, CO, CH2O, CH3O, O2, Ar, CO2, C2H4O2, and C3H8O2. The aim of this work was to extend an original model for ethylene combustion by building a sub-mechanism taking into account the formation and the consumption of oxygenated species involved in dimethoxymethane oxidation. By using kinetic data from the literature, the authors elaborated a new mechanism containing 480 reactions involving 90 chemical species in order to simulate these dimethoxymethane flames. The mechanism provides numerical results, which are in good agreement with experimental data for all species detected in both flames. Whatever the equivalence ratio of the flame, the two main degradation pathways of dimethoxymethane are the same: CH3OCH2OCH3 → CH3OCH2OCH2 → CH3OCH2 → CH2O and CH3OCH2OCH3 → CH3OCHOCH3 → CH3OCHO → CH3OCO → CH3O → CH2O, with the first being the fastest.
ACKNOWLEDGMENTS
The authors are very grateful to the Ministère de la Région Wallonne (Belgium) for financial support (Visa numbers 06/47214 and 07/47509).
Notes
Note. Units are kcal·mol−1.
Note. Rate constants in the form, AT n exp(−E a /RT) in cm, mol, cal, and K units. The following reactions are not listed in the table: k0 = 2.7E + 38 T−6.30 exp(−3100/T); k∞ = 6.30E + 13; a = 0.2105, T* = 5400, T** = 8370, T*** = 83.5; H2/2.0/ H2O/6.0/ CH4/2.0/ CO/1.5/ CO2/2.0/ C2H6/3.0.
a By analogy with CH3OCH3 (DeMore & Bayes, Citation1999).
b By analogy with CH3OCH2 (Herron, Citation1988).
c By analogy with (C2H5)2O (Herron, Citation1988).
d By analogy with RO (Dagaut et al., Citation2001).
e By analogy with DMM + M (R.427; Daly et al., Citation2001).
f By analogy with CH3HCO (Warnatz, Citation1984b).
g By analogy with CH3HCO (DeMore et al., Citation1997).