The kinetics of the combustion of trichloroethylene for low Cl/H ratios

A kinetic model has been developed for the combustion of trichloroethylene (TCE) under low Cl/H ratio conditions. Flame species concentration profiles, measured for CH₄/O₂/Ar flames, reveal that the most important reaction channels in the decomposition of TCE in the CH₄/TCE/O₂/Ar flame are the displacement by H atoms of Cl atoms from TCE, 1,1-dichloroethylene (DCE), and vinyl chloride. The displacement of Cl atoms from TCE by OH also contributes to the decomposition of TCE, and leads to the production of 2,2-dichloroethenol, a species unobserved in previous flame studies. Other species found in large concentrations in the present CH₄/TCE/O₂/Ar flames, but not observed in previous TCE/O₂/Ar flame studies at higher chlorine-to-hydrogen ratios, are ketene, chloroketene, and dichloroketene. Finally, the presence of TCE catalyzes the formation of C₃-C₆ hydrocarbons. The presence of significant concentrations of C₃H₃, C₃H₄, and C₆H₆ is consistent with `odd carbon species' mechanisms previously suggested for benzene formation in hydrocarbon flames.