Radical-poor combustion

High-temperature hydrocarbon combustion is a complicated chemical process. Nevertheless, it is possible to discern some features common to all fuels. To discuss them, it is convenient to separate the treatment of radical-poor and radical-rich situations. The former are characteristic of ignition processes, studied in the laboratory mainly by shock-wave initiation, while the latter are found in fully developed flames, studied in the laboratory in burner-stabilized flames. The elementary reactions important in these two situations are in part the same, but in part different. 

A great variety of organic combustion products have been identified (Schumacher et al., 1977 Junk and Ford, 1980 Hawthorne et al., 1988). The mechanisms of the reaction of oxygen with combustible species are, however, very poorly understood. Even such a simple fuel molecule as methane has very complex behavior during combustion. The methyl free radical formed during the initiation step has a number of possible fates including recombination to form ethane (Equation 4.68), common in fuel-rich flames ... 

---