On mechanisms of formation of environmentally harmful compounds in homogeneous combustors

A kinetic model is developed for calculating the emission characteristics of homogeneous combustors using methane and synthesis gas (syngas) as a fuel. The model is validated over a large set of experimental data on concentrations of NO, CO, and OH in laminar flames and in the Bunsen burner and on concentrations of OH, NO, and CO in a homogeneous combustor operating on a mixture of syngas with air. At an identical temperature of combustion products, i.e., identical thermodynamic efficiency, the combustor operating on syngas is demonstrated to emit a greater amount of NO, CO, and CO$_2$, as compared with the combustor operating on methane. Though the use of syngas allows one to organize stable combustion of ultralean mixtures and to obtain extremely low concentrations of NO and CO at the combustor exit ($\approx$ 1–3 ppm), the amount of CO$_2$ in the exhaust of even extremely lean mixtures ($\alpha\approx$ 3) is appreciably greater than that in the case of using methane.