This project addresses the formation of pollutants (other than dioxins and furans) in the cool zone--the region downstream from the flame in a combustor where radical quenching and surface catalysis are the dominant modes of reaction. A dual-chamber reactor is used in which the first chamber houses a diffusion flame and the second chamber (simulating the cool zone) can be configured to study gas-phase reactions, wall and surface effects, or catalysis by entrained particles. Effluents from both chambers are analyzed by gas chromatography. The study uses methane as a fuel pure and doped with ethylene, benzene or trichlorobenzene. Dopants can also be added to the effluent of the combustor, hydrogen chloride, nitrogen oxides, and water are used. Surfaces studied include silica, solica doped with copper oxide or iron oxide, a model fly ash, and real fly ashes from a municipal solid-waste incinerator and a coal combustor.
This effort provides fundamental data on formation of pollutants and provides a rational basis for strategies to reduce pollutant emissions from incinerators, power and heating plants, and industrial operations.