The chemistry of chlorine in combustion systems and the gas-phase formation of chlorinated and oxygenated pollutants

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1999.Includes bibliographical references.A major concern during the combustion of chlorinated fuels is the formation of chlorinated organic pollutants, which are potentially dangerous to human health and to the environment. Observed combustion byproducts include suspected carcinogenic and toxic compounds, such as chlorobenzenes, chlorophenols, and polychlorinated dioxins, furans and biphenyls. AH of these pollutants are regulated by US-EPA emission standards. This research studies the conditions which favor the gas-phase formation of these chlorinated byproducts. Under fuel-lean conditions, oxygen and chlorine compete for the available hydrogen to form H2O and HCl respectively. Laboratory reactor experiments show that, at short residence times ( 1100°C), oxygen-rich products of methyl chloride combustion, OH and 0 radicals, generated in the oxidation of the injected fuel, transform significant amounts of HCl to Cl radicals. If the chlorine-containing combustion gas is first cooled to an intermediate temperature (T