Chapter 2 - Reduction of dioxins and furans in incineration

Abstract

This chapter examines the effects of oxygen enrichment of combustion air on the incinerator operational and environmental performances. The molecular electrostatic potentials were used as a tool to characterize the relative stabilities and reactive properties of a number of halogen substituted dibenzo-p-dioxins (“dioxins”) and dibenzo-furans (“furans”). Tests were done in two different configurations: second grate primary air enrichment and second and third grate primary air enrichment. In both configurations, the flue gas volume was kept constant. Standard gas analyses were performed in the boiler and the stack. Dioxins and furans samplings were done in the stack for six hours per sample. The analyses of the collected samples were done subsequently by the GC–MS technique. The result obtained during the tests on the incinerator was that the average dioxins and furans emissions were decreased by a factor of 3 when oxygen enrichment was used. The mechanisms of dioxins and furans formation observed were that the formation of propargyl radicals was an important pathway for their synthesis.