Dioxin Emission Control With an Iron Oxide Incineration Catalyst

摘要

An incineration catalyst has been used to reduce and destroy dioxins emitted from municipal and industrial waste incinerators. The synthetic iron oxide catalysts were an acicular goethite (α-FeO(OH)) and an acicular hematite (α-Fe{sub}2O{sub}3) with average particle sizes of 0.25 μm and average specific surface areas of 80-90 m{sup}2/g. The Toda incineration catalyst (TIC) has been injected into the flue gas stream upstream from air pollution control devices (APCD) either as pure TIC or in mixtures with activated carbon and/or slaked lime. TIC particles within the gas stream of the emission control system acted as both a dechlorination and an oxidation catalyst for polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF), as well as their carbonaceous and chlorinated hydrocarbon precursors in the temperature range from 200 °C to 400 °C. TIC co-injected with activated carbon oxidized PCDD and PCDF adsorbed to the activated carbon particles. This paper presents examples of dioxin emission reduction at waste incinerators that use TIC.