Iron compound catalyst for inhibiting generation of dioxin

Abstract

An iron compound catalyst for inhibiting the generation of dioxin contains iron oxide particles, iron oxide hydroxide particles or mixed particles having a catalytic activity capable of converting not less than 15% of carbon monoxide into carbon dioxide when 2.8×10−4 mol of iron oxide particles obtained by heat-treating the iron compound catalyst in air at a temperature of 800° C. for 15 minutes, are instantaneously contacted with 6.1×10−7 mol of carbon monoxide at a temperature of 250° C. at a space velocity (SV) of 42,400 h−1 in an inert gas atmosphere using a pulse catalytic reactor, the iron oxide particles or the iron oxide hydroxide particles have an average particle size of 0.01 to 2.0 &mgr;m, a BET specific surface area of 0.2 to 200 m2/g, a phosphorus content of not more than 0.02% by weight, a sulfur content of not more than 0.6% by weight and a sodium content of not more than 0.5% by weight. This iron compound catalyst enables complete combustion of municipal solid waste and decomposition of dioxin precursors even at a low combustion temperature in intermittently operated incinerators such as mechanical batch incinerators or semi-continuous incinerators, and can inhibit dioxin generation of due to a memory effect upon low-temperature combustion at the start-up or shut-down of the incinerators, without large-scale incinerator renovation or plant and equipment investment.