CATALYTIC DESTRUCTION OF PCDDS PCFFS IN MUNICIPAL SOLID-WASTE FLUE-GAS

Catalytic destruction technology was applied to reduce PCDDs/PCDFs concentration levels in the flue gas from a municipal solid waste incinerator. Using common combustion techniques, high temperatures (> 1000-degrees-C) are required to decompose PCDDs/PCDFs. However, from an energy saving perspective, it is more efficient to perform exhaust gas cleanup at low temperatures because the incinerator flue gas temperatures are comparatively low after leaving the waste heat boiler and air pollution control unit (250-300-degrees-C). The ability to remove PCDDs/PCDFs by catalytic destruction was previously confirmed by the authors, with the presented study conducting pilot plant experiments using exhaust gas (max. 1900 N m3/hr) induced from the outlet of the electrostatic precipitator of a municipal solid waste incinerator. A PCDDs/PCDFs destruction ratio of at least 99% was obtained at temperatures less than 300-degrees-C, being dependent on space velocity and the catalyst geometric properties.