DIOXIN DESTRUCTION IN CATALYSTS FOR NOX-REDUCTION (SCR-DENOX)

In 1987 Sweden was the first country in the world to set guidelines for dioxin emissions from waste incinerators with levels of 0,5-2 ng/m3n (toxic equivalents) for existing or small plants and 0,1 ng/m3n for new or large plants. The reason for this decision was emissions lower than 0,1 ng/m3n had been repeatedly measured in Malmo, Sweden, which was and still is equipped with dry scrubber/fabric filter. This technology is regarded as being the best technology available for municipal waste incinerators. Dioxin can also, as most organic compounds, be oxidized either at a high temperature (800 - 1200-degrees-C) or in a catalyst at a low temperature level. Basic investigations of destruction of dioxin in various catalysts have been performed during the past years, mainly in Germany and Japan. Dioxin measurements have also recently been accomplished at a few commercial SCR de NOx-plants in Europe. Dioxin destruction in a SCR de NOxcatalyst will soon be regarded as state of the art.