Emissions of Nitrogen Oxide From a Circulating Fluidized Bed Boiler - The Influence of Design Parameters

Paper in proceeding, 1988

In a circulating bed of silica sand, char is the principal agent for the reduc­tion of nitrogen oxide. The role of volatiles is not significant. Most features observed can be qualitatively explained as a consequence of the presence of char.In a circulating bed with limestone addition, the oxidation of nitrogen containing volatiles causes an increased emission of nitrogen oxide. This effect can be mitigated by avoiding excess addition of limestone in relation to the sulphur content of the fuel or by arranging the air supply in a suitable way, thus de­creasing the oxidation of ammonia.