Method and apparatus for reducing NOx emissions in CFB reactors used for combustion of fuel containing large amounts of volatile combustible components

摘要

A method and an apparatus for reducing NOx emissions in CFB reactors used for combusting fuel at atmospheric pressure. The CFB reactor includes a combustion chamber having a fluidized bed of particles therein, a particle separator section including one or more consecutive particle separators, a convection section and a clean gas duct connecting the particle separator to the convection section. The apparatus also includes a device for injecting ammonia or its precursor into the flue gases, for reducing NOx therein. The ammonia or its precursor is injected into the clean gas duct connecting the last separator to the convection section, the clean gas duct having a very small density of solid particles herein. The temperature in the clean gas duct is sufficient for NOx reducing reactions.