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 forcombusting fuel at atmospheric pressure. The CFB reactor includes a combustionchamber (14), having a fluidized bed of particles therein, a particleseparator section including one or more consecutive particle separators (16,20), a convection section (22) and a clean gas duct (40) connecting theparticle separator to the convection section. The apparatus also includesmeans (54, 56) for injecting ammonia or its precursor into the flue gases, forreducing NOx therein. The ammonia or its precursor is injected into thecleaned flue gases in the clean gas duct (40) connecting the last separator(20) to the convection section (22), the clean gas duct having a very smalldensity of solid particles therein. The temperature in the clean gas ductbeing sufficient for NOx reducing reactions.