A SYSTEM AND METHOD TO GASIFY AQUEOUS UREA INTO AMMONIA VAPORS USING SECONDARY FLUE GASES

摘要

The present invention is a combustion system employing a urea-to-ammonia vapor reactor system. The urea-to-ammonia reactor housing enclosed in a bypass flow duct that receives a secondary flue gas stream at a split point from a main flue gas stream containing nitrogen oxides (NOx) emanating from a boiler. The bypass flow duct allows the secondary flue gas stream to flow past the enclosed reactor housing where injected aqueous urea in atomized or non-atomized form, is gasified to ammonia vapor. The resulting gaseous mixtures of ammonia, its by-products and the secondary flue gas stream subsequently rejoin the main stream, before the main flue gases are treated through a Selective Catalytic Reduction (SCR) reactor apparatus. A residence time of the secondary stream within the bypass flow duct, which may be increased by a recirculation loop, enables effective conversion of urea to ammonia to be used in the SCR apparatus. WO2011057077A1