Patent ID: 8372363

Claim:
A method for removing mercury in a combustion exhaust gas, comprising: injecting ammonia or urea as a reducing agent into a combustion exhaust gas containing nitrogen oxides, sulfur dioxide, metallic mercury, and hydrogen halides, and then introducing the combustion exhaust gas to a denitration apparatus filled with a denitration catalyst to cause a denitration reaction and oxidize the metallic mercury to produce mercury halide; and introducing the combustion exhaust gas through an air preheater and an electric dust collector to a wet desulfurization apparatus, thereby removing the sulfur dioxide and the mercury halide, wherein an ammonia concentration of the combustion exhaust gas at an exit of the denitration apparatus is maintained at 5 ppm or higher, and the mercury halide is adsorbed or precipitated onto combustion ash and collected by the electric dust collector to discharge the mercury halide out of a system.