| 摘要 |
Disclosed is an Hg removal system which removes Hg contained in flue gas (12) from a boiler (11), in which the Hg removal system includes an ammonium chloride solution supply means (a reduction oxidation assistant supply means) (16) that sprays an NH 4 Cl solution (14), which contains ammonium chloride as a reduction oxidation assistant, into a flue gas duct (13) that is in the downstream of the boiler (11), a reduction denitration device (a reduction denitration means) (17) that contains a denitration catalyst which reduces NOx in the flue gas (12) with an NH 3 gas, while oxidizing metallic mercury (Hg 0 ) in the coexistence of an HCl gas, a heat exchanger (18) that performs heat exchange of the denitrated flue gas (12), a precipitator (19) that removes soot and dust in the denitrated flue gas (12), a wet desulfurization device (21) that removes divalent Hg 2+ , which is oxidized in the reduction denitration device (17), using a limestone and gypsum slurry (an alkali absorbent) (20), and a removal assistant supply means (23) that supplies a removal assistant (22) for removing impurities into the limestone and gypsum slurry (20) that circulates through the wet desulfurization device (21). |
