排ガス処理システム及び排ガス処理方法

摘要

Provided is an air pollution control system including: a denitration apparatus 12 that is configured to remove nitrogen oxides in a flue gas 18 discharged from a boiler 11; an air heater 13 that is configured to recover heat of the flue gas 18; a precipitator 14 that is configured to remove soot and dust contained in the flue gas 18; a desulfurization apparatus 15 that is configured to remove sulfur oxides contained in the flue gas 18 after dust removal using limestone slurry 20 which is an absorbent; a dehydrator 32 that is configured to recover gypsum 31 from absorbent slurry 30 discharged from the desulfurization apparatus 15; a spray drying apparatus 50 provided with a spray unit 52 that is configured to spray dehydrated filtrate 33 supplied from the dehydrator 32; a flue gas introduction line L 11 through which a branch gas 18a branched from the flue gas 18 is introduced to the spray drying apparatus 50; a flue gas supply line L 12 through which the flue gas 18b from the spray drying apparatus 50 returns to a main flue gas duct; a solid content separator 70 that is provided at the flue gas supply line L 12 and performs a solid-gas separation on solid contents 71 contained in the flue gas 18b; and a kneader 72 that performs kneading and immobilizing treatment on the separated solid contents 71 together with an immobilization aid 73.