SYSTEM FOR REMOVING MERCURY AND METHOD OF REMOVING MERCURY FROM MERCURY-CONTAINING HIGH-TEMPERATURE DISCHARGE GAS

A mercury reduction system 10A according to the present embodiment is a mercury reduction system that reduces NOx and Hg in flue gas 12 discharged from a boiler 11, and includes an NH 4 Cl supplying unit 15A that sprays an NH 4 Cl solution 14 into a flue 13 of the boiler 11, a reduction denitration apparatus 16 that includes a denitration catalyst for reducing NOx in the flue gas 12 with NH 3 and oxidizing Hg in the presence of HCl, and a wet desulfurization apparatus 20 for reducing Hg oxidized in the reduction denitration apparatus 16 with limestone-gypsum slurry 19. The NH 4 Cl supplying unit 15A includes an NH 4 Cl solution feed pipe 33 that supplies the NH 4 Cl solution 14 into the flue 13 in a liquid state, a blow pipe that is inserted into the flue 13 so as to surround the NH 4 Cl solution feed pipe 33 and through which air 34 is injected into the flue 13, and a two-fluid nozzle 37 that is fitted to an end of the NH 4 Cl solution feed pipe 33 and through which the NH 4 Cl solution 14 is injected. Through the two-fluid nozzle 37, the NH 4 Cl solution 14 is injected and sprayed in fine liquid droplets.