TREATMENT SYSTEM FOR MERCURY IN FLUE GAS

摘要

The present invention is a removal system for mercury in the flue gas configured to remove Hg contained in a flue gas flowing from a boiler, and includes: a heat exchanger configured to execute heat exchange for a flue gas flowing from a boiler; a precipitator configured to remove soot dust in the flue gas; a wet SOx removal unit configured to remove mercury oxide Hg2 + in the flue gas by alkali absorbent and desulfurize sulfur oxide in the flue gas; and an HBr compound supply unit configured to supply HBr, namely, a Br compound into a flue gas duct configured to discharge a flue gas from a boiler outlet. Further, enrichment of bromine contained in the alkali absorbent inside the wet SOx removal unit is set to predetermined enrichment or higher.

主权项

1. A treatment system for mercury in a flue gas, which is a system to remove Hg contained in the flue gas flowing from a boiler, comprising:
an NH4Cl solution supply unit configured to supply an NH4Cl solution to the flue gas discharged from the boiler; an NOx removal unit provided with a denitrification catalyst configured to denitrate NOx in the flue gas and oxidize metal mercury (Hg0); a heat exchanger configured to execute heat exchange for the flue gas flowing from the boiler; a precipitator configured to remove soot dust in the flue gas; a wet SOx removal unit configured to remove mercury oxide Hg2− in the flue gas with alkali absorbent and also desulfurize sulfur oxide in the flue gas; and a Br compound supply unit configured to supply a Br compound into the flue gas or into the alkali absorbent of the wet SOx removal unit, wherein enrichment of bromine inside the alkali absorbent in the wet SOx removal unit is set to predetermined enrichment or higher.