Combustion exhaust gas treatment system

摘要

Five combustion exhaust gas treatment systems capable of removing dust and selenium (Se) in combustion exhaust gas and making it harmless are proposed: (1) the combustion exhaust gas is cooled to 350 DEG C or less, the dust is separated, the Se is transformed into an insoluble compound, and Se is separated; (2) combustion exhaust gas is cooled to 350 DEG C or less, the dust is separated, Se elution preventive agent is added, and the dust is formed into scale; (3) dust in the combustion exhaust gas is collected by a dry dust collector, the dust is formed into a slurry by making use of part of the circulation liquid in an desulfurization apparatus, and tetravalent Se in the dust slurry is transformed into an insoluble compound, which is separated into solid and liquid; (4) dust is separated from combustion exhaust gas by a dust collector and is heated to gasify Se, and is introduced into desulfurization apparatus, etc., and formed into a slurry, and the Se is transformed into an insoluble compound; and (5) a treating agent for making tetravalent Se insoluble is added to a part of the circulation liquid in a desulfurization apparatus, and is sprayed into combustion exhaust gas to make Se insoluble. <IMAGE>