The invention discloses a
flue gas low-temperature combined desulfurization and denitration technology method mainly including the steps:
flue gas after dedusting having a purification temperature and
humidity meeting desulfurization conditions is sent into a desulfurization
tower to flow through a desulfurization catalyst
bed,
sulfur dioxide in the
flue gas is oxidized into
sulfur trioxide under the action of a catalyst, and
sulfur trioxide acts with water in the
flue gas to generate
sulfuric acid; the desulfurization catalyst
bed is regenerated through progressively-decreased
sulfuric acid concentration gradient washing; the
flue gas after desulfurization is sent into a denitration conditioning work section, is dehumidified and heated, and is adjusted to meet requirements of a denitration technology; the
flue gas after dehumidification and heating is sent into a mixing
tower and is mixed with injected
ammonia gas, the mixed flue gas mixed with the
ammonia gas is sent into a denitration
tower to flow through a denitration catalyst
bed, and
NOx, NH3 and O2 in the mixed flue gas are converted into N2 and water under the action of a denitration catalyst. The problems that a conventional
flue gas desulfurization and denitration technology is narrow in flue gas applicable scope, high in
heating energy consumption, high in running cost and the like are overcome.