The invention relates to a
system for simultaneous desulfurization-
denitrification-demercuration based on a combination of free radical pre-oxidation and wet absorption. The
system adopts the structure that
ultraviolet light and a catalyst are combined to decompose a
peroxide; during
decomposition, strong oxidative hydroxy or
sulfate radical free radical are generated for oxidative removal of SO2,
NOx and Hg0 in an
impact bed; part of
flue gas from an emission source and part of catalyst particles are mixed and sprayed into the
impact bed through high-speed nozzles, and the other part of
flue gas and catalyst particle are mixed and sprayed into the
impact bed through the high-speed nozzles which are coaxially arranged in an opposite manner; meanwhile, a
peroxide solution is sprayed into the impact bed through sprayers, so that such three gas steams are subjected to impact and mixing in the impact bed. The
system has the advantages that the
ultraviolet light and the catalyst are combined to decompose the
peroxide, strong oxidative hydroxy or
sulfate radical free radical are generated for oxidation of SO2,
NOx and Hg0, so that gas-sate
divalent mercury,
nitrogen dioxide,
sulfur trioxide,
sulfuric acid and
nitric acid are generated, and then SO2,
NOx and Hg0 are removed in a wet desulfurization system at the
tail part. Therefore, the system provided by the invention can be used for transforming the conventional
coal burning boiler to achieve
sulfur-
nitrogen-mercury integrated removal, and has a broad market application prospect.