Simultaneous removal of multi-pollutants from flue gas by a vaporized composite absorbent.

An economical process that was used to remove SO2, NO and Hg0 simultaneously was developed, based on the pre-oxidations of Hg0 and NO by a vaporized Fenton-based complex oxidant (FO) consisted of Fenton and NaClO. The effects of concentrations of FeSO4 and NaClO in the oxidant, the molar ratio of vaporized oxidant to multi-pollutant, the oxidant solution pH, the reaction temperature, the gas flow ratio of vaporized FO to multi-pollutants, the flue gas flow and the concentrations of coexistence gases in flue gas on the simultaneous removals were investigated experimentally. The results showed that the removals of NO and Hg0 were significantly depended on FeSO4 and NaClO concentrations, the molar ratio of vaporized oxidant to multi-pollutants, the FO solution pH, the reaction temperature, the gas flow ratio of vaporized FO to multi-pollutants and flue gas flow. And higher concentration of SO2 and an appropriate concentration of NO had the promotion for Hg0 removal. The average simultaneous removal efficiencies of 100% for SO2, 81% for NO and 91% for Hg0 were obtained under the optimal reaction conditions. According to the characterization of the reaction removal products by SEM, EDS, XRD and AFS, the reaction mechanism was speculated.