Review on Mercury Removing Technologies Using Photooxidation Reaction
Mercury control technologies of flue gas would be one of important environmental protection issues in the coal-fired power plant.The reaction mechanism of photooxidation reaction for mercury removal technologies were analyzed,including photochemical oxidation reaction and photocatalytic oxidation reaction.In the photochemical oxidation reaction,the ground state atom or free radicals with strong oxidation were produced and difficult removable Hg0 was oxidized to Hg with higher valence under the irradiation of UV light,and Hg with higher valence could be trapped by the following electrostatic precipitator and removed.In the photochemical oxidation reaction,the oxidation of mercury need the participation of O2 and H2O in the flue gas,while the reactions occur under the catalysis of photocatalysts such as TiO2 or TiO2 supported complex in the photocatalytic oxidation reaction.The research development of photooxidation reaction was elaborated.The mercury removal rate could reach 60%~70% for photooxidation reaction technology,with simple equipment and no secondary pollution.