Electrochemical enhancement of high-efficiency wet removal of mercury from flue gas

Electrochemical wet absorption composite system has an excellent potential to remove Hg-0 from flue gas. In this study, ruthenium iridium titanium platinum quaternary composite electrode is used as an anode and titanium electrode is used as the cathode, and KI/I-2 absorption solution is introduced into the electrocatalysis system as an electrolyte to form KI/I-2 electrochemical catalytic oxidation system. The removal rate of Hg-0 in flue gas can be increased to 92.3%. The effects of electrolytic voltage, current, Pt content, I-2 concentration, and the ratio of KI/I-2 on the removal of Hg-0 were discussed. The possible free radicals in the electrochemical cathode, anode, and solution were characterized and tested by XRD, SEM, UV-Vis (detection of H2O2, center dot OH, O-3), and FTIR (detection of IO3-). Combined with experimental data and theoretical derivation, the mechanism of Hg-0 removal from flue gas by electrochemical catalytic oxidation alloy formation wet absorption combined process was studied. The results show that the combined process, which is a promising technology can not only improve the removal efficiency of Hg-0, but also realize the resource recovery of Hg-0 and I-2, and provide a feasibility study for the subsequent regeneration of KI/I-2 absorption solution.