Gaseous Elemental Mercury Removal Using Combined Metal Ions and Heat Activated Peroxymonosulfate/H2O2 Solutions.

Several novel oxidation removal processes of elemental mercury (Hg0) from flue gas using combined Fe2+/Mn2+ and heat activated peroxymonosulfate (PMS)/H2O2 solutions in a bubbling reactor were proposed. The operating parameters (e.g., PMS/H2O2 concentration, Fe2+/Mn2+ concentration, solution pH, activation temperature, and Hg0/NO/SO2/O2/CO2 concentration), mechanism and mass transfer‐reaction kinetics of Hg0 removal were investigated. The results show that heat and Fe2+/Mn2+ have significant synergistic effect for activating PMS and PMS/H2O2 to produce free radicals to oxidize Hg0. Hg0 removal is strongly affected by PMS/H2O2 concentration, Fe2+/Mn2+ concentration, activation temperature, and solution pH. SO4−· and ·OH produced from combined heat and Fe2+/Mn2+ activated PMS/H2O2 play a leading role in Hg0 removal. Under optimized experimental conditions, Hg0 removal efficiencies reach 100, 94.9, 66.9, and 58.9% in heat/Fe2+/PMS/H2O2, heat/Mn2+/PMS/H2O2, heat/Fe2+/PMS, and heat/Mn2+/PMS systems, respectively. Hg0 removal processes in four systems belong to fast reaction and were controlled by mass transfer under optimized experimental conditions. © 2018 American Institute of Chemical Engineers AIChE J, 65: 161–174, 2019 [ABSTRACT FROM AUTHOR]