Conversion of elemental mercury with a novel membrane catalytic system at low temperature.

A unique assembly, which integrated membrane delivery for oxidants with catalytic oxidation (MDCOs), was employed to convert elemental mercury (Hg(0)) to its oxidized form at low temperature (around 150 °C). MnO(x) was used as the main catalytic component in MDCOs with Mo and/or Ru to improve the catalytic activity. The MDCOs was proved to be very effective for the conversion of Hg(0) compared with the traditional catalytic oxidation mode (TCO). The analysis of speciation for Hg after catalytic oxidation showed that there was mainly mercury (II) chloride. The addition of transition metals of Mo and Ru obviously improved the conversion of Hg(0) to Hg(2+) and enhanced the activity of the MDCOs at low temperature, and the conversion efficiency of Hg(0) reached 95% with Mo-Ru-Mn catalyst and 8 ppmv HCl. The inhibition of SO(2) to Hg(0) conversion in the MDCOs was insignificant. The Hg(0) removal exceeded 80% even if the concentration of SO(2) reached 1000 ppmv. The results also indicated that the Deacon reaction with the yield of Cl(2) were significantly improved after modified, and MDCOs with Mo-Ru-Mn catalyst can work efficiently at low temperature.