Preliminary Study on Oxidation of Elemental Mercury in the Presence of Gaseous Oxidants

Elemental mercury in coal-fired flue gas is difficult to be removed efficiently by traditional Air Pollution Control Devices (APCD). It has been proved to a promising approach to convert elemental mercury to oxidized mercury, which is soluble and ready to be captured. The oxidants for the direct oxidation of elemental mercury by gas phase reaction were studied, and gaseous iodine was investigated in this paper. The reaction kinetics between elemental mercury and oxidants were determined experimentally. Iodine showed high performance to the oxidation of elemental mercury among these oxidants, and the 2^nd rate constant was about 1.95times10^-16cm³-molecules^-1ldrs^-1 at around 297 K. In addition, sulfur dioxide had very slight impact on the reaction kinetics between elemental mercury and iodine. However, nitric oxide showed a significant inhibition effect on this reaction.