Pulsed corona discharge for oxidation of gaseous elemental mercury

Abstract

Positive pulsed corona discharge has been applied for the oxidation of gaseous elemental mercury (Hg-0) from a simulated flue gas. The oxidation of Hg-0 to HgO and HgCl2 can significantly enhance the mercury removal from flue gas. At a gas condition of O-2 (10%), H2O (3%), and N-2 (balance), Hg-0 oxidation efficiency of 84% was achieved at an input energy density of 45 J/l. The presence of NO, however, hinders Hg-0 oxidation due to the preferential reaction of NO with O and O-3. On the contrary, SO2 shows little effect on Hg-0 oxidation due to its preferential reaction with OH. It has been also observed that the HCl in gas stream can be dissociated to Cl and Cl-2 and can induce additional Hg-0 oxidation to HgCl2. (C) 2008 American Institute of Physics.