Simultaneous Removal of SO 2 , NO X , and Hg from Coal Flue Gas Using a NaClO 2 -Enhanced Wet Scrubber

A bench-scale study was conducted on the simultaneous removal of SO 2, NO X, and mercury (both Hg 0 and Hg 2+ ) from a simulated coal flue gas using a wet calcium carbonate scrubber. The multipollutant capacity of the scrubber was enhanced with the addition of the oxidizing salt, sodium chlorite. The results showed a maximum scrubbing of 100% for SO 2 and Hg species and near complete NO oxidation with about 60% scrubbing of the resulting NO X species. The chlorite additive was less effective as an oxidant in the absence of SO 2 and NO in the flue gas. Oxidation of NO and mercury were only about 50% and 80%, respectively, in the case of no SO 2 in the simulated flue gas. The mercury oxidation was similarly affected by the absence of NO in the flue gas.