Study on Simultaneous Removal of NOx and SO2 with NaClO2 in a Novel Swirl Wet System

This work attempts to utilize sodium chlorite to clean up NOx and SO2 gases simultaneously from flue gas in a novel swirl scrubber system. Experiments were carried out to evaluate the effects of various operating parameters such as initial SO2 concentration, scrubbing medium pH, sodium chlorite concentration, and liquid and gas volumetric flow rates at 35 degrees C. In addition, reaction mechanisms of simultaneous denitrification and desulfurization using sodium chlorite in acidic and basic solutions are proposed. Complete oxidation of NO into NO2 occurred using 0.2 M sodium chlorite solution as the scrubbing medium. Complete (100%) SO2 and 81% NOx removal efficiencies were achieved under optimized conditions. The NOx removal increased with decreasing pH. Input SO2 enhanced the NOx absorption. The effect of the SO2 concentration on NOx removal was more intense at higher pH values. Using sodium chlorite as the scrubbing medium in the novel swirl scrubber was found to be quite promising for the simultaneous removal of NOx and SO2.