Study on the removal of NO x from simulated flue gas using acidic NaClO 2 solution

Abstract

The study on the removal of NO x from simulated flue gas has been carried out in a lab-scale bubbling reactor using acidic solutions of sodium chlorite. Experiments were performed at various pH values and inlet NO concentrations in the absence or presence of SO 2 gas at 45°C. The effect of SO 2 on NO oxidation and NO 2 absorption was critically examined. The oxidative ability of sodium chlorite was investigated at different pH values and it was found to be a better oxidant at a pH less than 4. In acidic medium, sodium chlorite decomposed into ClO 2 gas, which is believed to participate in NO oxidation as well as in NO 2 absorption. A plausible NO x removal mechanism using acidic sodium chlorite solution has been postulated. A maximum NO x removal efficiency of about 81% has been achieved.