SPRAY SCRUBBING OF THE NITROGEN OXIDES INTO NaClO₂ SOLUTION UNDER ACIDIC CONDITIONS

Abstract

The operating conditions of this study were closed to the typical operating conditions of flue gas desulfurization system in the coal-fired power plant. The objective of this study was to investigate the absorption performance of lean NO in an aqueous solution of acidic sodium chlorite using a bench-scale spraying column. The NO conversion and NO_X removal efficiency were increasing with the increasing NO concentration, retention time, sodium chlorite concentration, operating temperature, and decreasing initial pH of solution. As the sodium chlorite concentration were higher than 0.4 M, the NO conversion and NO_X removal efficiency were 100% and 80%, respectively. The NO conversion and NO_X removal efficiency under initial pH 4–7 were higher than that of initial pH >7. It meant that this process might be suitable to combining with traditional wet flue gas desulfurization system. As the NO₂/NO_X ratio in the effluent gas was closed to 0.5, it might be suitable to be absorbed in the second scrubbing column operated under alkaline condition.

Keywords:

• Sodium chlorite
• Spray scrubbing
• Nitrogen oxides
• Flue gas treatment

ACKNOWLEDGMENTS

This study was funded by National Science Council, Republic of China (Contract No. NSC 83-0410-E-006-075).