Simultaneous Removal of NOx and SO2 by MgO Combined with O3 Oxidation: The Influencing Factors and O3 Consumption Distributions

Simultaneous removal of NOx and SO2 by MgO combined with O3 oxidation was studied. The effects of the O3/NO molar ratio, oxidation temperature, and oxidation residence time on N2O5 decomposition and O3 consumption distributions were systematically illustrated, which is of great significance for improving NOx removal efficiency and reducing O3 consumption in practical application. When the O3/NO molar ratio was greater than 1.0, the highest N2O5 yield was achieved at 90 °C. The NOx removal efficiency reached 96.5% at an O3/NO molar ratio of 1.8. The oxidation temperature increased from 90 to 130 °C, resulting in the decrease of N2O5 yield, the improvement of O3-ICC (O3 invalid cycle consumption) caused by N2O5 decomposition, and the decrease of NOx removal efficiency from 96.5 to 76%. Besides, the effects of pH, SO2 concentration, and MgSO3 addition on NOx removal efficiency were also investigated. The results showed that the removal efficiency of NOx decreased with the increase of SO2 concentration, while...