Novel method for high-performance simultaneous removal of NO and SO2 by coupling yellow phosphorus emulsion with red mud

This study develops a novel method for simultaneously removing NOx and SO2 from coal-fired flue gas via coupling yellow phosphorus emulsion with red mud. The effects of different factors on the synergistic purification of sulphur-nitric acid were investigated in this study. The achieved removal efficiencies of NOx and SO2 were as high as 97.9% and 100%, respectively, under optimized conditions. This indicates that the yellow phosphorus emulsion coupled with red mud as a composite absorbent is favorable for simultaneous removal effect on NOx and SO2. The samples before and after the reaction were characterized using X-ray diffraction, X-ray fluorescence, inductively coupled plasma, scanning electron microscopy, and other methods, and the main product was identified as gypsum (CaSO4·2H2O) after desulfurization and denitrification. Adsorption kinetics, isotherm adsorption, and breakthrough curve models of NOx and SO2 adsorption on red mud were established. Moreover, the mechanism of multiphase oxidation and absorption reactions for simultaneous desulfurization and denitrification was also speculated.