Research and engineering practice of catalytic absorption of NO2 by tetrabutylammonium hydrogen sulfate for simultaneous removal of SO2/NOx

Abstract

Under the pre-oxidation condition, NO can be removed simultaneously with SO2 in the existing wet desulfurization system. NO2 absorption efficiency in the wet desulfurization system is low, and additives need to be added to achieve efficient removal. In this work, a novel additive was used (tetrabutylammonium hydrogen sulfate, THS) for the simultaneous removal of NO2 and SO2. Both lab-scale and pilot-scale experimental systems were employed to study the absorption and removal characteristics of SO2 and NO2, and realize engineering application on a 35 t/h industrial boiler. It has been shown that the NO2 removal efficiency in a traditional wet desulfurization system is less than 20%. Adding THS can stabilize SO32− and improve the NO2 removal efficiency. SO2 can promote the absorption of NO2, but O2 in the flue gas and NO2– in the absorption system can inhibit the removal of NO2. In engineering, THS can increase the NO2 absorption efficiency from 13% to 70%, which has great application potential.