Simultaneous Removal of SO2 and NO Using H2O2/Urea Activated by Vacuum Ultraviolet Light in a Pilot-Scale Spraying Tower

Abstract

A study on simultaneous removal of SO2 and NO from flue gas using H2O2/urea activated by vacuum ultraviolet (VUV) light was carried out in a pilot-scale photochemical spraying tower. The effects of different operational variables on simultaneous removal efficiencies of SO2 and NO were investigated. The gaseous and liquid removal products were detected by the flue gas analyzer and ion chromatography (IC), respectively. The removal pathways of SO2 and NO were analyzed. The application prospect of this new method was also preliminarily discussed. Results show that under most of the process conditions tested, SO2 can attain complete removal. Removal efficiency of NO is enhanced under increasing the VUV irradiation intensity and H2O2 concentration, but it is inhibited by an increase of the flue gas flow and NO concentration. The urea concentration and liquid–gas ratio have a dual influence on NO removal, and its removal efficiency increases first and then decreases. SO2 concentration has little impact on NO re...