Simultaneous removal of SO2 and NO by a vaporized enhanced-Fenton reagent

•An enhanced-Fenton reagent proved to be effective for removing SO2 and NO from flue gas.•A pre-oxidation process based on a vaporized complex oxidant was proposed for flue gas cleaning.•The reaction mechanism of simultaneous removal of SO2 and NO was speculated.

A novel integrative process for simultaneously removing SO2 and NO from coal-fired flue gas was designed, in which, SO2 and NO, especially NO, were initially oxidized by a vaporized enhanced-Fenton reagent (EF) made up of hydrogen peroxide, peroxyacetic acid, and ferrous sulfate, and then absorbed by Ca(OH)2 that followed. The experimental results indicated that the removal of NO was significantly affected by the adding rate of EF solution, the flue gas residence time, and the pH of EF solution, and slightly affected by the reaction temperature and the concentration of SO2. Under the optimal reaction conditions, the simultaneous removal efficiencies of 100% for SO2 and 89.2% for NO were obtained. Meanwhile, the reaction mechanism of simultaneous removal of SO2 and NO was speculated based on the related literature references and the characterizations of removal product by scanning electron microscope, energy dispersive X-ray spectrometer, and X-ray diffraction.