Study on the removal of elemental mercury from simulated flue gas by Fe2O3-CeO2/AC at low temperature

摘要

Fe2O3 and CeO2 modified activated coke (AC) synthesized by the equivalent-volume impregnation were employed to remove elemental mercury (Hg-0) from simulated flue gas at a low temperature. Effects of the mass ratio of Fe2O3 and CeO2, reaction temperature, and individual flue gas components including O-2, NO, SO2, and H2O (g) on Hg-0 removal efficiency of impregnated AC were investigated. The samples were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Results showed that with optimal mass percentage of 3 % Fe2O3 and 3 % CeO2 on Fe3Ce3/AC, the Hg-0 removal efficiency could reach an average of 88.29 % at 110 A degrees C. Besides, it was observed that O-2 and NO exhibited a promotional effect on Hg-0 removal, H2O (g) exerted a suppressive effect, and SO2 showed an insignificant inhibition without O-2 to some extent. The analysis of XPS indicated that the main species of mercury on used Fe3Ce3/AC was HgO, which implied that adsorption and catalytic oxidation were both included in Hg-0 removal. Furthermore, the lattice oxygen, chemisorbed oxygen, and/or weakly bonded oxygen species made a contribution to Hg-0 oxidation.