Gas-phase elemental mercury capture by a V2O5/AC catalyst

Gas-phase elemental mercury (Hg0) capture by an activated coke (AC) supported V2O5 (V2O5/AC) catalyst was studied in simulated flue gas and compared with that by the AC. The study on the influences of V2O5 loading, temperature, capture time and flue gas components (O2, SO2, H2O and N2) shows that the Hg0 capture capability of V2O5/AC is much higher than that of AC. It increases with an increase in V2O5 loading and is promoted by O2, which indicates the important role of V2O5 in Hg0 oxidation and capture; it is promoted slightly by SO2 but inhibited by H2O; it increases with an increase in temperature up to 150 °C when Hg desorption starts. X-ray photoelectron spectroscopy analysis and sequential chemical extraction experiments indicate that the main states of Hg captured on V2O5/AC are HgO and HgSO4. Temperature programmed desorption experiments were also made to understand the stability of the Hg captured.