Hg0 Removal by V2O5 Modified Palygorskite in Simulated Flue Gas at Low Temperature

Abstract

The V2O5-modified palygorskite (V2O5/PG catalysts) were prepared and used for Hg0 removal in simulated flue gas at low temperature. It was found that the V2O5/PG catalyst had excellent performance for Hg0 removal at 150 °C. O2 exhibited a positive effect on Hg0 removal over V2O5/PG, while SO2 and H2O showed an inhibiting effect. However, Hg0 removal efficiency showed a promotion trend in the presence of H2O, SO2, and O2. The Brunauer–Emmett–Teller (BET) method, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were applied to characterize the physicochemical properties of the V2O5/PG catalyst. Mercury temperature-programmed desorption (Hg-TPD) experiments were also conducted to identify the mercury species adsorbed on the V2O5/PG catalyst, and the pathway of Hg0 removal over V2O5/PG was also discussed. The used V2O5/PG catalyst after Hg0 removal was regenerated, and its capability for Hg0 removal can be completely recovered. The V2O5/PG-Re-300 °C catalyst showed excellent performance and good stability for Hg0 removal after regeneration.