Efficient removal of Hg0 by the combination of CuO and excellent carrier Ta2O5

Abstract

A carrier Ta2O5 was introduced and combined with CuO for the removal of Hg0 in flue gas This combination exhibited an excellent performance and demonstrated robust resistance to both water and SO2 when compared to commonly used carriers (TiO2, Al2O3, etc.). CuO0.35/Ta2O5 manifested the highest Hg0 removal efficiency and excellent stability among all synthesized samples, reaching nearly 95 % in the initial stage. The introduction of O2 can improve the removal rate of Hg0, and the present of SO2 did not lead to catalyst poisoning. Physicochemical characterization revealed that CuO0.35/Ta2O5 possessed a high specific surface area and good thermal stability. Besides, copper was evenly distributed on the catalyst surface, and the combination of CuO and Ta2O5 enhanced the oxidation property of the catalyst. The removal mechanism of Hg0 was investigated and it was found that Hg0 binded to lattice oxygen on the catalyst after oxidation. A portion of the bound mercury was adsorbed on the catalyst, while the remainder was released into the flue gas.