Efficient removal of Hg0 by regulating the bonding degree between CuO and carrier Nb2O5

Abstract

Nb2O5 is introduced to act as a novel carrier of CuO using for Hg0 removal, presenting the excellent performance compared to niobium combined with other metal oxides (MnO2, CeO2, Fe2O3). By regulating the calcination temperature and CuO load amount, it was found that the formative stage of CuNb2O6 was the optimum binding degree of CuO and Nb2O5, which was beneficial for strong interaction of active component and carrier. Hg0 removal behaviors showed Cu0.5/Nb2O5 exhibited the high Hg0 adsorption capacity, about 0.32 mg/g for 200 min at 150 ℃, and had a wide temperature range (100–250 ℃). SO2 and H2O have slight toxic effects on Hg0 capture, while O2 plays an important role in Hg0 capture. Studies on the structure and properties of samples manifested CuO was homogeneously dispersed on the surface of Nb2O5, and Cu0.5/Nb2O5 had good thermal stability and abundant surface acid property, besides, Cu+ specie can be more easily generated, which was beneficial for Hg0 removal in the flue gas. Furthermore, the removal mechanism of Hg0 was also studied, manifested Cu0.5/Nb2O5 can be considered as a promising mercury adsorbent for various applications.