Hollow tubular MnOx prepared by flame annealing with cotton fiber as sacrificial template and its applications for Hg0 adsorption in flue gas

The mass discharge of mercury from coal-fired power plant has caused great harm, abating mercury emissions is of preoccupation for protecting public environmental safety and human health. Metal oxides are often used for Hg 0 removal in the flue gas. In this paper, a hollow tubular MnO x (MnCot) was successfully prepared by rapid flame annealing using cotton fiber as a sacrificial template. The MnCot were then well characterized and tested for its capability for Hg 0 removal in flue gas. The results indicate that the flame assisted synthesis method for rapidly prototyping metal oxides with typical structures is achievable. The hollow tubular structure of the cotton fiber is well reprinted with good crystallization of Mn 3 O 4 . The inner diameter of the hollow tubular MnCot is about 10 μm, and the thickness of the tube is about 1 μm. The Hg 0 removal efficiency on MnCot can be maintained as high as 90 % under simulated flue gas atmosphere below 240°C. O 2 and NO have a positive effect on the Hg 0 removal, which can act as the fresh active sits thus enhancing its capability for Hg 0 removal. However, the presence of SO 2 will result in the surface sulfation on MnCot, thus deteriorating its capability for Hg 0 removal. Further, the competitive adsorption between SO 2 and Hg 0 on the material will also weaken its capability for Hg 0 removal. The hollow tubular MnO x rapidly prepared by one-step flame annealing has a good industrial application potential for Hg 0 removal in coal-fired flue gas.