Experimental Study on the Elemental Mercury Removal Performance and Regeneration Ability of CoOx–FeOx-Modified ZSM-5 Adsorbents
Wei Ma, Dong Ye, Haining Wang
Abstract
Herein, a series of Co-Fe mixed oxide modified ZSM-5 adsorbents were synthesized using the ultrasonic-assisted impregnation method for the capture of elemental mercury. In comparison with other samples, Co4Fe1-ZSM-5 produced a relatively better performance, with the removal efficiency of around 96.6% Hg0 and the adsorption capacity of around 901.63 ug/mg Hg0 achieved at 120 °C. The interaction between CoOx and FeOx improved the reducibility of oxygen species, thus promoting the oxidation of Hg0. Among a variety of other gas components, O2 and NO exerted a positive effect on Hg0, which improved its removal to a certain extent. By contrast, SO2 caused an adverse effect on the capture of Hg0, which could be reversed to some degree by the introduction of 5% O2. After five cycles, the mercury removal efficiency of Co4Fe1-ZSM-5 remained above 90%, suggesting excellent recyclability. Finally, XPS analysis was conducted to reveal that Mars–Maessen mechanisms are dominant in the process of mercury adsorption.