A review on enhancing sulfur-resistant capacity and magnetism of adsorbent for mercury removal from coal fired flue gas

The injection of Hg adsorbent is commonly received as the most effective method for Hg removal in coal-fired flue gas. Both of SO 2 -poisoning resistance and magnetism are of great significance for Hg adsorbent to achieve the catalytic oxidation of Hg 0 and the separation with fly ash. In this study, the effects of environmental temperature and flue gas composition including O 2, NO, HCl, and H 2 O(g) on SO 2 resistance of Hg adsorbent were previously summarized. Then, the principle of four main methods for enhancing the SO 2 -poisoning resistance including active site protection method, active site increase method, oxygen active site avoidance method, and noble metal catalysis method were respectively introduced. Subsequently, the research status of magnetic adsorbent including magnetic carbon-based, magnetic zeolite-based, magnetic biochar, magnetic spinel-based, magnetosphere, and magnetic core–shell adsorbent were separately summarized. Subsequently, the environmental impact, economic feasibility, and industrial application prospects of current methods for enhancing SO 2 resistance and magnetism of Hg adsorbent were discussed. Based on these above, targeted suggestions and prospects including developing CuO-based catalytic adsorbent with good synergistic performance on SO 2 poisoning resistance and NO/Hg removal, maximizing the catalytic performance of SCR catalyst on Hg removal, developing low temperature SCR catalysts, developing magnetic core–shell structure with cooperative performance on SO 2 poisoning resistance and magnetic separation were respectively proposed.