Influence of flue gas components on the mercury adsorption/oxidation by mechanochemical S2Cl2-modified sawdust coke

The effects of flue gas components (O2, CO2, SO2 and NO) on the Hg0 removal of mechanochemical S2Cl2-modified BC (S2Cl2-MC) were explored based on the Hg0 removal efficiency/amount, Hg0 adsorption amount and Hg2+ escape amount/ratio. The BET, FTIR, XPS, and Hg-TPD were used to obtain relevant physicochemical properties. It shows O2 and CO2 promote the Hg2+ escape but inhibit Hg0 adsorption. O2 slightly affects Hg0 removal, while CO2 promotes it. 400 ∼ 800 ppm SO2 slightly affect Hg0 removal, while 1200 ppm SO2 facilitates Hg2+ escape and Hg0 adsorption. SO2 affects Hg2+ escape ratio little. As NO concentration increases, the Hg2+ escape is promoted while Hg0 adsorption is inhibited. O2 and CO2 do not change the mercury forms. SO2 and NO promote the production of HgSO4 and Hg(NO3)2, respectively. The Hg0 adsorption might mainly depend on the physical properties of adsorbents.