Efficient removal of mercury from flue gases by regenerable cerium-doped functional activated carbon derived from resin made by in situ ion exchange method

Cerium-doped activated carbon with high dispersions of cerium and sulfur species was successfully synthesized by an in situ ion exchange method. A high space velocity was employed to differentiate the mercury removal performance of cerium-doped activated carbon with (Ce/AC) and without (Ce/C) activation in simulated flue gases , at 80 to 150 °C. The Ce/AC showed much higher mercury removal ability than those of Ce/C, commercial coconut AC and NH 4 Cl modified AC. The main mercury species formed over spent Ce/AC were HgO, HgS and HgSO 4 . The HgO was formed mainly through the oxidation of mercury by lattice oxygen, while the HgS was generated by the reaction between Ce 2 S 3 and mercury. The formation of HgSO 4 might be due to the reaction of mercury with SO 2 and/or Ce 2 S 3 with the aid of oxygen. The Ce/AC showed impressive regeneration and reuse ability, the mercury removal performance of which showed no obvious change even after 5 runs of regeneration. The mercury species formed over Ce/AC also had no obvious change after regeneration; however, the Ce 2 S 3 over Ce/AC was converted to CeO 2 after regeneration. With the above excellent properties, Ce/AC may prove to be an advantageous alternative to commercial AC for mercury removal in power plants.