Study Of Elemental Mercury Removal From Flue Gases By Modified Mineral Sorbents

Mercury has become a hotspot research in recent years for the high-volatility、hypertoxicity、Bio accumulate. China is one of the main countries for the high mercuryemissions in the world, and power plants are the main source of anthropogenic mercury. Sothe control of mercury in power plants becomes imperative. The existing pollution controlsystem can control bivalent mercury and particulate mercury in power plant, while thecontrol of elemental mercury mainly depends on sorbent injection. Activated carbon is themost widely used adsorbent currently. However, it is limited by some reasons in actual use.The natural mineral adsorbent has become the hot spot in research due to its lowcost andextensive sources.Two type of natural minerals, bentonite(Ben) and attapulgite(Atp),were selected as rawsorbents. CuCl2、CuBr2、NaBr、S、MnO2、Co3O4were selected as modifiers for bentoniteand attapulgite, which were prepared by impregnation. CuCl2、CuBr2can promote theefficiency to about90%，while NaBr and sulfur can promote the efficiency to about80%.Metal oxide modifiers can improve the efficiency to about88%.We also studied the effect of O2、HCl、SO2、NO on Hg0removal.The results showedthat O2can promote the Hg0removal efficiency especially for metal oxide modifiers.4%ofO2can promote the Hg0removal efficiency by about5%. As to the halogen elementmodified adsorbents, HCl has no significant effect on Hg0removal. SO2has greatprohibitive effect on Hg0removal especially for metal oxide modification.400ppmSO2mayprohibit the Hg0removal efficiency by about20%.