Gas-phase elemental mercury removal by novel carbon-based sorbents

To develop cost-effective carbon-based sorbents used in gas-phase elemental mercury removal, the performance of commercial bamboo charcoal (BC) produced from renewable bioresource of bamboo and modified BC was investigated with a bench-scale fixed-bed reactor. The simple impregnation method was used to modify the BC using ZnCl2, NH3·H2O and HNO3 separately. BET, XPS, elemental analysis and FT-IR were used to determine the pore structure and surface chemistry of the sorbents. The characterization of the physical and chemical properties of sorbents in relation to Hg0 adsorption capacity provided important information on the Hg0 adsorption mechanism. This suggested that the modified BCs have excellent adsorption potential for elemental mercury at a relatively higher temperature of 140 °C except for the NH3·H2O impregnated BC. The amount of Hg0 absorbed depends on the concentration of impregnant used. The impregnation has increased the sorbents’ active sites for mercury adsorption and the specific reaction mechanism has been further analyzed.