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

摘要

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 Hg° adsorption capacity provided important information on the Hg~0 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 Hg~0 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.