Abstract：The adsorption performance of modified lignite semi-coke with HCl or HNO3solution for gaseous Hg0was investigated to develop more effective and lower price adsorbents for reducing emission of elemental mercury in coal combustion flue. The surface properties of these lignite semi-coke adsorbents were characterized with methods of acid-base titration, Boehm titration, Brunauer-Emmett-Teller (BET) measurement, scanning electron microscope (SEM) and Fourier Transform infrared spectroscopy (FTIR), respectively. The adsorption experiments of semi-coke adsorbents for gas-phase Hg0have been carried out with a laboratory-scale fixed-bed reactor, and elemental mercury analyzer was used to determine the on-line concentrations of gas-phase Hg0. Nitric acid or hydrochloric acid treatment of lignite semi-coke resulted in the decrease in ash content of semi-coke sample, and the values of specific surface area, surface oxygen and phenolic hydroxyl group increasing of modified semi-cokes. Compared to raw lignite semi-coke (NM-SC), the modified lignite semi-coke with HCl or HNO3 solution (Cl-SC or N-SC sample) could improve removal performance for gas-phase Hg0. Especially, the removal performance for gas-phase Hg0of Cl-SC semi-coke was obviously improved when adsorption temperature increased to 140℃. These results were related to the surface properties of modified semi-coke and its contents of carboxyl group, phenolic hydroxyl and C-Cl functional groups, which can provide active sites for gaseous Hg0chemical adsorption.
王力, 刘秀丽, 张林林, 李敏, 张华伟. 酸改性对褐煤半焦脱除烟气中元素态汞性能的影响[J]. 中国环境科学, 2014, 34(12): 3056-3061.
WANG Li, LIU Xiu-Li, ZHANG Lin-Lin, LI Min, ZHANG Hua-Wei. Effect of lignite semi-coke by acid solution treatment on its performance for elemental mercury removal in the flue gas. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(12): 3056-3061.
