Influence of modified lignite activated coke on mercury removal from simulated flue gas

WU Peng; TENG Jilin; ZHANG Xuhui; ZHAO Yueju

doi:10.13226/j.issn.1006-6772.2015.02.009

Abstract：In order to reduce mercury removal cost from flue gas and improve mercury removal performance of activated coke,the Xilinhot lignite was chosen to prepare activated coke which was further modified by a series of chemical methods. The influence of sulfur,Na2 S, ZnCl2 impregnating on the structure and properties of activated coke was studied. Further more,the effects of modified methods,adsorbent temperature,capacity and mercury infiltration capacity on activated coke mercury removal performance were researched. The results showed that,after modification,the specific surface area and pore volume of activated coke decreased. Compared to the original activated coke,mer-cury adsorption of AC-Na2 S,AC-S and AC-ZnCl2 was respectively increased by 60%,113% and 140%. With the proportion of modifier to activated coke increased,the mercury adsorption capacity increased. With the adsorption temperature increased,the chemical reaction became faster,the initial efficiency of mercury removal could be increased from 75. 8% to above 95%,while the penetrate time didn’t in-crease proportional. When the ZnCl2 content in activated coke increased from 5% to 15%,the time which was needed to achieve 50% pen-etration rate increased from 75 minutes to 120 minutes,the mercury adsorption capacity of AC-ZnCl2 increasedfrom 10. 1 μg/g to 17. 5μg/g. With the increase of mercury infiltration capacity,the mercury removal efficiency increased,the time which was needed to achieve 50% penetration rate decreased from 110 minutes to 95 minutes. Finally ,the total adsorption increased from 14. 4 μg/g to 16. 2 μg/g.