Three-dimensional ordered zeolite-templated carbon with covalent sulfur for efficient removal of elemental mercury: Experimental study and molecular dynamic simulation

Abstract

Traditional activated carbon used to remove elemental mercury (Hg0) from coal-fired power plants exhibit an irregular porous structure, showing an adverse effect on the removal of Hg0. To obtain carbon materials with a regular porous structure, zeolite-templated carbon samples (ZTC and S-doped ZTC) with a three-dimensional ordered structure were synthesized via the chemical vapor deposition (CVD) method using C2H2 and H2S as the carbon and sulfur precursor on BEA zeolite. Several techniques including TG-MS, SEM-TEM-EDS, etc. were used to determine that ZTC replicated the regular microporous structure of zeolite and generated turbostratic carbon. Moreover, the Hg0 removal efficiency (MRE) of ZTC samples was investigated. At 30 °C, they removed Hg0 mainly by physisorption, while at 150 °C, chemisorption was the dominant approach for capturing Hg0. The influence of flue gas components (H2O, NH3, and SO2) on the MRE of ZTC-HS was further studied by experimental methods and molecular dynamic (MD). H2O and NH3 weakened the MRE of ZTC-HS due to the competing adsorption. The effect of SO2 on the MRE of ZTC-HS was related to its concentration. Because of its advantages in regeneration features, preparation cost and higher resistance to flue gas components, ZTC-HS exhibited the potential for industrial applications.