Promotional removal of gas-phase Hg0 over activated coke modified by CuCl2

Zhang, Jie; Li, Caiting; Du, Xueyu; Gao, Lei; Li, Shanhong; Zhang, Yindi; Li, Zhenyu; Yi, Yaoyao

Promotional removal of gas-phase Hg0 over activated coke modified by CuCl2

2020

Impregnating CuCl₂ on AC (activated coke) support to synthesize xCuCl₂/AC showed superior activity with higher 90% Hg⁰ removal efficiency at 80–140 °C, as well as a lower oxygen demand of 2% O₂ for Hg⁰ removal. The acceleration on Hg⁰ removal was observed for NO and SO₂. The BET, SEM, XRD, XPS, TPD, and FT-IR characterizations revealed that the larger surface area, sufficient active oxygen species and co-existence of Cu⁺ and Cu²⁺ may account for the efficient Hg⁰ removal. In addition, the low demand of gaseous O₂ was contributed to higher content of active oxygen and formed active Cl. After adsorbing on Cu sites, Cl sites, and surface functional groups, the Hg⁰₍ₐdₛ₎ removal on xCuCl₂/AC was proceeded through two ways. Part of Hg⁰₍ₐdₛ₎ was oxidized by active O and formed Hg⁰, and the other part of Hg⁰ combined with the active Cl, which was formed by the activation of lattice Cl with the aid of active O, and formed HgCl₂. Besides, the Hg²⁺ detected in outlet gas through mercury speciation conversion and desorption peak of HgCl₂ and Hg⁰ further proved it. As displayed in stability test and simulated industrial application test, CuCl₂/AC has a promising industrial application prospect.

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