负载 Mn-Ni 氧化物的活性炭对燃煤烟气中元素汞的吸附和氧化。

Adsorption and oxidation of elemental mercury from coal-fired flue gas over activated coke loaded with Mn-Ni oxides.

机构信息

College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.

Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, People's Republic of China.

出版信息

Environ Sci Pollut Res Int. 2019 May;26(15):15420-15435. doi: 10.1007/s11356-019-04864-1. Epub 2019 Apr 2.

DOI:10.1007/s11356-019-04864-1

PMID:30941710

Abstract

A series of Mn-Ni/AC (AC, activated coke) catalysts were synthesized by the impregnation method for the removal of elemental mercury (Hg) from simulated flue gas. The samples were characterized by BET, ICP-OES, SEM, XRD, XPS, H-TPR, FT-IR, and TGA. MnNi/AC exhibited optimal removal efficiency of 96.6% in the condition of 6% O and balanced in N at 150 °C. The experimental results showed that both O and NO facilitated Hg removal. SO could restrain the Hg removal in the absence of O, while the inhibitory effect of SO was weakened with the aid of 6% O. In addition, HO exhibited a slightly negative influence on Hg removal. The characterization of the samples indicated that MnNi/AC possessed larger specific surface area, higher dispersion of metal oxides, and stronger redox ability. In the meantime, the results of XPS and FT-IR demonstrated that the lattice oxygen and chemisorbed oxygen made contributions to Hg removal and the consumed oxygen could be compensated by the redox cycle of metal oxides and gas-phase O. Meanwhile, the mechanisms of Hg removal were proposed based on the above studies.

摘要

采用浸渍法制备了一系列 Mn-Ni/AC（AC，活性炭）催化剂，用于脱除模拟烟气中的元素汞（Hg）。采用 BET、ICP-OES、SEM、XRD、XPS、H-TPR、FT-IR 和 TGA 对样品进行了表征。在 6%O 和平衡 N 条件下，150°C 时 MnNi/AC 的去除效率最佳，为 96.6%。实验结果表明，O 和 NO 均有利于 Hg 的去除。SO 在没有 O 的情况下会抑制 Hg 的去除，而在有 6%O 的情况下，SO 的抑制作用会减弱。此外，HO 对 Hg 的去除有轻微的负面影响。样品的表征表明，MnNi/AC 具有较大的比表面积、更高的金属氧化物分散度和更强的氧化还原能力。同时，XPS 和 FT-IR 的结果表明，晶格氧和化学吸附氧对 Hg 的去除有贡献，消耗的氧可以通过金属氧化物和气相 O 的氧化还原循环来补偿。同时，基于上述研究提出了 Hg 去除的机理。