Open Access

ARTICLE

An Experimental Study on Oxidized Mercury Adsorption by Bromide Blended Coal Combustion Fly Ash

by Mingyu Yu¹, Mengyuan Liu¹, Guangqian Luo^1,2,*, Ruize Sun¹, Jingyuan Hu¹, Hailu Zhu¹, Li Zhong³, Lipeng Han³, Xian Li¹, Hong Yao¹

1 State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
2 Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, 518000, China
3 Huaneng Clean Energy Technology Research Institute, Beijing, 102209, China

* Corresponding Author: Guangqian Luo. Email:

Energy Engineering 2021, 118(5), 1277-1286. https://doi.org/10.32604/EE.2021.014810

Received 01 November 2020; Accepted 11 March 2021; Issue published 16 July 2021

Abstract

The application of forced mercury oxidation technology would lead to an increase of Hg²⁺ concentration in the flue gas. Although Hg²⁺ can be easily removed in the WFGD, the mercury re-emission in the WFGD can decrease the total removal of mercury from coal-fired power plants. Hence, it is necessary to control Hg²⁺ concentration in the devices before the WFGD. Fly ash adsorbent is considered as a potential alternative for commercial activated carbon adsorbent. However, the adsorption efficiency of the original fly ash is low. Modification procedure is needed to enhance the adsorption performance. In this study, the adsorption of Hg²⁺ by brominated fly ash was studied. The fly ash was collected from the full-scale power plant utilizing bromide-blended coal combustion technology. The brominated fly ash exhibited excellent performance for Hg²⁺ removal. The flue gas component HBr and SO₂ could improve adsorbent’s performance, while HCl would hinder its adsorption process. Also, it was demonstrated by Hg-TPD experiments that the adsorbed Hg²⁺ mainly existed on the fly ash surface in the form of HgBr₂. In summary, the brominated fly ash has a broad application prospect for mercury control.

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