Removal of Gaseous Elemental Mercury by Cylindrical Activated Coke Loaded with CoOx-CeO2 from Simulated Coal Combustion Flue Gas

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• 作者：Huiyu Wu ; Caiting Li ; Lingkui Zhao ; Jie Zhang ; Guangming Zeng ; Yin鈥檈 Xie ; Xunan Zhang ; Yan Wang
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：October 15, 2015
• 年：2015
• 卷：29
• 期：10
• 页码：6747-6757
• 全文大小：765K
• ISSN：1520-5029

文摘

Co鈥揅e mixed oxides were loaded on commercial cylindrical activated coke granules (CoCe/AC) by an impregnation method to remove gaseous elemental mercury (Hg⁰) from simulated coal combustion flue gas at low temperature (110鈥?30 掳C). Effects of the Co/Ce molar ratio in Co鈥揅e mixed oxides, mixed oxides loading value, reaction temperature, and flue gas components (O₂, NO, SO₂, H₂O) on Hg⁰ removal efficiency were investigated, respectively. Brunauer鈥揈mmett鈥揟eller analysis, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) analysis were employed to analyze the characteristics of the samples. Results showed that up to 92.5% of Hg⁰ removal efficiency could be obtained over Co_4.5Ce₆/AC at 170 掳C. The remarkably high Hg⁰ removal ability of Co_4.5Ce₆/AC mainly depended on the synergetic effect between cobalt oxide and ceria. Additionally, different with the pure N₂ condition, the existence of O₂ and NO could increase Hg⁰ removal efficiency. SO₂ exhibited an inhibitive effect on Hg⁰ removal in the absence of O₂. H₂O(g) could slightly hinder Hg⁰ removal. The characterization results exhibited that addition of cobalt oxide led to the excellent dispersity of CeO₂ on AC. TGA and XPS analysis results revealed that the captured mercury species on the used Co_4.5Ce₆/AC mainly existed as HgO, and both lattice oxygen and chemisorption oxygen contributed to Hg⁰ oxidation. Furthermore, the mechanisms involved in Hg⁰ removal were identified.