Effect of Surface Chemistry and Textural Properties of Activated Carbons for CH4 Selective Adsorption through Low-Concentration Coal Bed Methane

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• 作者：Hongyan Pan ; Yun Yi ; Qian Lin ; Guangyan Xiang ; Yu Zhang ; Fei Liu
• 刊名：Journal of Chemical & Engineering Data
• 出版年：2016
• 出版时间：June 9, 2016
• 年：2016
• 卷：61
• 期：6
• 页码：2120-2127
• 全文大小：433K
• 年卷期：0
• ISSN：1520-5134

文摘

A series of activated carbon were prepared, modified, and characterized by FTIR, Boehm titration, and N₂ adsorption/desorption isotherms. Adsorption breakthrough experiments of CH₄ through low-concentration coal bed methane (CBM) were carried out for measuring adsorption capacities (Q_m) of adsorbents toward CH₄ at 293 K. Adsorption isotherms of CH₄, N₂, and O₂ were measured between 25 mm Hg and 760 mm Hg at 293 K and fitted by Langmuir model to calculate separation coefficient of CH₄ against N₂ and O₂ (α_CH4/N2 and α_CH4/O2). Results show that CH₄ adsorption occurs mainly at the micropore of activate carbon, and the surface basic group of activate carbon can strengthen its adsorption ability toward CH₄. Adsorption capacities of CH₄ on modified AC are higher than that on original AC. The adsorbent KCl/AC has the largest micropore volume and more amount of basic group and this makes it the largest uptake of CH₄ (7.89 mL/g) at 293 K and 1 atm; it is 38.9% higher than that of original AC (5.68 mL/g). Separation coefficient of α_CH4/N2 on KCl/AC is 5.33, compared to 3.85 for AC; it is 38.4% higher than that of the original AC.