Storage and Separation of CO2 and CH4 in Silicalite, C168 Schwarzite, and IRMOF-1: A Comparative Study from Monte Carlo Simulation

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• 作者：Ravichandar Babarao ; Zhongqiao Hu ; Jianwen Jiang ; Shaji Chempath ; Stanley I. Sandler
• 刊名：Langmuir
• 出版年：2007
• 出版时间：January 16, 2007
• 年：2007
• 卷：23
• 期：2
• 页码：659 - 666
• 全文大小：700K
• 年卷期：v.23,no.2(January 16, 2007)
• ISSN：1520-5827

文摘

Storage of pure CO₂ and CH₄ and separation of their binary mixture in three different classes of nanostructuredadsorbents-silicalite, C₁₆₈ schwarzite, and IRMOF-1-have been compared at room temperature using atomisticsimulation. CH₄ is represented as a spherical Lennard-Jones molecule, and CO₂ is represented as a rigid linear moleculewith a quadrupole moment. For pure component adsorption, CO₂ is preferentially adsorbed than CH₄ in all the threeadsorbents over the pressure range under this study, except in C₁₆₈ schwarzite at high pressures. The simulatedadsorption isotherms and isosteric heats match closely with available experimental data. A dual-site Langmuir-Freundlich equation is used to fit the isotherms satisfactorily. Compared to silicalite and C₁₆₈ schwarzite, the gravimetricadsorption capacity of pure CH₄ and CO₂ separately in IRMOF-1 is substantially larger. This implies that IRMOF-1might be a potential storage medium for CH₄ and CO₂. For adsorption from an equimolar binary mixture, CO₂ ispreferentially adsorbed in all three adsorbents. Predictions of mixture adsorption with the ideal-adsorbed solutiontheory on the basis of only pure component adsorption agree well with simulation results. Though IRMOF-1 has asignificantly higher adsorption capacity than silicalite and C₁₆₈ schwarzite, the adsorption selectivity of CO₂ over CH₄is found to be similar in all three adsorbents.