Martín-Calvo Ana, García-Pérez Elena, Manuel Castillo Juan, Calero Sofia
Department of Physical, Chemical, and Natural Systems, University Pablo de Olavide, Ctra. Utrera km. 1., 41013 Seville, Spain.
Phys Chem Chem Phys. 2008 Dec 21;10(47):7085-91. doi: 10.1039/b807470d. Epub 2008 Oct 16.
We use Monte Carlo simulations to study the adsorption and separation of the natural gas components in IRMOF-1 and Cu-BTC metal-organic frameworks. We computed the adsorption isotherms of pure components, binary, and five-component mixtures analyzing the siting of the molecules in the structure for the different loadings. The bulk compositions studied for the mixtures were 50 : 50 and 90 : 10 for CH4-CO2, 90 : 10 for N2-CO2, and 95 : 2.0 : 1.5 : 1.0 : 0.5 for the CH4-C2H6-N2-CO2-C3H8 mixture. We choose this composition because it is similar to an average sample of natural gas. Our simulations show that CO2 is preferentially adsorbed over propane, ethane, methane and N2 in the complete pressure range under study. Longer alkanes are favored over shorter alkanes and the lowest adsorption corresponds to N2. Though IRMOF-1 has a significantly higher adsorption capacity than Cu-BTC, the adsorption selectivity of CO2 over CH4 and N2 is found to be higher in the latter, proving that the separation efficiency is largely affected by the shape, the atomic composition and the type of linkers of the structure.
我们使用蒙特卡罗模拟来研究天然气成分在IRMOF-1和Cu-BTC金属有机框架中的吸附和分离。我们通过分析不同负载量下分子在结构中的位置，计算了纯组分、二元混合物和五元混合物的吸附等温线。研究的混合物的总体组成中，CH4-CO2为50:50和90:10，N2-CO2为90:10，CH4-C2H6-N2-CO2-C3H8混合物为95:2.0:1.5:1.0:0.5。我们选择这种组成是因为它类似于天然气的平均样本。我们的模拟表明，在整个研究压力范围内，CO2比丙烷、乙烷、甲烷和N2更优先被吸附。较长链烷烃比较短链烷烃更受青睐，吸附量最低的是N2。尽管IRMOF-1的吸附容量明显高于Cu-BTC，但发现后者对CO2相对于CH4和N2的吸附选择性更高，这证明分离效率在很大程度上受结构的形状、原子组成和连接体类型的影响。
