Adsorption of gas mixtures in micropores: effect of difference in size of adsorbate molecules

✍ Scribed by Jude Dunne; Alan L. Myers

• Book ID: 103011180
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 913 KB
• Volume: 49
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(94)e0112-4

✦ Synopsis

Adsorbed solutions of molecules of unequal size (CC1 2F2 and CO 2 on activated carbon) show negative deviations from ideal mixing . The size effect was studied by molecular simulation of a Lennard-Jones fluid mixture adsorbed in zeolite 13X . The molecules forming the binary mixture are non-polar and have a 2 .4 ratio of saturation capacities (the same as CC1 2 F2 and C0 2). In the molecular simulation, adsorption occurs on the energetically homogeneous surface of a spherical shell . Binary adsorption is centered on separate shells with the larger molecule in the inner shell . At high coverage, the simulations yield moderate negative deviations from ideal mixing similar to experimental data . Both molecules can enter the cavity, but adsorbed-phase nonidealities are caused by the exclusion of the larger molecule from part of the micropore space accessible to the smaller molecule . The partial exclusion effect is calculated from the cavity radius and molecular diameters of the adsorbate molecules .