Sketching a Portrait of the Optimal Adsorbent for CO2 Separation by Pressure Swing Adsorption

Abstract

In silico screening of CO2 adsorbents is a very powerful method for preselecting the most promising porous solids for experimental studies. Because of increased computational power, it is now possible to investigate a large number of adsorbents in a fairly short time. However, it remains difficult to rationalize structure–performance correlations because the complexity of such porous materials cannot be reduced to a few simple descriptors. In this paper, we present a different approach that was applied to the design of an optimal adsorbent for CO2 separation from gas mixtures. A CO2–CH4 mixture was used as the feed. We constructed a simplified model of the porous material by adopting a spherical pore geometry. From the dispersion–repulsion point of view, the spherical pore was modeled by homogeneously distributed Lennard-Jones sites. Besides, a charge distribution was introduced to mimic the electrostatic behavior. The selected charge distribution is constituted of negative charges homogeneously distribut...