(276c) On the Use of a New Kinetic Model in a Cyclic Adsorption Process Simulator for Kinetically Limited Gas Separations

Current kinetics models, typically LDF models, have been applied on the basis that the presence of a second, slower diffusing, adsorbate affects the equilibrium of the first, faster diffusing, adsorbate in a gas mixture via its gas phase partial pressure. However, this premise is contrary to experimental observations involving either butane or ethane with CO₂ on carbon molecular sieves. The objective of the work is two-fold. First, a new non-equilibrium model that augments the equilibrium driving force in the LDF kinetic model, such that the equilibrium loading of one component depends on the actual loading of the other component in a gas mixture will be presented. Further, in this new model, the equilibrium loading of one component depends on the actual loading of the other component, with both leading to the extended Langmuir model predictions at equilibrium. Second, it will be shown how this new kinetic model performs within the framework of the UofSC dynamic adsorption process simulator (DAPS). Two key kinetically limited binary gas separations with a carbon molecular sieve (CMS) are being examined both experimental and with DAPS using different PSA cycle schedules. These are CO₂-CH₄ and CO₂ N₂ gas mixtures. The latest results will be presented.