Simultaneous Estimation of Gas Adsorption Equilibria and Kinetics of Individual Shaped Adsorbents

Shaped adsorbents are typically employed in several gas separation and sensing applications. The performance of these adsorbents is dictated by two key factors, their adsorption equilibrium capacity and kinetics. Often, adsorption equilibrium and textural properties are reported for materials. Adsorption kinetics, despite its impact on performance in a given application, are seldom presented due to the challenges associated with measuring them. Therefore, robust and practical experimental approaches -- preferably using small quantities of material -- to characterize both the adsorption equilibrium and kinetics for shaped adsorbents is necessary. The overarching goal of this work is to develop an approach to characterize the adsorption properties of shaped adsorbents with less than 100 mg of sample. To this aim, we have developed an experimental dynamic sorption setup, complemented with mathematical models, to describe the mass transport in the system. We embed these models into a derivative-free optimizer to predict model parameters for adsorption equilibrium and kinetics. We evaluate the performance of our approach using three adsorbents. Further, we test the robustness of our mathematical framework using a digital twin. We show that framework can rapidly and quantitatively characterize adsorption properties at a milligram scale, making it suited for screening of novel porous materials.