(281f) Do Performance Indicators Predict Adsorption Process Performance? the Case of Post-Combustion CO2 Capture

Finding the right adsorbent for adsorptive post-combustion carbon capture has been a research topic that has been actively pursued around the globe. Most studies in the literature have focused on materials development. Several new metal organic framework (MOF), zeolites and carbon-based materials have been reported. Based on equilibrium and kinetic parameters, researchers have argued the superiority of one material over the other. Various performance metrics have been proposed in the literature, e.g., various forms of selectivities, loading ratios, figures of merit etc. Firstly, many of the parameters were developed for light-product purification while separations such as CO2 capture deal with the purification of the heavy component. Secondly, it is not known which performance parameter(s), e.g., purity, recovery, productivity, energy consumption etc. do they correlate to. Very often when trying to rank materials, the various metrics identify a different material to be superior. 

We consider the case of CO2 capture from dry post-combustion flue gas. Through detailed process design and optimization, that takes into account key phenomena such as mass and heat transfer, pressure drop in the bed, we show that that most properties are poor indicators of large-scale process performance. We propose a  framework for rational material selection through detailed process optimization, which can be an effective tool for material selection. The framework is illustrated by comparing the performance of three adsorbents, viz. zeolite 13X, Mg-MOF-74 and UTSA-16.