Mapping adsorbent properties to optimal process performance of two-bed temperature swing adsorption by superstructure optimization

Abstract

Temperature swing adsorption (TSA) is one of the promising separation techniques for large-scale CO2 capture, and many adsorbents are being developed today. However, it is difficult to identify the optimal operating configurations of multi-bed TSA process to fully utilize the potential of a given adsorbent. This is because optimal operating conditions and cycle configurations are highly dependent on the adsorbent properties. In this work, we propose a comprehensive approach that maps adsorption isotherms to the optimal multi-bed TSA operation identified from various alternatives. A case study for separation of CO2 and N2 is presented where isotherm properties of the adsorbent are parameterized to analyze the influence on the optimal TSA operating cycle configurations and process performance. Our analysis shows that the optimal throughput increases by 68% when the CO2 selectivity is doubled, and 96% when the CO2 selectivity and capacity are both doubled. Furthermore, the frequency of the reflux operations and the cycle time in the optimal operating cycle are found to be dependent on the CO2 capacity.