An experimental strategy for evaluating the energy performance of metal–organic framework-based carbon dioxide adsorbents

Abstract

Recently, metal–organic frameworks (MOFs) have attracted great interest in the field of carbon capture and storage (CCS) as promising carbon dioxide (CO2) adsorbents. The energy performance in relation to the regeneration process is a crucial factor when screening for suitable CCS MOF adsorbents. However, few experimental methods have been reported for evaluating the energy requirements for their regeneration. Herein, we proposed an experimental strategy to investigate the energy performance of MOF adsorbents for CO2 capture in the temperature swing adsorption (TSA) process using a combination of calorimetry and thermal analysis method. Five well-characterized isomorphic zirconium-based MOFs (University of Oslo 66-X, where X = H, NH2, (OH)2, C4H4, or NO2) were reliably evaluated using this strategy. The energy parameters related to regeneration, including specific heat capacities, thermodynamic functions, desorption temperatures, regeneration energy, CO2 working capacities, and parasitic energy, were accurately determined for these MOFs. The results indicated that the key determinants for the regeneration energy efficiency of CO2 adsorbents were their specific heat capacities and CO2 working capacities during a TSA cycle. More importantly, the proposed strategy may provide a feasible and effective experimental approach to study and evaluate the potential of adsorbents for CO2 capture.