Predicted binary isotherms of CO2/N2 gas mixture for post-combustion capture and direct air capture using gallate-based metal-organic frameworks

Abstract. Post-combustion capture and direct air capture are two important processes for reducing CO2 content in the atmosphere and mitigating climate change. Post-combustion capture involves capturing CO2 emissions produced from power plants, while direct air capture removes CO2 directly from the ambient air. Gallate-based MOFs can offer remarkable CO2 adsorption capacity. However, there is scarcity of reported works related to N2 adsorption, limiting the scope of research on binary isotherms of CO2/N2 mixture. Therefore, this work aims to investigate the adsorption of pure N2 gas using gallate-based MOFs. Additionally, prediction of binary isotherms of CO2/N2 mixtures was carried out to assess the efficiency of these frameworks for post-combustion capture and direct air capture. The predicted binary isotherms of CO2/N2 mixture revealed that gallate- based MOFs hold potential as adsorbents for both post-combustion capture and direct air capture. The IAST selectivity illustrated that gallate-based MOFs possess the capability to selectively capture CO2 from CO2/N2 mixture, with Mg-gallate exhibiting the highest values, followed by Ni- gallate and Co-gallate. Therefore, Mg-gallate, Co-gallate and Ni-gallate can be suggested as promising adsorbents for post-combustion capture and direct air capture.