A review of CO2 adsorbents performance for different carbon capture technology processes conditions

The utilization of various conventional and emerging solid adsorbents is an attractive carbon capture method for post-combustion and direct air capture (DAC). This review aims to identify adsorbents with the highest CO2 adsorption performance at various CO2 capture conditions inclusive of pre-combustion, post-combustion, and DAC to aid the selection of adsorbents. It presents the various adsorbents' physical and chemical properties, their synthesis methods, CO2 adsorption performance, and their advantages as CO2 adsorbents. Findings of the review show that NaX@NaA core-shell microspheres possess the highest CO2 adsorption capacity at 5.60 mmol g(-1) for adsorption at DAC conditions. MOF-177-TEPA exhibited the highest post-combustion condition CO2 adsorption capacity at 4.60 mmol g(-1) given tetraethylenepentamine properties leading to low diffusion resistance for CO2 and easy access to active sites. Approximation of these adsorbents' adsorption capacity within pre-combustion capture temperature at 1 bar for oxy-combustion process was 0.0000026-48.71 mmol g(-1). It is crucial to understand and evaluate these adsorbents' characteristics for application in the appropriate adsorption conditions. This considers their usage limitations on pilot-scale CO2 capture because of low productivity, poor durability, and stability for prolonged cyclic adsorption-desorption, expensive adsorption system, high gas flow rate, high adsorbate accommodation requirement, longer flow switching time, and low tolerance towards water and impurities present in flue gas. This paper hence presents future enhancements in overcoming their limitations to accommodate pilot scale carbon capture. These are beneficial in providing insights for capturing CO2 from flue gases emitted in industries. (c) 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.