Amine-based sorbents for CO2 capture from air and flue gas—a short review and perspective

• Published in: Research on chemical intermediates Vol. 49; no. 3; pp. 791 - 817
• Main Authors: Huhe, FNU, King, Jaelynne, Chuang, Steven S. C.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.03.2023; Springer Nature B.V; Springer
• Subjects: Adsorption; Ambient temperature; Carbon dioxide; Carbon sequestration; Catalysis; Chemistry; Chemistry and Materials Science; Flue gas; Functional groups; Inorganic Chemistry; Physical Chemistry; Polymers; Sorbents; Porous polymers; Thermal swing; Immobilized amine; Vacuum swing; Direct air capture (DAC); Mechanism
• ISSN: 0922-6168; 1568-5675
• DOI: 10.1007/s11164-022-04902-7

This review briefly examines the current state of amine-based and polymer sorbents as well as highlights the structure of strongly and weakly adsorbed CO 2 intermediates on amine-based sorbents and their roles in thermal swing adsorption (TSA) and vacuum swing adsorption (VSA) CO 2 capture process. Weakly adsorbed CO 2 sites on amine sorbent allow amine sorbents to be regenerated by vacuum evacuation at ambient temperature (i.e., VSA) while strongly adsorbed CO 2 sites must be regenerated by heating the sorbent (i.e., TSA). This perspective discusses key issues regarding thermal swing and pressure/vacuum sorbents for CO 2  capture, the mechanism of CO 2  adsorption on amine sorbents, and the methodology for sorbent development. The perspective also provides a direction for further improving amine sorbents and processes for CO 2  capture and suggests that amino-porous and polymer sorbents operated in a vacuum-assisted thermal swing (V/TSA) mode could lead to a cost-effective CO 2  capture process. To facilitate the development of effective amine sorbent CO 2  capture processes, the design and fabrication of porous sorbents should be considered at various length scales: (i) the structure of amine sites and their neighboring functional groups at a nanometer scale in the sorbent particle to reduce the CO 2 binding energy on amine sites, (ii) incorporation of the amine sorbent particles into the internal structure of the adsorber at a centimeter and meter scale, (iii) the mode of the adsorber operation, (TSA/PSA/VSA/TVSA), and (iv) the composition of the CO 2 -containing feed stream. Mitigating CO 2 -induced global climate changes calls for cost-effective approaches for capturing CO 2 . This short review unravels the current limitations of amine-based sorbent and porous polymer for CO 2  capture. The perspective offers several thoughts and approaches to address the scientific/technical issues at each level from nanometer to meter scale in the development of sorbent and polymer-based CO 2 capture process. Graphical abstract