Hierarchical porous carbon beads for selective CO2 capture

• Published in: Journal of CO2 utilization Vol. 51; p. 101659
• Main Authors: Jung, SuYeong, Lee, Jae-Rang, Won, Yooseob, Lee, Dong-Ho, Park, Young Cheol, Bae, Youn-Sang, Kim, Hyunuk
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2021
• Subjects: CO2 adsorption; Hierarchical porous carbon; K+ ion exchange; Phenol formaldehyde resin; Phenol formaldehyde resin; Hierarchical porous carbon; CO2 adsorption; K+ ion exchange
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2021.101659

[Display omitted] •Hierarchical porous carbon beads were prepared from K+-exchanged phenolic resin.•Porous carbon beads have interconnected micro- and mesopores.•K2CO3-treated CPFR beads adsorbed 7.80 wt% CO2 at 0.15 bar and 298 K.•The ideal CO2/N2 selectivity of K2CO3-treated CPFR beads at room temperature is 52.6.•K2CO3-treated CPFR beads selectively adsorb 5.5 wt% of CO2 over N2. Excessive CO2 emissions from increased energy consumption are causing an environmental disaster that threatens humanity. Herein, we report the development of hierarchical porous carbon beads with interconnected micro- and mesopores for selective CO2 capture. Hierarchical porous carbon beads were prepared by the carbonization of potassium-exchanged phenol formaldehyde resin (PFR) beads obtained from exchange of K+ to the PFR OH groups. Interestingly, the carbonized K2CO3-treated PFR (CPFRs) exhibited notably high surface areas and total pore volumes with interconnected micro- and mesopores. Based on their high porosities and nitrogen contents, the K2CO3-treated CPFR beads adsorbed 7.80 wt% CO2 at 0.15 bar and 298 K, which is an adsorption result that is much higher than those (4.41 wt% and 5.33 wt%) of pristine and KOH-treated CPFR beads, respectively. More importantly, the ideal CO2/N2 selectivity (52.6) of K2CO3-treated CPFR beads, as determined by Henry’s constant at room temperature, is superior to those (24.2 and 28.6) of pristine and KOH-treated CPFR beads, respectively. Breakthrough experiments with 15 % CO2 in N2, which has a similar partial pressure to the CO2 partial pressure in flue gases from coal power plants, revealed that K2CO3-treated CPFR beads selectively adsorb 5.5 wt% of CO2 over N2. This selective CO2 capacity is superior to those reported in other porous carbon materials. Therefore, to reduce CO2 emissions, hierarchical porous carbon beads with interconnected micro- and mesopores can play an important role in CO2 capture and separation.