Efficient Direct Air Capture in Industrial Cooling Towers Mediated by Electrochemical CO 2 Release

• Published in: Angewandte Chemie International Edition Vol. 64; no. 5; p. e202412697
• Main Authors: Zheng, Ao‐Chuan, Zou, Ye‐Bin, Du, Lin, Zhang, Qiang, Daasbjerg, Kim, Hu, Xin‐Ming
• Format: Journal Article
• Language: English
• Published: Germany 27.01.2025
• Subjects: Direct air capture; Scalability; Industrial cooling tower; Electrochemical CO2 release; Buffered absorbent solution
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202412697

Direct air capture (DAC) is a promising technology for mitigating global climate change but suffers from low efficiency, small scale, and high cost due to the dilute atmospheric CO 2 , limited size of air contactors, and heat‐driven CO 2 release. Here, we propose combining DAC with widely used industrial cooling towers to extract CO 2 from the air and using electrolysis to release the captured CO 2 at room temperature. We first prepare a buffered absorbent solution consisting of sodium glycinate, glycine, and sodium chloride for effective CO 2 capture from the air, solving the incompatibility problem of the cooling towers with conventional absorbents. Next, we employ a three‐chamber electrolyzer for efficient release (≥95 %) of the captured CO 2 with high purity (≥98 %) by constant current electrolysis at room temperature, bypassing the conventional energy‐intensive heating process. The entire DAC system can operate stably for multiple cycles, and the mechanism for consecutive CO 2 capture and release is uncovered. This work reveals the great potential of running DAC in industrial cooling towers coupled with electrochemically‐driven CO 2 release, opening up new avenues for curbing the increasingly severe climate change.