Alkalinity Concentration Swing for Direct Air Capture of Carbon Dioxide. Issue 20 (2nd September 2021)

• Record Type: Journal Article
• Authors: Rinberg, Anatoly; Bergman, Andrew M.; Schrag, Daniel P.; Aziz, Michael J.
• Is Part Of: ChemSusChem. Volume 14:Issue 20(2021)
• Page Start: 4439
• Page End: 4453
• Publication Date: 2021-09-02
• Subjects: carbon dioxide removal -- direct air capture -- reverse osmosis -- capacitive deionization -- sustainable chemistry; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202100786
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: The alkalinity concentration swing (ACS) is a new process for direct air capture of carbon dioxide driven by concentrating an alkaline solution that has been exposed to the atmosphere and loaded with dissolved inorganic carbon. Upon concentration, the partial pressure of CO2 increases, allowing for extraction and compression. Higher concentration factors result in proportionally higher outgassing pressure, and higher initial alkalinity concentrations at the same concentration factor outgas a higher concentration of CO2 . Two desalination technologies, reverse osmosis and capacitive deionization, are examined as possible ACS implementations, and two corresponding energy models are evaluated. The ACS is compared to incumbent technologies and estimates for water, land, and energy requirements for capturing one million tonnes of CO2 per year are made. Estimates for the lower end of the energy range for both approaches compare favorably to other approaches, such as solid sorbent and calcining methods. Abstract : Direct air capture of CO 2 through desalination : The alkalinity concentration swing (ACS) is a new process for direct air capture of carbon dioxide based on concentrating an alkaline aqueous solution (see image, Step 12) that has absorbed atmospheric CO2 (Step 41), and which leverages desalination technologies, such as reverse osmosis and capacitive deionization.