Articles | Volume 20, issue 4
Research article
20 Feb 2023
Research article |  | 20 Feb 2023

Stability of alkalinity in ocean alkalinity enhancement (OAE) approaches – consequences for durability of CO2 storage

Jens Hartmann, Niels Suitner, Carl Lim, Julieta Schneider, Laura Marín-Samper, Javier Arístegui, Phil Renforth, Jan Taucher, and Ulf Riebesell

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Cited articles

Bach, L. T., Gill, S. J., Rickaby, R. E. M., Gore, S., and Renforth, P.: CO2 Removal With Enhanced Weathering and Ocean Alkalinity Enhancement: Potential Risks and Co-benefits for Marine Pelagic Ecosystems, Front. Clim., 1, 1038,, 2019. 
Badocco, D., Pedrini, F., Pastore, A., di Marco, V., Marin, M. G., Bogialli, S., Roverso, M., and Pastore, P.: Use of a simple empirical model for the accurate conversion of the seawater pH value measured with NIST calibration into seawater pH scales, Talanta, 225, 122051,, 2021. 
Bonfim-Rocha, L., Silva, A. B., Faria, S. H. B. D., Vieira, M. F., and Souza, M. D.: Production of Sodium Bicarbonate from CO2 Reuse Processes: A Brief Review, Int. J. Chem. React. Eng., 18, 1883,, 2019. 
Brečević, L. and Nielsen, A. E.: Solubility of amorphous calcium carbonate, J, Cryst. Growth, 98, 504–510,, 1989. 
Short summary
CO2 can be stored in the ocean via increasing alkalinity of ocean water. Alkalinity can be created via dissolution of alkaline materials, like limestone or soda. Presented research studies boundaries for increasing alkalinity in seawater. The best way to increase alkalinity was found using an equilibrated solution, for example as produced from reactors. Adding particles for dissolution into seawater on the other hand produces the risk of losing alkalinity and degassing of CO2 to the atmosphere.
Final-revised paper