Galeczka et al. (2026): Geochemical framework for CO₂ mineralization in coastal aquifers: Lessons from the Coda Terminal project, Iceland

Iwona Galeczka, Martin Voigt, Daniel Andres Duque Carrillo, Kjartan Marteinsson, Thomas Ratouis, Sandra Ósk Snæbjörnsdóttir, Fríða Jónsdóttir, Paula Fernandez-Acosta, Gunnar Hrafn Gunnarsson, Bergur Sigfússon, Jóhann Gunnarsson Robin et al., IN: International Journal of Greenhouse Gas Control, https://doi.org/10.1016/j.ijggc.2025.104565

Freshwater scarcity can limit the scalability of subsurface CO₂ mineralization projects which rely on dissolving CO₂ in water before injection into basaltic reservoirs. While ongoing Carbfix projects primarily use freshwater or process water such as geothermal condensate to dissolve CO₂, in the Coda Terminal project, in Straumsvík, SW Iceland, it is proposed to use seawater due to its availability. The storage reservoir contains a mix of freshwater, brackish, and saline groundwater, with measured conductivities ranging from ∼100 to ∼40,000 μS/cm. Water chemistry of the brackish and saline water indicates extensive water-rock interaction with depletion of Na, K, B, and Mg, and strong enrichment in Ca – essential for calcite precipitation, the dominant carbonate mineral in low-temperature basalt alteration.

LINK