Jacobson et al. (2024): Desalination brines as a potential vector for CO2 sequestration in the deep sea

Yitzhak Jacobson, Or M. Bialik, Jacob Silverman, Boaz Lazar, Debora Burd-Villanova, Einat Galilove, Eyal Rahav, Guy Sisma-Ventura IN: Desalination, 574, 117234, https://doi.org/10.1016/j.desal.2023.117234

Freshwater scarcity, driven by population growth and climate change, is increasingly mitigated by seawater desalination, globally. As an energy-intensive process, desalination is a substantial source of atmospheric CO2. Nevertheless, desalination may hold a potential for ocean-based atmospheric carbon removal. Here we describe, for the first time, the carbonate chemistry of desalination brines near the submerged marine outfalls of a large desalination plant, their unique CO2 buffering capacity, and potential for deep sea carbon sequestration. We show that reverse osmosis acts as a carbon concentration factory and that the high-density brine plumes could create a vector for long-term CO2 removal to the deep sea below the seasonal thermocline. At present desalination capacity, we estimate that Desalination Assisted Carbon Concentration (DACC) and CDR could potentially remove 3.8 Mton CO2/year globally, with a negligible contribution to ocean acidification. This mechanism partially mitigates the high carbon print associated with desalination.

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