By bringing seawater into the SeaCURE plant, then dropping its pH we can facilitate the rapid removal of over 90% of that water’s dissolved carbon. We take the liberated CO2 to around 99% purity where it is available for a range of utilisation cases and for geological storage. Increasing the pH of the water and releasing it to the surface ocean, the natural exchange of CO2 between the ocean and atmosphere does the rest, and carbon is sucked out of the atmosphere until the released seawater is chemically indistinguishable from that that was sucked in to the plant – and the atmosphere is one step back towards where it was before we started burning fossil fuels.
The natural concentration of CO2 in seawater is much higher than that in air, such that stripping CO2 from 1 cubic metre of seawater is equivalent to stripping CO2 from 150 cubic metres of air. This means that SeaCURE delivers huge efficiency benefits compared to existing Direct Air Capture techniques. Furthermore, SeaCURE presents opportunities to scale this approach offshore, mitigating the land-use challenges that are potential barriers for other methods of CO2 removal.