This week, for the first time, CO2 originating from Switzerland mixed with seawater was injected into the basaltic subsurface in Helguvík, Iceland. This was done to test the subsequent mineralization and thus permanent storage of CO2. The pilot project DemoUpCARMA and its partner project DemoUpStorage have been leading the logistical aspects of this test in close collaboration with the Icelandic partner company Carbfix and the SeaStone project. The research now focuses on monitoring the CO2 injection and mineralization processes.
With the start of the injection of Swiss CO2 in Helguvík, DemoUpCARMA and DemoUpStorage have reached an important milestone. The injection of CO2 dissolved in seawater into the basaltic subsurface at a depth of about 400 m below sea level is being tested for the first time. Previously, the partner company Carbfix has been using fresh water to dissolve the CO2 for the purpose of subsurface mineralization. The task now is to investigate with field tests whether the procedures and mineralization processes work with seawater, which Carbfix in collaboration with the University of Iceland has already demonstrated under laboratory conditions. As part of DemoUpStorage, a comprehensive array of geophysical monitoring techniques will be employed to track mineralization in the basaltic reservoir. Gases dissolved in the fluid will be tracked in continuous mode after injection, thus complementing the geochemical monitoring conducted by Carbfix.
The pilot injection will offer valuable insights for future attempts to inject and permanently store CO2 as carbonate minerals in basaltic structures using seawater, an abundant resource. Oceanic and terrestrial basalts have an enormous theoretical capacity for mineral storage of CO2. Therefore, this method could provide a viable solution for geological storage of significant amounts of carbon dioxide, and thus increasing the contribution of subsurface mineral storage to the goal of achieving the world’s climate targets.
More details about the mineralization process and monitoring methods in the subsurface can be found in our blog text.