CarbFix is a CCS consortium operated by RE, UI, Columbia University (USA) and CNRS (France). On this site, partner RE, in an attempt to mitigate the environmental impact of its geothermal processes, achieved one of the most successful and best-known examples of CO2 sequestration processes in the world. RE operates over 100 wells at Hellisheidi, about 10 of which are used for re-injection of geothermal water, one is used for re-injection of captured gases, the others are production and monitoring wells. S4CE will access a field site in which CO2-H2S-water plumes are injected in the sub-surface. Roughly one-third of the CO2 and H2S presently emitted from the Hellishidi power plant is being injected as a dissolved water phase into fractured basaltic rocks.
This will be further up-scaled as part of the S4CE project. Critical to the S4CE success is to
- monitor the fate of the injected dissolved acid gases; preliminary work suggests the majority of the injected carbon and sulphur are converted to stable minerals though reactions with the host rock within 3 to 6 months. The degree to which this changes over the long-term, and due to up-scaling will be assessed to verify the sustainability of this carbon storage method, and
- determine the degree to which increased water/CO2/H2S injection can induce seismicity in the basaltic host rocks. Micro-seismic data, collected by the Icelandic Geologic Survey, will be available to S4CE. One or more wells will be used for injection and a minimum of 3 for monitoring. S4CE will monitor the CO2/H2S plume via water sampling, and will assess the long-term stabilization of the fluids via the formation of carbonate minerals. Baseline monitoring will be available. Further efforts will be made towards expanding this method to the injection of acid gases with seawater into submarine basalts. This latter effort will include laboratory experiments of seawater-CO2-basalt interactions, and a baseline study on a new subsurface site. Fluid samples collected from deep in the wells will be tested for water quality assessment by UNINA.