IKKA-CCUS aims to demonstrate a novel modular crystallisation process for carbon capture and utilisation (CCU) based on ikaite formation (CaCO3·6H2O), inspired by natural processes in cold marine environments. The project is based on the hypothesis that a membrane-based system using seawater, carbonate chemistry and flue gas can efficiently precipitate ikaite and convert it into pure calcium carbonate, while achieving scalable, low-energy CO2 capture.
The project will construct and operate a 2-3-container demonstration plant at an industrial coastal site in Denmark. CO2 is first absorbed into alkaline seawater, altering the carbonate balance. The CO2-enriched solution is then mixed with fresh, calcium-rich seawater across membrane surfaces, where ikaite precipitates and grows directly on the membrane. The system will be tested with raw, scrubbed and biogenic flue gas to evaluate performance across multiple sources. Analytical and optimisation activities will assess gas capture efficiency, water chemistry and mineral output. End-users from the paint and plastics sectors will validate the produced CaCO3 solids. Finally, Topsoe and Valmet will develop a roadmap and simulate electrolysis integration for future industrial-scale plants.
The project will deliver proof of concept for ikaite-based CO2 capture under real-world conditions, generate more than 1,000 kg of CaCO3 for industrial validation and provide key datasets for environmental and techno-economic assessments. This will lay the foundation for scalable, decentralised CO2 capture with integrated utilisation, aligned with Denmark’s CCUS goals.
