Scavenging and Mineralization of CARbonic Acid at InterFACE

• Applicant: Professor Dr. Denis Gebauer
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Solid State and Surface Chemistry, Material Synthesis
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569039102

CO2 direct removal and storage is vital to moderate the future global temperature rise. On geological time scales, the ocean has been mitigating atmospheric carbon dioxide levels through the precipitation and subsequent redissolution of calcium carbonate. Still, this slow equilibrium cannot cope with the recent vast release of anthropogenic CO2 in the air. SCARFACE aims to harness the rapid mineralization of CO2 by employing out-of-equilibrium physical chemistry. We build on our recent observation that trains of air bubbles injected into saline water are stabilized by the spontaneous transformation and clusterization of CO2 into transient surface-active bicarbonate species. We propose that non-equilibrium chemistry at the gas-water interface can promote the rapid transformation of these clusters into crystalline carbonates. This carbon removal shortcut is chemical-free and could be scaled up to vast extents. This fundamental approach introduces a new paradigm of intertwined out-of-equilibrium physical chemistry and chemistry at air-water interfaces, addressing a significant new approach to enhancing CO2 sequestration while mitigating ocean acidification. SCARFACE is built upon three pillars, which will be carried out in parallel. In a first colloidal approach, we will explain how diffusion and clusterization of dissolved CO2 occur at the air/water interface. In a second chemical approach, we will unravel the ionic chemistry at the surface of microbubbles to produce first amorphous and then crystalline calcium carbonate, which ultimately stabilizes hollow microcapsules. Finally, we will develop dedicated microfoaming experiments in microfluidic devices and autoclave reactor to model the mineralization process under various ocean-like conditions, including temperature and pressure variations at different depths.

• DFG Programme: Research Grants
• International Connection: France
• Cooperation Partner: Dr. François Ganachaud