Quantitative modeling and assessment of CO<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msub><mml:mrow/><mml:mn>2</mml:mn></mml:msub></mml:math> storage in saline aquifers: A case study in Switzerland

The global temperature rise necessitates urgent action to reduce greenhouse gas emissions, with Geological Carbon Storage (GCS) emerging as a promising strategy. GCS involves injecting CO 2 into deep geological formations, particularly saline aquifers. However, ideal reservoir conditions, such as stable caprock and adequate storage capacity, are rare in regions like Switzerland. This study assesses the CO 2 storage potential in the saline aquifer at Triemli, Switzerland, aiming to explore the feasibility of decentralized, small to medium-scale storage with multiple injection points in geologically unfavorable areas. Through numerical simulations, we investigate CO 2 injection, migration, and long-term reservoir stability, bridging the gap between theoretical estimates and practical feasibility. Our findings highlight the potential of deep saline aquifers in the Swiss Molasse Basin and Folded Jura for CO 2 storage, with the study area capable of storing approximately 2 million tons of CO 2 over 30 years. Advanced injection techniques could increase this capacity to 3 million tons. These results underscore the importance of reservoir properties in optimizing CO 2 storage and provide crucial insights for guiding future GCS efforts in Switzerland and beyond, supporting informed decision-making and the implementation of decentralized storage projects.