STORING CO₂ IN MUSCHELKALK

The possibility of storing CO₂ underground in Switzerland is currently being investigated in a scientific project (CITru) led by ETH Zurich. An exploratory phase is underway to examine the geological structure, potential risks, costs and legal framework. If feasibility is confirmed, an initial trial injection of CO₂ could then take place.

The Trüllikon site in the canton of Zurich was chosen because it has a disused borehole from previous investigations by Nagra (National Cooperative for the Disposal of Radioactive Waste) that is in good condition and offers ideal geological conditions: A permeable rock layer (Upper Muschelkalk) that can be injected with CO₂ is overlaid by several impermeable clay layers such as the Opalinus Clay, which prevent the CO₂ from rising.

The current status of the investigations within the framework of CITru can be found on the project website.

SPECIAL ACKNOWLEDGEMENT

We would like to express our sincere thanks to:

• Dr. Gaudenz Deplazes and Beat Stefani from Nagra for lending us the Muschelkalk and anhydrite drill cores from the TRU-1 borehole in Trüllikon free of charge, as well as for their advice and help with transport.
• Dr. Michèle Marti, Simone Zaugg and Stefanie Zeller from the Swiss Seismological Service for providing and adapting the graphics free of charge and for their advice on content.
• Dr. Iwan Stössel from the Earth Science Collections at ETH Zurich for the acquisition and provision of the Muschelkalk handpiece and his advisory input.
• Dr. Alba Zappone from the Institute of Geophysics at the Department of Earth and Planetary Sciences at ETH Zurich, Dr. David Jaeggi and Dr. Martin Ziegler from the Federal Office of Topography swisstopo as well as Dr. Antonio Rinaldi and Prescelli Annan from the Swiss Seismological Service for the acquisition, preparation and transport of the ‘Opalinuston’ drill core from the Mont Terri rock laboratory free of charge.
• Dr. Adrian Gilli, Remy Lüchinger and Léon Frey from the Department Earth and Planetary Sciences at ETH Zurich for their assistance in cutting and preparing the Muschelkalk handpiece.