The hydro-geochemistry working group uses isotopic tracing and numerical models to study material transfer related to fluid-rock interactions in geothermal systems. The group also studies microbiology in geothermal contexts and the kinematics of mineral alteration.
Achievements
Hydrogen production coupled with geothermal heat/electricity generation could boost the profitability of the deep geothermal sector. Moreover, areas of the lithosphere that have already been drilled, i.e. deep geothermal sites, offer unique opportunities for research into the potential production of native H2. A. Wallentin, a new PhD student funded by the ITI GeoT, has been working since October 2023 on laboratory experiments and geochemical modelling aimed at simulating water-rock alteration to better understand the possibility of producing native H2 at the Soultz-sous-Forêts site. To understand the conditions of the redox reaction that produces native H2 in granites [1], experiments in gold capsules are being carried out at ITES [2]. To stimulate the reaction and see the influence of CO2 pressure on the system, experiments with CO2 injection are being set up in collaboration with the Fraunhofer Institut in Bochum, Germany. Finally, as H2 is highly volatile, we will be looking for traces of an active source in the Rhine Graben by carrying out field campaigns to measure H2 at the surface, in collaboration with the Terrensis company.
The group is also highly involved in multiple high scope project such as PEPR sous-sol PC9 and the ANR AlterAction.
Figure 1. Photograph of a Soultz-sous-Forêts granite carrot and a lamina rich in ferrous minerals capable of producing H2 (biotite (Bt), magnetite (Mg), chlorite (ChL) and hornblende (Hbl)
Figure 2. Gold capsules filled with pure soldered biotite and Parr 5500 reactors for high-temperature and high-pressure experiments
Figure 3. Laboratory alteration experiment (a) X-ray scanner segmentation of the sample (2 cm wide) before fluid circulation, showing the network of interconnected fractures created by dynamic loading (yellow), and Fe-oxide titanite and allanite grains (blue), rich in rare earth elements (b) Alteration gradient in thin cross-sectional sections of the sample, after 3 months of reactive fluid percolation at 180°C
Team
Leader: Damien Lemarchand & Jesica Murray
Members: Bertrand Fritz, Yann Lucas
- Post-doc: Jesica Murray
- PhD: Anna Wallentin
Collaborations
With the other ITI GeoT WGs:
WG9: Modelling
With other academic partners:
Mai-Lin Dohan and Laurent Truche (ISTerre, Grenoble, France)
Antonin Richard and Jacques Pironon (GeoRessources, Nancy, France)
Thomas Reinsch and Mathias Nehler Fraunhofer IEG (Research Institution for Energy Infrastructures and Geothermal Systems, in Bochum, Germany)
Florian Ossenlin at ISTO (Institute des Science de la Terre d’Orleans, Orleans, France)
Sophie Opfergelt (Earth and Life Institute - environmental sciences Université Catholique de Louvain, Belgique)
Claudine Noguera (Institut des nanosciences de Paris, France)
With socio-economic partners:
Terrensis SAS
ES
Publications
Silicic volcanic rocks, a main regional source of geogenic arsenic in waters: insights from the Altiplano-Puna plateau, Central Andes. Murray, J. Guzmán, S., Tapia, J. Nordstrom, D.K. (2023). Chemical Geology. https://doi.org/10.1016/j.chemgeo.2023.121473
Towards a comprehensive understanding of the origin, distribution, and biogeochemistry of arsenic in the Altiplano-Puna plateau of South America with the IGCP-707 project. Murray, J., Tapia, J., Ormachea, M., Tirado, N., Nordstrom, D. K. (2023). EPISODES Journal of International Geoscience. https://doi.org/10.18814/epiiugs/2023/023017