Basin scale modeling of water chemistry changes by hydrothermal leaching applied for the lithium-rich brines of the Rhine graben

The geochemical composition of water can have a strong impact on the viability of geothermal resource exploration. Depending on its elements, it can cause scaling or corrosion problems or on the contrary, present opportunities for the recovery of co-products such as Lithium. In this thesis, it is proposed to characterize the chemistry of the fluids taking into account the phenomena of hydrothermal leaching during the geological evolution of the basin. The approach proposed in this PhD is based on the joint use of evolutionary geological models (basin models), which allows  improving knowledge of the physical factors (temperature and pressure) controlling reactive and hydrodynamic transfers and reactive transport models that allows improving the understanding of the mobilization and remobilization of chemical species. The selected application case is the Rhine graben, which is highly documented, has a high geothermal potential and has the particularity of having lithium-rich brines. The data necessary for the construction and calibration of the geological model and the hypotheses concerning the paleo-circulation of hydrothermal fluids are available in the literature. For the reactive transport model, data concerning the hydrothermal alteration of granites and the behaviour of the major chemical species are available, but the dissolution kinetics of lithiniferous minerals are scarse. The thesis will therefore also include experiments at Université de Lorraine to acquire new kinetic data of the lithium dissolution.

Keywords: geological modelling, numerical modelling, fluid-rock interaction, mineral geochemistry

• Academic supervisor    Prof. STERPENICH Jérôme, GeoRessources, Université de Lorraine 
• Doctoral School    Sciences et Ingénierie des Ressources Naturelles, http://doctorat.univ-lorraine.fr/fr/les-ecoles-doctorales/sirena/presentation 
• IFPEN supervisor    Dr. LEMGRUBER-TRABY Adriana and Dr. COLLARD Nathalie, Direction Sciences de la Terre et Technologies de l'Environnement, adriana.traby@ifpen.fr
• PhD location    IFP Energies nouvelles, Rueil-Malmaison, France   
• Duration and start date    3 years, starting in the fourth quarter 2023
• Employer    IFP Energies nouvelles, Rueil-Malmaison, France
• Academic requirements    University Master's degree in Earth Sciences
• Language requirements    Fluency in French or English, willingness to learn French
• Other requirements    The doctoral student must have a strong interest in modelling and good knowledge of physics and chemistry (geosciences).