This postdoctoral research project focuses on modeling the extraction of lithium from geothermal brines in the Upper Rhine Graben (URG). This resource is critical for France's energy transition and electric vehicle battery production. In collaboration with BRGM (the French Geological Survey) and Lithium de France, the project aims to understand the mechanisms of natural lithium enrichment in deep geological reservoirs and to optimize sustainable extraction methods.
The research will develop 3D coupled thermo-hydrodynamic-geochemical simulations to predict the long-term impacts of geothermal reservoir exploitation, including hydrodynamic, thermal, and chemical disturbances. The core technical challenge involves coupling two specialized codes: ComPASS (for thermohydrodynamic modeling in fractured media) and PhreeqC (for geochemical modeling), using a sequential non-iterative approach (SNIA). These simulations will account for the complex, reciprocal effects of thermal, hydrodynamic, and geochemical processes, including the changes in porosity and permeability caused by dissolution and precipitation reactions, which are enhanced by temperature variations. ComPASS allows for multiphase and multicomponent hydrothermal transfer simulations on unstructured meshes with complex fracture networks. PhreeqC handles geochemical reactions and mineral equilibria. The development of the coupling will rely on existing literature and will leverage an existing library (PhreeqcRM). The coupling will implement mass, heat, and charge balances while considering the effects of fluid chemistry changes on rock properties and fluid circulation.
This position requires teamwork skills, expertise in Python programming (knowledge of C++ is a plus), and experience in coupled process modeling, particularly in reactive transport and hydrothermal modeling.
