European Geothermal Lithium Brine (EuGeLi), launched in January 2019, is a collaborative research and innovation project whose principal aim is to validate an active-solid process co-developed by Eramet, achieve better estimates of lithium reserves contained in European geothermal deposits, and develop a profitable economic model that covers the entire process, from the extraction of the lithium to its refinement into battery-quality products.
A consortium of nine partners, including manufacturers, academic institutions, and research centers, was assembled for this project. Nearly 85% of its €3.9m budget was financed by EIT-Raw Materials, an institution of the European Union.
In May 2021, Eramet and its partner Electricité de Strasbourg announced the success of the first pilot carried out in the geothermal plant of Rittershoffen (close to the border between France and Germany). This was a world premiere.
The project came to an end in December 2021, with the production of the first kilograms of battery-grade lithium carbonate from European geothermal water by the Eramet Ideas teams. The next steps will consist in optimizing the economic model in order to assess whether a competitive lithium production scheme for batteries is possible, on an industrial scale.
The challenge: developing an efficient and eco-friendly extraction process
To carry out this project, a direct extraction unit was installed on the reinjection branch of an existing geothermal well.
This unit is composed of columns filled with the active solid, a pellet-shaped material which serves as a “sponge” that selectively extracts the lithium (loading). Once depleted, the brine may then be reinjected into the sub-soil.
The lithium is recovered by adding low-salinity water to these columns (elution). The result is a concentrated lithium solution that will be purified before precipitating the battery-quality lithium carbonate.
This direct extraction process was developed for the Lithium Project in Argentina. The active material was formulated to be used at room temperature and atmospheric pressure.
The main challenge of the EuGeLi project was to adapt the process to European geothermal brines and their operating conditions, particularly the temperature and pressure conditions of the reinjection branch (80°C, 20 bars).
Additionally, since the pumped-up brine is subsequently reinjected into the sub-soil, the lithium extraction process must not under any circumstances impact or disrupt the natural environment of the sub-soil.
Lastly, the end-product of the process, lithium carbonate, must be extremely pure in order to be used in lithium-ion batteries.
Activities performed during the project
The project was divided into three major and interconnected workstreams:
- The first workstream focused on evaluating the lithium deposits contained in European geothermal water. This assessment addressed issues related to the origin of the lithium and attempted to establish predictive models based on geological parameters, including the temperature of the water and the make-up of sub-soil rocks.
- The goal of the second workstream was to develop the direct extraction process. First, the active material used to capture the lithium from the brine was optimized at laboratory scale, so that it might be used in geothermal temperature and pressure conditions. Next, the material was produced at a semi-industrial scale, and two direct extraction pilot tests were conducted on a geothermal well in Alsace, in order to produce a concentrated lithium solution. The last pilot test was conducted at the Eramet Ideas center, in order to produce the lithium carbonate using the concentrated solution from the initial pilot tests. The objective in this case was to assess the technical and economic feasibility of the process.
- Lastly, the results of the first two workstreams fed into a study that established various economic models for producing lithium from geothermal deposits. This study was designed to assess the overall profitability and feasibility of an industrial project for lithium and energy co-production.