European Geothermal Lithium Brine (EuGeLi) 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, which began in January 2019 and will conclude in December 2021. Nearly 85% of its €3.9m budget was financed by EIT-Raw Materials, an institution of the European Union. As the project progresses, five weeks of pilot testing will be conducted at a geothermal plant in Alsace in order to evaluate the process.
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 is 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 is divided into three major and interconnected workstreams:
- The first workstream focuses on evaluating the lithium deposits contained in European geothermal water. This assessment addresses issues related to the origin of the lithium and attempts 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 is to develop the direct extraction process. First, the active material used to capture the lithium from the brine will be optimized at laboratory scale, so that it may be used in geothermal temperature and pressure conditions. Next, the material will be produced at a semi-industrial scale, and two direct extraction pilot tests will be conducted on a geothermal well in Alsace, in order to produce a concentrated lithium solution. The last pilot test will be 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 is to assess the technical and economic feasibility of the process.
- Lastly, the results of the first two workstreams will feed into a study that will establish various economic models for producing lithium from geothermal deposits. This study is designed to assess the overall profitability and feasibility of an industrial project for lithium and energy co-production.