Sorption and ion exchange as direct lithium extraction (DLE) techniques are considered the most promising processes for use in geothermal power plants. To be successfully applied, DLE techniques must be able to both extract lithium from complex brines with high ion concentrations and simultaneously meet site-specific, geothermal operating conditions.
As part of the UnLimited joint project, the Institute of Applied Geosciences at KIT is working on the selection of particularly qualified lithium-selective sorbents. In this context, not only the material properties of the respective adsorbents have to be considered, but also their environmental compatibility during production, use, and recycling.
The research team led by Professor Jochen Kolb has specialized in the investigation of inorganic sorbents. Thereby, the focus of his work is the evaluation of the effectiveness of the investigated sorbents for large-scale lithium extraction within geothermal operating conditions.
Results to date show that lithium manganese oxide, iron phosphate and zeolites in particular are promising sorbents for environmentally friendly, efficient and selective lithium extraction. Further information may be obtained here.
Optimizing the performance of the sorbents so that they can make a significant contribution to reducing the costs of the DLE processes will be a key issue in the future.