GeoLit Project - Geothermal Energy and Lithium Co-production

The significant presence of lithium (Li) in geothermal brines, combined with increasing Li demands [2], opens for co-production of geothermal energy and Li. In Europe, several geothermal areas have Li-rich brines (Figure 1), providing opportunity for a European domestic supply chain for Li. Based on promising results for the extraction of Li from produced geothermal brines [4], the first pilot plants for co-production are currently being developed. These are related to geothermal projects under development or in operation in the Upper Rhine Graben [5], which is considered Europe’s most promising area for geothermal Li production [1].  In this region, high Li contents of more than 150 mg/L are reported for several brines (Figure 1). However, the potential of co-production over the entire lifetime of an engineered system, including the effect of reinjection of heat and Li depleted geothermal fluids in heterogeneous and fractured reservoirs, is yet unclear. Addressing this gap requires 1) simulation tools for relevant non-isothermal compositional multiphase flow and reactive transport regimes in fractured porous media and 2) experimental investigation of the geochemical behaviour of Li at relevant conditions, neither of which are currently available. This knowledge need arises from limitations in our understanding of Li remobilization rates at relevant temperature-pressure conditions, requiring specialized high T-P experimental infrastructure, and limitations in mathematical models and related tools, which requires development of advanced tools building on state-of-the art models and numerical solution schemes.