Neptune Energy advances direct lithium extraction in Germany

The pilot unit’s three parallel adsorption columns allow lithium ions to be adsorbed and desorbed almost simultaneously in an oxygen-free process

(Image courtesy of Neptune Energy)

Neptune Energy has moved its Altmark lithium project into Pilot Phase II, working with Fraunhofer IEG to test adsorbent materials in a dedicated direct lithium extraction unit. Evonik Catalysts has been selected to supply the first material, an adsorbent branded Liocel, following earlier pilot work comparing ion-exchange and adsorption processes. For a European battery supply chain still building out domestic lithium sources, the adsorbent evaluation running through the coming months carries more procurement relevance than the milestone announcement alone.

What the pilot unit actually does

The DLE pilot plant, developed by Fraunhofer IEG, processes up to 1,000 litres of geothermal brine per day, drawn from thermal water in which lithium is dissolved at depths of 3,000 to 4,000 metres in northern Saxony-Anhalt. Three adsorption columns run in parallel, letting adsorption and desorption of lithium ions happen almost simultaneously in an oxygen-free environment, and the resulting lithium chloride solution then requires further processing into battery-grade lithium carbonate or lithium hydroxide monohydrate.

That processing route follows on from earlier pilot work, in which Neptune tested both ion-exchange and adsorption. Evonik’s Liocel adsorbent demonstrated stability and strong performance in preliminary trials, the company says, which carried it forward as the first material for evaluation in Pilot Phase II, with Evonik also providing on-site application and process expertise. Michael Frey, the company’s Vice President and Head of Process Catalysts & Adsorbents, said the partners will further evaluate adsorption-based lithium extraction under the specific conditions of the Altmark resource, drawing on that on-site expertise as testing proceeds.

Regulatory groundwork already in place

This pilot phase builds on an extraction approval the Saxony-Anhalt mining authority granted Neptune in April 2024, though further mining permits will still be required before the project can advance to a demonstration phase. What that approval covers is substantial by European standards: a resource estimated at 43 million tonnes of lithium carbonate equivalent, among the largest project-specific lithium resources Neptune says exist globally. Neptune commissioned Sproule ERCE to assess the resource base under the CIM/NI 43-101 standard, and it’s from that work that the 43-million-tonne estimate comes.

Where the environmental case still needs data

Neptune positions DLE from brine as an alternative to two established extraction methods, hard-rock mining as practised in Australia and evaporation-pond brine extraction as practised in Chile, avoiding open-pit excavation in the first case and large evaporation ponds in the second. The full environmental picture will depend on factors including energy use, reagents, water management and reinjection, all of which vary between projects. Specific CO2-per-tonne figures for the site are not yet public, and a related research effort, RoLiXX, is now working to build out that picture. Running a life-cycle assessment of Rotliegend-basin lithium extraction over 36 months, with a project volume of around three million euros funded through the Federal Ministry of Research, Technology and Space, RoLiXX brings together Neptune, the GFZ Helmholtz Centre, TU Berlin, Fraunhofer IEG and the Institute for Ecological Economy Research, and its findings should give procurement teams the site-specific data to support the sustainability case going forward.

Pilot testing ahead of the 2030 target

Neptune plans to follow this pilot phase with a demonstration phase, subject to further mining permits, ahead of a target to begin commercial production from 2030, when the company’s ambition is to reach up to 25,000 tonnes of lithium carbonate equivalent annually during the 2030s, enough, Neptune estimates, to supply battery material for around 500,000 electric vehicles a year. The material evaluation running through the coming months is an early step toward that goal, narrowing down which adsorbent is suited to industrial-scale deployment before any potential decision on a full extraction plant.