Vulcan Energy Resources Limited has successfully developed, tested and demonstrated its own in-house lithium extraction sorbent, VULSORB, for sustainable lithium extraction from the Upper Rhine Valley Brine Field and the Zero Carbon Lithium Project. (Earlier post.)
VULSORB demonstrated higher performance and lower water consumption for lithium extraction in Vulcan’s pilot plant, compared with commercially available sorbents tested by the Company. Test work has been carried out on live brine from Vulcan’s commercially operating geothermal renewable energy plant, Natürlich Insheim.
The manufacturing process for VULSORB has been shown to be environmentally benign, with many of the reagents recycled and with opportunities for Vulcan to use its own produced lithium to manufacture future sorbent once in production, thus further reducing Vulcan’s carbon footprint and operating costs while fulfilling the European Union’s circular economy goals.
VULSORB is a variation of the type of lithium extraction sorbents originally developed thirty years ago and used commercially around the world for lithium extraction from brine for the last 25 years. This Technology Readiness Level (TRL) 9 approach for lithium extraction can be used in most lithium-rich brines globally, provided salinity in the brine is high enough and there is sufficient heat to drive the process, with a brine pre-treaent step to increase sorbent durability which can be adjusted depending on local brine chemistry.
The sorbent enables the lithium to be extracted selectively from the brine, providing a very pure lithium chloride eluate which can then be electro-chemically converted to lithium hydroxide for use in lithium-ion batteries in the European cathode, battery, and automaker industries. Vulcan has binding lithium hydroxide offtake agreements with Stellantis, Volkswagen, Renault, LG Energy Solution and Umicore.
This process is much faster and more efficient, with a lower carbon footprint, than the legacy industry method of using large-scale evaporation and large quantities of chemical reagents to extract the lithium and process into lithium hydroxide6. The sorbent extraction happens in hours, rather than up to 18 months7 as is the case with legacy extraction routes, allowing Vulcan to quickly respond to the needs of its customers.
The main constituent of these sorbents is lithium chloride aluminate. These types of sorbents typically operate optimally at higher temperatures. In some commercial operations worldwide, Vulcan understands that gas is used to heat up the brine prior to lithium extraction. In Vulcan’s case, the brine is naturally pre-heated from a hot geothermal reservoir, thereby reducing operating cost and removing the need for fossil fuels in the process, ultimately enabling a net zero carbon footprint for lithium production.
Vulcan has selected VULSORB as its first choice of sorbent for lithium extraction in its planned Phase 1 commercial development, with first commercial production of lithium targeted for Q4 2025. Vulcan continues to test other sorbents from commercial suppliers to provide further optionality, and for potential use in future phases of development.