(258c) Circular Process Design for Zero-Carbon Lithium Recovery from Geothermal Brine

Lithium (Li)-ion batteries play a pivotal role in enabling efficient energy storage for renewable energy integration and the electrification of the transportation sector [1]. With electric vehicle demand projected to reach 46.8 million units by 2030, the demand for lithium—the essential component of Li-ion battery systems —is anticipated to reach 3.3 million metric tons of lithium carbonate (Li₂CO₃) equivalent [2]. This surge is already causing supply chain vulnerabilities, forcing countries like the United States to actively pursue unconventional domestic lithium sources, such as geothermal brine [3,4]. Geothermal resources offer sustainable energy production with unique benefits over other alternatives, as the brine serves a dual purpose by facilitating both power generation and lithium extraction prior to reinjection into reservoirs. [1,5-7].

We present an integrated process design for processing 2000 mt/h of Salton Sea geothermal brine for power generation alongside Li₂CO₃ extraction. The process is modeled and simulated using SuperPro Designer V.14.1 and Python 3.10.5. Our approach incorporates circular economy concepts by processing waste streams through a modified Solvay-type process where CO₂ is captured and converted into the main precipitating agent (Na₂CO₃) used for metal ion removal. This creates a closed-loop system that reduces both chemical reagent consumption and environmental impact. Furthermore, we conduct techno-economic analysis (TEA) and life cycle assessment (LCA) to quantify the economic viability and environmental impacts of the process. The results show that our design generates up to 70 MW of power and approximately 25,000 metric tons of battery-grade Li₂CO₃ annually, meeting industrial-scale production requirements [2]. Finally, we identify optimal temperature ranges for crystallization and washing processes across various NaCl concentrations in the brine that consistently yield battery-grade Li₂CO₃ with 99.5wt.% purity. This comprehensive process maximizes resource use while reducing environmental impact, catering to both energy and material requirements for sustainability.

1- Schenker, Vanessa, Peter Bayer, Christopher Oberschelp, and Stephan Pfister. "Is lithium from geothermal brines the sustainable solution for Li-ion batteries?." Renewable and Sustainable Energy Reviews 199 (2024): 114456.

2- Nikkhah, Hasan, Andrea Di Maria, Giuseppe Granata, and Burcu Beykal. "Sustainable process design for lithium recovery from geothermal brines using chemical precipitation." Resources, Conservation and Recycling 212 (2025): 107980.

3- Srinivas, Seethamraju, Daniel Eisenberg, Navid Seifkar, Paolo Leoni, Marco Paci, and Randall P. Field. "Simulation-based study of a novel integration: geothermal–biomass power plant." Energy & fuels 28, no. 12 (2014): 7632-7642.

4- Li, Jingyi, Raphael Ricardo Zepon Tarpani, Laurence Stamford, and Alejandro Gallego-Schmid. "Life cycle sustainability assessment and circularity of geothermal power plants." Sustainable Production and Consumption 35 (2023): 141-156.

5- Parikhani, Towhid, Mostafa Delpisheh, Maghsoud Abdollahi Haghghi, Shahriyar Ghazanfari Holagh, and Hassan Athari. "Performance enhancement and multi-objective optimization of a double-flash binary geothermal power plant." Energy Nexus 2 (2021): 100012.

6- Nikkhah, Hasan, Deniz Ipekçi, Wenjun Xiang, Zachary Stoll, Pei Xu, Baikun Li, Jeffrey R. McCutcheon, and Burcu Beykal. "Challenges and opportunities of recovering lithium from seawater, produced water, geothermal brines, and salt lakes using conventional and emerging technologies." Chemical Engineering Journal (2024): 155349.