Sustainable process design for lithium recovery from geothermal brines using chemical precipitation
Hasan Nikkhah, Andrea Di Maria, Giuseppe Granata, Burcu Beykal
Abstract
Lithium demand is surging, necessitating efficient extraction methods. Geothermal brines offer a promising alternative feedstock, yet comprehensive systems-level analyses are lacking. We developed an industrial process model for a plant processing 2000 ton/h geothermal brine using chemical precipitation to produce lithium carbonate, coupled with techno-economic and life cycle assessments to evaluate process economics and environmental impacts. A novel recycling process for on-site reuse of precipitating agents is also proposed, increasing total investment cost by 23% while reducing CO 2 emissions by nearly 50% without extending the payback period. Additionally, we investigated the impact of feedstock concentration and water costs on process economics. Our findings show that low-concentration lithium brines (less than 200 mg/L) are economically viable only at high lithium carbonate selling prices. This study highlights the potential of geothermal brines as a sustainable lithium source and the benefits of integrating recycling processes to mitigate environmental concerns. • This work focuses on the critical need to extract lithium sustainably from geothermal brines. • We have found an innovative procedure that effectively decreases carbon dioxide emissions by 50%. • Our idea incorporates an on-site recycling technique, effectively reducing operational expenses. • Water costs play an important role in the process’s economic viability for low lithium concentration brine.