A dual membrane-adsorption evaporator for solar-powered lithium extraction from complex brines

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Growing demand for lithium necessitates efficient extraction methods.
• Current lithium extraction from brines faces challenges with selectivity and efficiency.
• Need for sustainable and energy-efficient technologies for lithium recovery.

Purpose of the Study:

• To develop and demonstrate a solar-powered system for effective lithium extraction from brines.
• To enhance lithium-to-magnesium selectivity and water evaporation flux using integrated technologies.
• To assess the long-term stability and applicability of the system in various brine compositions.

Main Methods:

• Synthesis of a three-dimensional adsorptive evaporator coated with lithium manganese oxide.
• Integration of an osmotic membrane with the evaporator to improve selectivity and prevent scaling.
• Utilizing solar energy, osmosis, and capillary force for autonomous operation.
• Testing the system with simulated brine solutions of varied chemistries.

Main Results:

• Achieved over 10-fold increase in lithium to magnesium selectivity (>40).
• Demonstrated high lithium to calcium selectivity and long-term operational stability.
• Maintained high and consistent evaporation rates across different brine solutions.
• The system operates without external energy input, driven by natural forces.

Conclusions:

• The coupled solar evaporation, adsorption, and membrane technology offers an efficient pathway for lithium extraction from brines.
• The developed system shows high selectivity for lithium over competing divalent cations.
• This technology is robust, scalable, and applicable to diverse global brine resources for sustainable lithium supply.