Summary:
UCLA researchers in the Department of Civil and Environmental Engineering have developed a novel, compaction-resistant reverse osmosis membrane for desalination under high pressures.
Background:
Access to safe drinking water is of utmost importance for everyone, and by 2025 half of the world’s population will live in areas where demand for clean water outpaces supply. Reverse osmosis is a popular method for treating water from nearly any source to produce ultra-pure potable water. Depending on the quality of source water, extensive treatment may be necessary to generate clean water. Abundant sources like brackish water and seawater have high salt contents, demanding membranes that can function under high pressures. Previous membranes fabricated for this application report thickness reductions of more than 20% and permeability reductions of up to 60% when used under industrially relevant pressures, indicating a clear and pressing need for robust reverse osmosis membranes capable of maximum performance under ultra-high pressures.
Innovation:
Researchers led by Professor Eric Hoek produced a novel, compaction-resistant thin film membrane (TFX) composed of thermoset polymers, meaning they are relatively inert to temperature changes and could therefore be used in high-temperature desalination. When TFX membranes were tested under a pressure of 200 bar, they maintained 85% to 90% of their low-pressure permeance compared to a conventional membrane which fell to only 55% permeance. TFX membranes also experienced less than 15% reduction in thickness while the conventional membranes were compacted by over 40%, potentially increasing membrane longevity. When tested for salt rejection performance, TFX achieved over 99% rejection at 60 bar and exceeded commercial membrane performance at 200 bar.
Potential Applications:
• Desalination
• High-pressure reverse osmosis
• High-temperature reverse osmosis
Advantages:
• 85% to 90% permeance up to 200 bar
• Less than 15% compaction up to 200 bar
• Salt rejection >99% at 60 bar
• Outperforms commercial membranes under high pressure
Development-To-Date:
Membranes have been fabricated and tested
Reference:
UCLA Case No. 2023-303
Lead Inventor:
Eric Hoek