With continual technological progress in electric cars and mobile devices, the worldwide demand for lithium has rapidly outpaced the rate at which it can be recycled or mined. However, there may be a solution put forth by a University of Texas at Austin professor and his research team.
Benny Freeman, Professor at the McKetta Department of Chemical Engineering in the Cockrell School of Engineering, and his colleagues at the Monash University Department of Chemical Engineering and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia, have recently discovered a new, efficient method to extract lithium and other substances from water. The findings have been published in the February 9 issue of Science Advances.
The team’s method uses a metal-organic-framework membrane that imitates the filtering function, or “ion selectivity,” of biological cell membranes. The membrane process smoothly and efficiently splits metal ions, opening the door to ground-breaking technologies in the water and mining sectors and probable economic growth opportunities in Texas.
The Barnett and Eagle Ford shale formations in Texas have high quantities of lithium, and the produced wastewater formed by hydraulic fracturing in those areas contains high concentrations of lithium. Rather than discarding the produced water, the team’s membrane filter could extract the resulting lithium and put it to use in other sectors.
Produced water from shale gas fields in Texas is rich in lithium. Advanced separation materials concepts such as ours could potentially turn this waste stream into a resource recovery opportunity.
Professor Benny Freeman, McKetta Department of Chemical Engineering, Cockrell School of Engineering
Each well in the Barnett and Eagle Ford can produce up to 300,000 gallons of generated water per week. Applying their new process, Freeman and his team conservatively estimate that from just one week’s worth of produced water, sufficient lithium can be recovered to power 1.6 million smartphones or 200 electric cars.
Furthermore, the team’s process could assist with water desalination. In contrast to the current reverse-osmosis membranes responsible for over half of the world’s current water desalination capacity, the new membrane process dehydrates ions as they pass through the membrane channels and eliminates only select ions, instead of indiscriminately eliminating all ions. The result is a method that costs less and devours less energy than conventional approaches.
The team’s material functions on principles inspired by extremely effective biological cell membranes, whose mechanism of operation was revealed by Roderick MacKinnon and Peter Agre and was the subject of the 2003 Nobel Prize in chemistry.
The prospect of using metal-organic frameworks for sustainable water filtration is incredibly exciting from a public-good perspective while delivering a better way of extracting lithium ions to meet global demand could create new industries.
Anita Hill, Chief Scientist at CSIRO
The research received funding from the Australian Research Council, the Australian-American Fulbright Commission, the Commonwealth Scientific and Industrial Research Organization and the National Computational Infrastructure in Australia.