U.S. and Australian researchers have come up with a new process to extract lithium and other metals and minerals from water.
Professor Benny Freeman from the Cockrell School of Engineering at the University of Texas at Austin, along with colleagues at the Monash University and CSIRO, have devised a method to recycle lithium is which is being fast depleted a lot quicker than it can be mined or recycled – thanks to the advancement of mobile and EV technology.
The team’s technique uses a metal-organic-framework (MOF) membrane that mimics the filtering function, or ion selectivity, of biological cell membranes.
According to the researchers, the membrane process easily and efficiently separates metal ions, opening the door to revolutionary technologies in the water and mining industries.
The Barnett and Eagle Ford shale formations in Texas contain high amounts lithium, and the produced wastewater generated by hydraulic fracturing in those areas has high concentrations of lithium. Instead of discarding the produced water, the team’s membrane filter could extract the resulting lithium and put it to use in other industries.
“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,” Freeman said.
Each well in the Barnett and Eagle Ford can generate up to 300,000 gallons of produced water per week. Using their new process, Freeman and his team conservatively estimate that from just one week’s worth of produced water, enough lithium can be recovered to power 200 electric cars or 1.6 million smartphones.
The team’s process could also help with water desalination.
Unlike the existing reverse-osmosis membranes responsible for more than half of the world’s current water desalination capacity, the new membrane process dehydrates ions as they pass through the membrane channels and removes only select ions, rather than indiscriminately removing all ions.
The end result according to the researchers is a process that costs less and consumes less energy than conventional methods.
Image credits and content: CSIRO Blog/The University of Texas at Austin