Colorado's myriad craft breweries may soon generate a different sort of buzz. A team of engineers and researchers with the University of Colorado at Boulder have found a way to turn brewery wastewater into battery electrodes, as reported by Science Daily.
So how does it work? Beer takes a lot of water to produce, and the resulting sugar-rich wastewater can't be dumped just anywhere; it must be thoroughly filtered and treated before it reaches sewer systems.
Tyler Huggins, the study's lead author and a student in the Department of Civil, Environmental and Architectural Engineering, said "Breweries use about seven barrels of water for every barrel of beer produced, and they can't just dump it into the sewer because it requires extra filtration."
With that much water going into just one gallon of beer - and hundreds of millions of gallons of beer produced in Colorado each year - wastewater treatment costs add up. Enter neurospora crassa.
A fast-growing filamentous fungus (say that three times fast), Neurospora crassa just loves to feast on the yeasty, sugary byproducts of beer brewing. As it feeds, it grows. "The wastewater is ideal for our fungus to flourish in, so we are happy to take it," Huggins said. Once it reaches the right size, the fungus is pyrolyzed ("decomposed through heating to a high temperature" - sorry, neurospora crassa) to form a carbon electrode material that's a key component in lithium-ion batteries.
"This could be game-changing," CU researcher and co-author Justin Whiteley said in an interview. "We're looking to replace the unsustainable materials that are in our batteries right now - mainly being graphite. Graphite is mined in the ground, mostly in China."
The process, called biomass, converts biological material into carbon-based battery electrodes. However, since biomass traditionally relies on plant matter like timber, raw material is usually expensive and limited in supply.
What's not in short supply, though, is the beer that flows freely from the Centennial State - and its byproducts, so the authors partnered with none other than Boulder's own Avery Brewing Co., which had plenty to spare.
According to a press release from CU Boulder, "If the process were applied on a large scale, breweries could potentially reduce their municipal wastewater costs significantly while manufacturers would gain access to a cost-effective incubating medium for advanced battery technology components."
In fact, Huggins and Whiteley have already filed a patent on the process, and are currently in the process of creating a company, called Emergy, to commercialize it. That's a win-win: brewers spend less on wastewater treatment, and manufacturers are able to create among the most efficient, renewable, natural-derived lithium-ion battery electrodes known to date.
The study was originally published in Applied Materials and Interfaces.