Brewery wastewater turned into energy storage cells

New York: Researchers have developed a manufacturing process that uses a biological organism cultivated in brewery wastewater to create the carbon-based materials needed to make energy storage cells.

The scientists believe that this unique pairing of breweries and batteries could set up a win-win opportunity by reducing expensive wastewater treatment costs for beer makers while providing manufacturers with a more cost-effective means of creating renewable, naturally-derived fuel cell technologies.

"Breweries use about seven barrels of water for every barrel of beer produced," said lead author of the study Tyler Huggins from the University of Colorado Boulder in the US.

"And they can't just dump it into the sewer because it requires extra filtration," Huggins noted.

The process of converting biological materials, or biomass, such as timber into carbon-based battery electrodes is currently used in some energy industry sectors.

But naturally-occurring biomass is inherently limited by its short supply, impact during extraction and intrinsic chemical makeup, rendering it expensive and difficult to optimise.

The researchers in this study utilised the efficiency of biological systems to produce sophisticated structures and unique chemistries by cultivating a fast-growing fungus, Neurospora crassa, in the sugar-rich wastewater produced by breweries.

"The wastewater is ideal for our fungus to flourish in, so we are happy to take it," Huggins explained.

By cultivating their feedstock in wastewater, the researchers were able to better dictate the fungus's chemical and physical processes from the start.

They thereby created one of the most efficient naturally-derived lithium-ion battery electrodes known to date while cleaning the wastewater in the process.

If the process, described in the American Chemical Society journal Applied Materials & Interfaces, 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.

Huggins and study co-author Justin Whiteley, also of the University of Colorado Boulder, have filed a patent on the process and created Emergy, a Boulder-based company aimed at commercialising the technology.