Bourbon Waste Becomes Powerful Energy Storage Device

Every barrel of bourbon creates up to 10 barrels of watery waste grain, and chemists just figured out how to turn that problem into powerful energy storage.

Graduate student Josiel Barrios Cossio at the University of Kentucky was shocked when he learned about the massive waste problem facing bourbon distilleries. The leftover mash, called stillage, is sometimes sold as livestock feed or fertilizer, but it's expensive to dry and hard to move when wet.

Cossio and his advisor Marcelo Guzman wondered if they could transform the waste into something more valuable. They collected samples from local distilleries, whose owners were eager to help find a solution.

The team used a pressure cooking technique called hydrothermal carbonization to turn the watery stillage into black powder. Then they heated that powder in a furnace to create two forms of carbon: hard carbon similar to graphite and activated carbon infused with potassium hydroxide.

Both types of carbon work perfectly as electrodes in energy storage devices called supercapacitors. The researchers sandwiched a liquid electrolyte between two activated carbon electrodes to create their first prototype.

The results exceeded expectations. Their double-layer capacitors stored up to 48 watts per kilogram, matching commercial devices already on the market.

Then they built a hybrid version with one activated carbon electrode and one hard carbon electrode, adding lithium ions to both. This second design stored 25 times more energy per kilogram than conventional supercapacitors.

The Ripple Effect

This breakthrough could help bourbon distilleries across Kentucky and beyond turn their biggest waste problem into a revenue stream. Instead of paying to dispose of stillage or selling it cheap as animal feed, distilleries could supply the clean energy industry with raw materials for next-generation batteries.

The timing couldn't be better as the world searches for sustainable energy storage solutions. Bourbon production has boomed in recent decades, with the industry now worth billions and growing every year.

The research team plans to scale up their supercapacitors and study whether the process makes economic sense for distilleries. They're also analyzing the overall environmental impact to ensure the solution is truly sustainable.

Local distillery owners remain enthusiastic partners in the research, seeing potential for an industry known for tradition to lead in green technology innovation.

From waste to watts, bourbon is proving it has more to offer than just a smooth drink.