University of Kentucky Scientists Transform Massive Bourbon Distillery Waste Streams Into High-Performance Energy Storage Supercapacitors

University of Kentucky researchers convert bourbon "stillage" waste into carbon electrodes, creating supercapacitors that outperform current commercial devices.

By: AXL Media

Published: Mar 25, 2026, 5:16 AM EDT

Source: Information for this report was sourced from American Chemical Society

Converting Industrial Waste into High-Tech Hardware

The massive scale of American whiskey production has long generated a secondary challenge in the form of organic waste, with every barrel of bourbon resulting in up to ten barrels of a soggy grain residue known as stillage. While this byproduct is traditionally repurposed as low-value livestock feed, its high water content makes it expensive to process and transport. Researchers at the University of Kentucky, led by graduate student Josiel Barrios Cossio and chemist Marcelo Guzman, have identified a way to turn this logistical burden into a technological asset. By utilizing hydrothermal carbonization, the team has successfully transformed the soupy mash into sophisticated carbon materials suitable for high-performance energy storage electrodes.

The Chemistry of Hydrothermal Carbonization

The transformation process mimics a high-intensity pressure cooking environment to convert the wet stillage into a fine, versatile black powder. This method allows the scientists to utilize the high water content of the waste as a medium for the chemical reaction, rather than a hindrance that needs to be dried. Once the initial powder is formed, it is subjected to varying levels of heat and chemical treatment to produce two distinct types of carbon. Hard carbon is produced at 392 degrees Fahrenheit for use in lithium-ion absorption, while activated carbon is created at 1,472 degrees Fahrenheit using potassium hydroxide to create an extremely porous surface area capable of holding a massive electrical charge.

Breaking Barriers with Hybrid Energy Devices

The most significant breakthrough in the study involves the creation of hybrid lithium-ion supercapacitors, which occupy a strategic middle ground between the fast-discharge capabilities of traditional capacitors and the high-capacity storage of batteries. The Kentucky team achieved a rare feat by sourcing both the battery-type hard carbon electrode and the capacitor-type activated carbon electrode from the same agricultural waste stream. In laboratory tests, these bourbon-derived hybrid devices stored up to 25 times more energy per kilogram than conventional versions. This dual-electrode sourcing from a single waste product simplifies the manufacturing chain and proves the high value inherent in distillery byproducts.