Bourbon Waste Turned Into High-Performance Supercapacitor Electrodes by Kentucky Researchers
Researchers at the University of Kentucky have demonstrated that spent grain from bourbon distilleries can be converted into high-performance supercapacitor electrodes that match or exceed commercial devices, potentially turning a costly waste disposal problem into a profitable energy storage material source.
The Problem
Kentucky produces over 95% of all bourbon whiskey. For each barrel, the industry produces 6-10 times as much 'stillage' (spent grain and water slurry). Drying this waste for transport to farmers is a major burden on distilleries, requiring significant time, space, or expensive heating.
The Solution
The researchers use hydrothermal carbonization to directly convert wet stillage into fine carbon powder, which is then processed into electrode materials for supercapacitors and batteries. The resulting supercapacitors match or exceed commercial energy density, and hybrid lithium-ion supercapacitors can store up to 25 times as much energy as conventional designs.
The Impact
- Distilleries could turn waste into profit
- More renewable biomass source for energy storage materials
- Growing demand from EV and renewable energy industries
- Reduces waste disposal costs and environmental impact
One distillery was so eager to get rid of its stillage that when the researcher asked for one gallon, they replied: 'I would prefer that you take 10,000 gallons and get rid of the stillage from that day.'
Source: IEEE Spectrum / American Chemical Society