Every liter of ethanol produced results in about 10 to 18 liters of vinasse as a waste product. Considering the size of the alcohol producing industry this is a considerable amount of waste. Despite its use as fertilizer or animal feed, Shi et al. have now shown that vinasse is also a promising precursor material for advanced energy storage devices.
The Chinese researchers reported their findings in a recent Advanced Sustainable Systems article. They showed that conversion of sorghum vinasse via a simple process leads to a highly porous carbon material with a unique microstructure. The structure contains abundant graphene nanoplatelets, which boost specific capacitance and electrical conductivity. Additionally, ball milling during the process significantly increases the wettability of the surface. These features qualify this type of carbon as an exceptional electrode material for supercapacitors with high power density.