Making useful products out of old coffee grounds is pretty cool, but using them to save the planet is an even more exciting idea. Researchers at Ulsan National Institute of Science and Technology (UNIST) in South Korea are the geniuses behind the new carbon cleaning material, which is created by steeping used coffee grounds in a potassium hydroxide solution and then heating the mixture to 65 °C (149 °F). They dry out that material and then use an argon-atmospheric furnace to super-heat it, which activates its carbon-capturing capabilities. The whole process takes less than a day and, because used coffee grounds are insanely cheap, it’s a pretty cost-effective approach to a really big problem.
Cleaning carbon emissions from the atmosphere is a key challenge for modern researchers, and this coffee cum carbon capture capable creation – which is intended specifically to remove methane from the air – could be a real game changer. Although the research team doesn’t quite understand how it works, they are clear on the fact that it does. Adding sodium hydroxide makes it work even better. “It seems when we add the sodium hydroxide to form the activated carbon it absorbs everything,” says Christian Kemp, an original researcher on the work at UNIST and now a member of the Pohang University of Science and Technology faculty. “We were able to take away one step in the normal activation process – the filtering and washing – because the coffee is such a brilliant absorbent.”