Coffee, that deliciously-bitter black beverage that gives us an all-important caffeine boost in the morning, is hardly what you think of when it comes to powering your espresso machine, but now scientists have found a way to trap energy in your used coffee grounds and use them as fuel storage.
In apaperpublished in the journal Nanotechnology, scientists have discovered a simple process that captures and stores methane, which is not only a useful source of power but also one of the most powerful greenhouse gasses, trapping 25 times more heat in the atmosphere than carbon dioxide. Once stored, the methane can be used to produce heat, electricity and fuel – a much cleaner alternative to fossil fuels.
Christian Kemp, from Pohang University of Science and Technology in South Korea, found inspiration over a cup of coffee, "We were sitting around drinking coffee and looked at the coffee grounds and thought 'I wonder if we can use this for methane storage?'" (Clearly this is the sort of thing scientists think about over breakfast).
Instead of deciding to go with one of the many otheruses for spent coffee beans, researchers from the Ulsan National Institute of Science and Technology in South Korea managed to produce the stable carbon capture material in less than a day - a fraction of the time it normally takes – by soaking the waste coffee grounds in potassium hydroxide and heating it in a furnace to 700-900°C.
"The big thing is we are decreasing the fabrication time and we are using cheap materials," explains Kemp. "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."
It looks like coffee is more useful than we first thought, not that we needed another reason to keep drinking it.