Now it’s no secret that I drink a lot of coffee. I mean a lot of coffee. I don’t even want to think how many kilos of used coffee grounds I’ve thrown into the bin or flushed down the drain over the years. Well it looks like all of those grounds could have been more useful than I realised!
A team at the University of Nevada have been working on turning used coffee grounds into biodiesel. Given how many coffee grounds are thrown away across the world on a daily basis, just think about how wasteful that is, if all of those grounds could be used. What’s more, wouldn’t busy city streets be a lot nicer if the exhaust fumes smelled of coffee! It’s true that in Brazil, work has been done to turn sub-standard coffee beans into biofuel, which is a similar process. As far as I can tell though, no one’s ever tried doing this with used coffee grounds before.
It’s pretty simple, really. Despite the oils that get extracted into your daily dark and caffeinated beverage, quite a few are left behind in the grounds. You can then extract these oils and transesterify them to make biodiesel. It works in exactly the same way as other biodiesel production, except we don’t need to monopolise third world farmland to make it. We’re making it out of something we’re already throwing away.