LONDON – New research from the University of Bath suggests waste coffee grounds could be a ‘‘sustainable fuel source’’ for powering vehicles.
The study found that different varieties of coffee, including Robusta and Arabica, have reasonably standard composition and relevant physical properties of fuel, suggesting that all coffee waste could be a “viable” way of producing biodiesel.
Waste produced from the average coffee shop – around 10 kilograms per day – was found to produce around two litres of biofuel.
Chris Chuck, Whorrod research fellow at the university, said that around eight million tonnes of coffee are produced globally each year, and ground waste coffee contains up to 20 per cent oil per unit weight.
This oil also has similar properties to current feedstocks used to make biofuels. But, while those are cultivated specifically to produce fuel, spent coffee grounds are waste, and there’s a real potential to produce a truly sustainable second-generation biofuel using these, he added.
Chuck added that coffee biodiesel would be a minor part of the energy mix but could be produced on a small scale by coffee shop chains to fuel vehicles used for deliveries.
The same delivery vehicles could be used to collect waste coffee grounds and take them to a central biodiesel production facility to be processed.
Oil can be extracted from coffee grounds by soaking them in an organic solvent, before using a process called transesterification to transform them into biodiesel.
