According to Green Car Reports, coffee ground can be turned into biofuel without the use of algae, although this way, the process is slightly more difficult.

Researchers at Aston University in the UK were able to grow algae in coffee ground, both as the soil base and the nutrient for the organism.

By playing around with this process, they discovered that ground coffee grown algae can make oils that can be turned into biofuels and these have a minimal carbon footprint, while delivering good engine performance.

While internal combustion engines are here to stay for the next few years, these new biofuels can ensure that fossil-powered cars have a lower environmental footprint until we will be able to turn to a clean alternative for good.

The diesel engines have a slight advantage here, because so far, gasoline alternatives, such as corn-derived ethanol, aren't as eco-friendly and are actually more polluting than regular petrol.