Coffee beans are usually ground and extracted for drinking, and the extracted coffee grounds are often discarded or poured into ashtrays. But a study by the University of Nevada found that coffee grounds are relatively easy to convert into biofuels of 10% of their weight and 15% of their weight as car fuel. And coffee grounds fuel does not produce a pungent smell when burned in the engine-only a hint of coffee. After the fuel oil has been squeezed out, the remaining coffee grounds can still be used as fertilizer.
