According to the study, a major barrier to wider use of biodiesel fuel is the lack of a low-cost, high-quality source, or feedstock for producing the fuel. The concentration of oil in spent coffee grounds compares favorably with rapeseed, palm and soybean oil.
Growers produce more that 16 billion pounds of coffee around the world each year, says the study. The used grounds remaining from the production of espresso, cappuccino and regular coffee usually wind up in the trash or find use as a soil conditioner. Scientists in the study suggest that spent coffee grounds can potentially add 340 million gallons of biodiesel to the world’s fuel supply.