The carbon saving for a litre of renewable fuel can be very large indeed, because extracting and refining fossil fuels uses a lot more energy than just burning the fuel. Waste-derived biodiesel has a carbon intensity of 437 grams CO2 per litre, compared with 3,128 grams per liter for fossil diesel. So the carbon saving is 2,691 grams CO2 eq per litre. Green Fuels’ equipment has saved more than 6.5 million tonnes of CO2 eq since 2003.
As fuels are burned in an engine, they produce more than just carbon dioxide. There is good evidence in the scientific literature that renewable fuels can produce lower levels of particulate pollution than fossil fuels – seen in cleaner-burning diesel engines and in less contrail formation from jet aircraft.