"NASA recently performed emissions testing on alternative, renewable fuels for a greener and less petroleum-dependent future. The search for alternative fuels is driven by environmental concerns as well as a desire for reduced reliance on foreign sources.
A team at NASA's Dryden Flight Research Center in California tested renewable biofuel made from chicken and beef tallow in one of the four engines of a DC-8 airplane.
The airplane remained on the ground during the test, known as the Alternative Aviation Fuels Experiment, or AAFEX, while aeronautics researchers measured the fuel's performance in the engines and examined the engine exhaust for chemicals and contamination that could contribute to air pollution. The test results seem to support the idea that biofuels for jet engines are indeed cleaner-burning, and release fewer pollutants into the air."
Full article:
NASA - Chicken Fat Fuel Emissions Look Cleaner, Greener