Biofuels could be a “game changer” for both military and commercial aviation, says Assistant Secretary of the Air Force Terry Yonkers, because they’re proving to have advantages over petroleum-based jet fuels that go beyond the environment.

Biofuels are produced from plant feedstocks or organic wastes. Public and private research has been focusing on production from non-food sources like algae, camelina, and jatropha, and on sustainable and economic ways to cultivate them.

Fischer-Tropsch fuels are derived from mixtures of coal, natural gas and/or biomass. This synthetic fuel process was developed in Germany in World War II, and adapting it to use biomass feedstocks has been a focus of research by the \US Departments of Energy and Defense.

Easy on the Environment and the Wallet

Burning biofuels is considered neutral for greenhouse gases because they release only carbon dioxide the plants absorbed while growing.

Both fuels can be blended with petroleum-based feedstocks, or burned alone if engines are adapted to them. Both the Defense Department and commercial airlines have been testing out various blends to make sure they perform at least as well as conventional fuels in real flight conditions – so far with success in both sectors.

Speaking to the Joint US Army/US Air Force Renewable Energy Industry Day in Arlington, VA, June 12, Yonkers said the Air Force is working toward certifying all of its jets to fly on biofuels and Fischer-Tropsch fuels.

Both are made from domestic feedstocks rather than imported sources, and an original goal was to add security to the military’s fuel supply.

But the testing has found unexpected benefits, he said. “Our tests show that these fuels burn cleaner and cooler.”

it makes good business sense to do it.” – Yonkers

Lower burn temperatures in particular make a substantial difference in engine materials fatigue, and consequently engine life. Testing indicates “we can get 10 times as many hours on drop-in biofuels as on conventional fuels,” Yonkers said.

In addition, biofuels have less mass than fossil-based fuels, allowing longer flights for the same weight, he said.

Check back shortly with Breaking Energy for additional coverage from the Joint US Army/US Air Force Renewable Energy Industry Day.

For commercial aviation, where aircraft weight is a key component of airline economics, that could make biofuels preferable to conventional jet fuel.

The Air Force spent $8.3 billion on aviation fuel in fiscal 2011, a cost that went up $1.5 billion from the previous fiscal year as world oil markets rose.

Yonkers said that illustrates that the Air Force is pursuing biofuels, and renewables on its land installations, “because it makes good business sense to do it.”