Soyoil is Safe Additive in Aviation Fuel

WASHINGTON - Jul 9/01 - STAT -- Soybean oil derivatives can be safely added to noncommercial jet fuel used in military aircraft, according to a recent study by the USDA's Agricultural Research Service.

In laboratory studies, ARS chemical engineer Robert O. Dunn added small amounts of methyl soyate (SME)--esters from fatty acids of soybean oil--with noncommercial jet fuel (JP-8). Dunn has developed a three-step winterization process for biodiesel fuel that involves mixing in additives, chilling the fuel and filtering out solids.

In previous tests, Dunn produced biodiesel fuels capable of starting diesel engines at temperatures as low as 5 degrees Fahrenheit, making them comparable to petroleum- based diesel fuels. Using biodiesel fuel blends that haven’t been winterized could limit aircraft’s ability to fly at high altitudes, where cold temperatures can cause crystal formation, blocking fuel filters and plugging fuel lines.

The most promising aspect of this work: Winterized SME did not form solid particles when exposed to a range of slightly below zero to -52 degrees F in the laboratory.

But eventually even winterized SME blends will form solid particles when temperature is low enough. The research continues to expand the lower limits of temperature so that winterized, blended biodiesel fuels can function safely in military aircraft. The impetus behind the research comes from the Clean Air Act and its more recent amendments that call for a reduction of harmful emissions from commercial and military aircraft.

Biodiesel is a renewable commodity and produced domestically. The U.S. currently imports half its oil at a cost of $60 billion annually. Biodiesel has another advantage -- is nonflammable, making it relatively safe to store and handle and environmentally innocuous because it’s biodegradable.

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