The Use of Bio-Fuels as Additives and Extenders for Aviation Turbine Fuels

The use of biologically derived oils and fuels has received increasing visibility in recent years. A combination of fuel availability, refinery capacity and environmental responsibility has resulted in interest in their use in turbine engine fuels. Such a soy methyl ester (SME) is being evaluated as a possible extender and/or additive for aviation turbine fuel per ASTM D-1655. Laboratory testing indicates additive levels of up to 2% by volume can be used while still meeting ASTM D-1655. Engine testing performed at 20% blending levels have demonstrated potential fuel consumption improvements as well as reduction in NOx emissions. The final blend levels have not yet been determined. The use of SME even at low levels could provided performance benefits. Because of the oil nature of SME, a small addition could result in significant increases in lubricity. The use of the higher flashpoint SME could result in an upward shift in flashpoint with little or no effect to other physical properties. With increased visibility to work place considerations, the potential for “odor” abatement is also of interest.