Jet fuel contamination testing for detection of Fatty Acid Methyl Ester (FAME Biodiesel).
Jet engine manufacturers agree jet fuel must contain less that 5 ppm of Fatty Acid Methyl Ester (FAME). Concerns around FAME contamination are documented in Bulletin No 26 from the Joint Inspection Group (JIG). Intertek determines the presence of FAME contamination in Jet Fuel by GC/MS analysis.
Intertek laboratories determine FAME contamination to less than 5 ppm levels. The requirement was incorporated in DEF STAN 91-91 and is expected to be added into the ASTM D1655 Jet Fuel Specification.
Jet fuel is often transported in common-carrier and multi-product pipeline and distribution systems. Shipping Biodiesel in multi-product pipelines may create a risk of cross-contamination of Jet Fuel with residual biodiesel components. The bio-component in biodiesel is a surface-active material, meaning FAME may adhere to pipe and tank walls as the biodiesel passes through, and then is released from the walls into the following product, which may be jet fuel.
Small amounts of diesel containing FAME may remain within distribution manifolds, tanks, vehicles, and pipes, increasing the risk of FAME traces getting into jet fuel transported through the same components. At high enough concentrations, FAME can impact the thermal stability of jet fuel, leading to coke deposits in the fuel system. FAME contamination can also impact the freezing point of jet fuel, resulting in fuel gelling. Such conditions can result in engine operability problems and possible engine flame-out.