Southwest Research Institute discovers source of "apple jelly" jet fuel contamination problem

Diesel Fuel News, Oct 28, 2002

A dark, gelatinous "apple jelly" material can form with U.S. Air Force JP8 100 jet fuel, which includes a diethylene glycol methyl ether (DiEGME) anti-icing additive. The additive mixes with water, forming a solvent. The solvent reacts with fuel storage system dirt, rust, fuel-line components, elastomers and even the water-absorbing fuel filters in some military fuel-handling systems, SwRI found.

The resulting "jelly" could be avoided by minimizing water contamination in bulk jet-fuel storage, and avoiding DiEGME additization until just before "clean" jet fuel is loaded onto wing tanks -- not always possible due to variable world-wide logistics for Air Force fuel. Other users of jet fuel (including those who blend kero-jet with diesel fuel, especially in winter) shouldn't be affected since DiEGME isn't normally used except in Air Force fuel, SwRI says.