As part of our research, we looked at the issue of fuel flammability in aircraft. We found there have been at least 26 documented fuel tank explosion accidents since 1959. Tell us how you became interested in the role of sulfur in the thermal stability of jet fuel. I became interested because fuel sulfur seems to be the cause of most deposit formation in the fuel systems, intake valves, and combustion chambers of engines. All hydrocarbon fuels, whether gasoline, diesel, or jet fuel, form engine deposits.
Fuels always contain some oxygen, which causes auto-oxidation.
In gasoline engines, deposits form on the injectors and valves. They gum things up. In jet engines, deposits develop because the heat exchangers and injectors are exposed to very high temperatures. Inlet air entering the gas turbine engine passes over the injector before the fuel is injected into the combustion chamber. The injectors become very hot and fuel temperatures reach nearly 500 F. Sulfur appears to be a major culprit in making deposits.