Kinetics of deposit formation from hydrocarbons. III. Heterogeneous and homogeneous metal effects

The nature of metal surfaces (‘heterogeneous’ metals) and the presence of metal complexes (‘homogeneous’ metals) both markedly influence the rate of formation of deposits from hydrocarbon jet fuels at 200 to 500° F in the presence of oxygen. Copper surfaces and titanium alloy surfaces which contain vanadium were found to be particularly deleterious. The addition of 50 ppm metal using various metal acetylacetonates to the hydrocarbon fuel increased the rate of deposit formation by a factor of from 40 to 120 at 300° F. Copper acetylacetonate produced a higher rate of deposit formation than iron, nickel or cobalt acetylacetonates. The relative rate of deposit formation depended on the square‐root of both the vanadium content of the titanium alloys and the concentration of a ferric acetylacetonate in the fuel.