Deposition of Carbonaceous Solids on Different Substrates from Thermal Stressing of JP-8 and Jet A Fuels

Abstract

Carbon deposition from jet fuel on metal surfaces will create problems for the operation of future aircraft. Two jet fuel samples (Jet A and JP-8) were heated in a glass-lined flow reactor in the presence of metal and nonmetal substrates placed in the fuel path. The solid deposits collected on the substrates were examined using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and by temperature-programmed oxidation (TPO). The nature and amount of carbonaceous deposits from the thermal decomposition of jet fuel were determined to be dependent on the substrate properties and jet fuel composition. In particular, the catalysis of carbon deposition by active metals was evident in deposits obtained on singlemetal or metal-alloy substrates. Jet A fuel produced much-smaller quantities of carbonaceous solids on active metal substrates than JP-8 fuel did. This variance is attributed to the differences in hydrocarbon and sulfur compound composition of the two fuels.

Comparison of Vibrations and Emissions of Conventional Jet Fuel with Stressed 100% SPK and Fully Formulated Synthetic Jet Fuel

“…Therefore, aviation fuel is subject to thermal stress in the flow path between the aircraft fuel tanks and the combustion chamber. High thermal loads can lead to temperatures as high as 500 °C on metallic surfaces in the fuel delivery system of advanced aircraft [17,18]. This heat leads to the formation of insoluble deposits which can plug the narrow passageways found in fuel systems and in extreme cases, lead to component failure.…”

Thermal stability and decomposition of diesel fuel under subcritical and supercritical conditions

“…It was also reported that stainless steel tubes formed more deposits than aluminum tubes [16] probably due to the catalytic behavior of iron and iron-based alloys during carbon oxidation [33].…”

“…It has been suggested that the nature and amount of solid deposition from the thermal decomposition of jet fuel were dependent on the substrate properties and jet fuel composition [33]. It was also reported that stainless steel tubes formed more deposits than aluminum tubes [16] probably due to the catalytic behavior of iron and iron-based alloys during carbon oxidation [33].…”

Catalytic cracking of RP-3 jet fuel over wall-coated Pt/ZrO2–TiO2–Al2O3 catalysts with different Al2O3 ratios

“…The alkene selectivities of Cat3, Cat4 at 650 • C are almost equals to 700 • C, and they have a sharp decrease at 750 • C. The addition of Cat3, Cat4 not only enhanced the rates of cracking reaction, but also improved the alkene selectivity of cracking reaction based on the increasing of the probability of cracking reaction with the mechanism of carbenium ions. The unstable carbenium ions are easy to occur the ␤-scission to generate alkenes [18,19].…”