Fuel Sediment Analysis by ESCA.
NAVAL RESEARCH LAB WASHINGTON DC
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The technique of x-ray photoelectron spectroscopy XPS, ESCA was applied to the analysis of sediments which are formed in fuel and which degrade fuel storage stability. Samples studied included sediments formed in a Navy Paraho Shale II DFM fuel by doping fuel samples with 2,5-dimethylpyrrole and stressing the mixtures for periods of 4 to 28 days at 80 C. Several naturally occurring sediments were also investigated. Carbon, oxygen, nitrogen, and sulfur spectra were obtained where applicable. Atomic ratio results show indications of changes in sediment composition over time, and indicate that the composition of various fractions associated with a given sediment may differ. Comparisons of the ESCA spectra of induced vs natural sediments indicated some differences particularly in the nitrogen spectra. Some solubility studies were performed to determine effects of stress time on solubility. The sediment fractions remaining after solvent treatment were also subjected to analysis by ESCA. A comparison of their spectra with the sediment spectra taken before solvent treatment indicated differences in the atom ratios. Structural feature comparisons were inconclusive.
- *X RAY PHOTOELECTRON SPECTROSCOPY
- *DIESEL FUELS
- METHYL RADICALS
- STRUCTURAL PROPERTIES
- MOLECULAR WEIGHT
- CHEMICAL ANALYSIS
- TRACE ELEMENTS
- GUM STOCKS
- Atomic and Molecular Physics and Spectroscopy
- Nuclear Physics and Elementary Particle Physics