Color Change/Sediment Formation in Marine Diesel Fuels

The cause of instability in marine diesel fuels was investigated by aging several fuels. Aged and unaged fuel samples were chromatographically separated into acid, base, and neutral fractions, and the fractions analyzed in detail to obtain a clearer understanding of fuel changes induced by aging as well as probable mechanism for color change and sediment formation. Sediments generated by aging fuel samples were analyzed by high-resolution, low-voltage mass spectroscopy. Our work suggests that oxidation of neutral components present in fuel to polar intermediates may be a major pathway for sediment formation and darkening of diesel fuels.