ANALYSIS OF MIDDLE DISTILLATE FUELS BY MIDBAND INFRARED-SPECTROSCOPY

A new analytical method based on infrared spectroscopy in the 4000-650 cm-1 wavenumber region has been developed that allows for rapid and r eliable measurement of several pertinent fuel properties simultaneousl y. The method may be automated and, by using ruggedized commercially a vailable Fourier transform infrared (FTIR) equipment, would be eminent ly suitable for commercial and military field applications. Preliminar y studies show that middle region infrared spectroscopic data may be c alibrated to determine those middle distillate fuel properties that ar e due to chemical structural features that give rise to active infrare d resonance bands. The measured fuel property values must relate linea rly to spectral intensities; i.e., they must obey Beer's law. In this study, the initially selected fuel properties were aromatic hydrocarbo n content, carbon-to-hydrogen ratio, heat of combustion, cetane index, viscosity, and density. Other properties such as cloud point, pour po int, octane number, cetane number, etc. are also expected to be succes sfully modeled. Usefulness of the method will be extended for the anal ysis of other fossil, as well as alternate fuels.