CALCULATION OF JET AND DIESEL FUEL PROPERTIES USING C-13 NMR-SPECTROSCOPY

Simple linear relationships between properties and composition have been developed for a range of 51 jet fuels and 48 diesel fuels. Composition has been defined with the use of 13C NMR data alone and is expressed in terms of the fraction of aromatic carbon (Car) and the fraction of n-alkyl carbon (Cn). Relationships of the form P = b1Car + b2Cn + c, where P is the property value, Car and Cn are measured from quantitative 13C NMR spectra, and coefficients bl, b2, and c have been determined by multiple linear regression, have proven effective. For jet fuels (190-230 °C), properties investigated include smoke point, aromatics content, hydrogen content, heat of combustion, freezing point, and specific gravity. For diesel fuels (230-320 °C), properties investigated include pour point, cloud point, hydrogen content, aniline point, specific gravity, diesel index, and cetane index. It has been found that the above model is as effective as previous, more complex models based on HPLC + NMR or HPLC + GC data. © 1990, American Chemical Society. All rights reserved.