The analysis of the gas turbine fuels by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy as applied to the composition explicit (or advanced) distillation curve method is reported. In order demonstrate the general applicability for such fuels, eight independent fuel samples were characterized: one sample of JP-5, one sample of JP-8, and six samples of Jet-A. Distillate fractions were obtained for each fuel by use of the advanced distillation curve (ADC) method. These fractions were analyzed by 1H and 13C NMR, along with the undistilled residue (i.e., the undistilled liquid remaining in the kettle after 90 vol % has been distilled), and the neat fuel. NMR spectroscopy is useful for the analysis of complex hydrocarbon mixtures because it provides the mole fractions of various classes of hydrocarbons, such as aromatics and linear alkanes, without the need to calibrate. NMR spectroscopy also gives ready access to other average properties for the components of each fuel sample, such as the extent and type of alkane branching. Such information is useful for the development of realistic fuel surrogates required for reliable thermophysical models. Finally, we compare the results obtained by NMR spectroscopy to previously reported GC-MS and GC-FID analyses of the same fuel samples.
Energy and Fuels
advanced distillation curve, gas turbine fuel, NMR.