Characterization of Four Diesel Fuel Surrogates by the Advanced Distillation Curve Method

The development of surrogate fuels with measured and predicted thermophysical properties similar to their authentic refinery stream counterparts is critical for the development of alternative fuels and the optimization of engines to increase efficiency and decrease emissions. In this work, four diesel fuel surrogates, formulated according to a reliable and proven procedure, were characterized by the advanced distillation curve (ADC) method to determine the composition and enthalpy of combustion in various distillate volume fractions. Tracking the composition and enthalpy of distillate fractions provides valuable information for determining structure-property relationships and also provides the basis for the development of equations of state that can describe the thermodynamic properties of these complex or simplified mixtures. This comparison showed that the volatility characteristic of the four surrogates is quite similar not only to the target diesel fuel but also to a number of other prototype alternative diesel fuels. The number of components in the surrogates affected how closely their volatility profiles resembled diesel fuel, as might be expected. The surrogate labeled V0a, consisting of just four components, was the most dissimilar to the target diesel fuel with respect to the initial boiling point and volatility curve shape. This suggests that, although minimizing the number of components greatly eases modeling and formulation efforts, caution should be used to avoid oversimplifying the surrogate mixtures.