Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

The complex nature of finished fuels makes definitive studies on composition and combustion properties very difficult and uncertain. This has led to the adoption of fuel surrogate mixtures in such studies. The development of a surrogate mixture is itself a nontrivial process, and a surrogate mixture is often developed specifically for a given purpose. Often, thermophysical property surrogate mixtures cannot be used for examination of combustion properties, and vice versa. Surrogates range in complexity from a single component to complex mixtures containing 20 or more components. A recent study on surrogate mixture development for diesel fuel used state-of-the-art techniques of 13C and 1H nuclear magnetic resonance (NMR) spectroscopy and the advanced distillation curve to characterize fuel composition and volatility, respectively. This work indicated the need for a multiply substituted, low cetane number, high molecular mass monocycloalkane surrogate mixture component. The addition of 1,3,5-triisopropylcyclohexane as a palette component was chosen to serve this need. Before this component can be used in any modeling or experimental effort, we first require some basic chemical and thermophysical properties. In this paper, we present chemical characterization results from gas chromatography with mass spectrometry, 13C NMR spectrometry, isothermal Kovats' retention indices at (150 to 225) deg C (on 5 % phenyl-95 %-dimethyl polysiloxane), and refractive indices at (20, 25, and 30) deg C. We also present ambient pressure thermophysical property measurements: density, speed of sound, and derived adiabatic compressibility from (5 to 70) deg C and kinematic viscosity from (20 to 100) deg C. These properties and characterization parameters are critical to the successful application of 1,3,5-triisopropylcyclohexane in experimental and modeling studies of surrogate diesel fuels.