Heat capacity measurements of petroleum fuels by modulated DSC

Abstract

In this work, the usefulness of modulated DSC (MDSC) for measuring the heat capacity of commercial hydrocarbon fuels is illustrated. Specifically, the reliability of the method is outlined by testing five liquid fuels of diverse composition and origin over a temperature range between − 70°C and 70°C. The experiments were carried out using a DSC 2910 module from TA Instruments Inc., upgraded with the MDSC option. The samples were exposed to a cyclic heating profile which was generated by a linear heating rate of 2°C min −1 while simultaneously superimposing a sinusoidally varying time-temperature wave with an amplitude of ± 0.5°C and a period of 100 s. On the basis of these measurements, MDSC proved to be a valuable technique with which to measure directly the heat capacity of hydrocarbon fuels. Moreover, the ability of MDSC to measure heat capacity with great accuracy and precision offers a powerful approach for studying the effects of compositional differences on heat capacity.