Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Differential Scanning Calorimetry (d.s.c.) was used to determine the vapor pressure of the following ethyl esters: ethyl laurate, ethyl myristate, ethyl palmitate, ethyl stearate, ethyl oleate and ethyl linoleate in the range from 1.33 to 9.33 kPa. These esters are the major constituents of the biodiesel obtained from the transesterification of some vegetable oils with ethanol. Samples of 2 to 5 mg were used in the analysis, with a heating rate of 25 C /min and a pinhole with a diameter of 0.25 mm. The results showed that Differential Scanning Calorimetry was a suitable technique for measuring the vapor pressure of organic compounds like fatty esters. The constants of the Antoine equation were determined from the experimental data and the validity of this equation in representing the vapor pressure and vaporization enthalpy of the compounds under study was examined.