Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

This study is aimed to extend an application of the differential scanning calorimeter (DSC) based vaporpressure method to evaluate vaporization of a target substance from a complex matrix that exhibits sev-eral times lower vapor pressure. The experiments involved preparing mixtures of known composition andmeasuring their vapor pressure by a DSC based vapor pressure method (following ASTM 1785 guidelines).The vapor pressure of two types of associating binary systems were examined: (1) a narrow boilingrange oil fraction (or distillation cut) mixed with a pure compound (nicotine or 2-tert-butylphenol); (2)a mixture of two narrow boiling range oil fractions. Emphasis was placed on 50:50 mol% mixtures. Toevaluate deviation from ideality, the total vapor pressure curves measured were compared to valuescalculated from Raoult s law. Narrow boiling range oil fractions (distillation cuts) were treated as singlepseudocomponents in these calculations. The vapor pressure curves obtained suggest that the DSC basedvapor pressure method is a useful tool for characterizing these kinds of multicomponent systems. Theresults presented can be viewed as a preliminary indication of the extent of ideality in systems containing synthetic crude oil from Kukersite oil shale, which is rich in alkyl-phenolic moieties.