Improved methodology for the measurement of vapor-liquid equilibria of binary mixtures with large boiling point differences via differential scanning calorimetry

• Methodology for high boiling point difference samples using DSC was expanded • Sample volume and heating rate optimized to improve boiling point accuracy • VLE data measured for the high boiling carvacrol–DMSO binary system The transition from petrochemical to bio-based processes introduces a multitude of novel products and the need for corresponding thermodynamic phase equilibrium data. Differential scanning calorimetry (DSC) offers a small-scale and fast method to determine solid-liquid as well as isobaric vapor-liquid equilibrium data in a wide temperature range. This study aims to extend the use of DSC to measure boiling point data of binary mixtures, focusing on systems with large boiling point differences. By adjusting sample volume and heating rate, the accuracy of measured boiling points for systems with high boiling point differences was improved. The measuring method was applied to a high boiling binary system consisting of carvacrol and dimethylsulfoxide and the experimental data was successfully correlated using the NRTL model. This work broadens the applicability of DSC for future thermodynamic investigations in vapor-liquid equilibrium studies, particularly for high boiling systems with large boiling point differences.