Vapor pressure and vapor-liquid equilibrium data for eugenol/caryophyllene binary system at low pressures by experimental and predictive methods

The main objective of this study was to determine the vapor-liquid equilibrium of the binary mixture eugenol/caryophyllene at reduced pressures and to obtain pure compounds vapor pressure data in the same low-pressure condition. Isobaric vapor-liquid equilibrium (VLE) data have been measured in a Fischer ebulliometer at 5.0, 10.0, and 20.0 kPa. The vapor pressure of the pure compounds was determined by direct measurement of the equilibrium temperature at different pressures. The extended Antoine equation and the Clarke and Glew equation were fitted to the experimental data and compared with a predictive method. The thermodynamic consistency of the VLE experimental data was checked using the Redlich-Kister area test and the Van Ness point test. The binary interaction parameters of NRTL, Wilson, and UNIQUAC activity coefficient models were fitted from regression of experimental data. The average absolute deviation of the temperature (AAD(T)) and vapor-phase molar fraction (AAD(y)) are less than 0.22 K and 0.0119, respectively, proving a good adherence of the models for the calculation of the VLE system. The COSMO-SAC model was used to predict activity coefficients, compared with classic thermodynamic models, and was able to represent the azeotrope presented by the mixture. (C) 2022 Elsevier Ltd.

Automated summary

The main objective of this study was to determine the vapor-liquid equilibrium of the binary mixture eugenol/caryophyllene at reduced pressures and to obtain pure compounds vapor pressure data in the same low-pressure condition. Experimental data showed that the models used in this study were able to accurately calculate the temperature and vapor-phase molar fraction of the VLE system.