Measurement and correlation of isothermal vapor-liquid equilibrium for (−)-β-caryophyllene + p-cymene with dehydroabietic acid at 313.15, 323.15, and 333.15K

Abstract

BackgroundBoth rosin and turpentine are extremely abundant and renewable resources in nature. p-Cymene and (−)-β-caryophyllene are components of turpentine and dehydroabietic acid is a component of rosin. The determination of their vapor-liquid equilibrium data can provide more complete basic data for the separation and purification of rosin and turpentine systems. MethodsThe isothermal vapor-liquid equilibrium data of the systems of p-cymene (1) + (−)-β-caryophyllene (2) and p-cymene (1) + (−)-β-caryophyllene (2) + dehydroabietic acid (3) were determined by headspace gas chromatography at resin tapping temperature of 313.15, 323.15, and 333.15 K. Significant findingsThe experimental data showed that the addition of dehydroabietic acid significantly reduced the relative volatility of p-cymene to (−)-β-caryophyllene, and inhibited the separation of (−)-β-caryophyllene and p-cymene. The thermodynamic consistency of binary system was verified by Redlich Kister area test and Van Ness point test, while the thermodynamic consistency of ternary system was verified by Van Ness point test. The experimental data were compared with the calculated value by the NRTL, Wilson, and UNIQUAC models. The average absolute deviation of the vapor phase molar fraction was not more than 0.3%. In addition, the NRTL model was the most appropriate model.