The phase equilibrium relationships
of resin systems
are indispensable
for resin tapping, distillation, and investigating the release of
terpenes in biogenic volatile organic compounds (BVOCs). Herein, we
obtained the vapor–liquid equilibrium (VLE) data of monoterpene-sesquiterpene
systems that contain resin acid by a headspace gas chromatography
(HS-GC). There is no azeotropic behavior between terpenes, and abietic
acid was found to inhibit the volatilization and separation of terpenes.
Furthermore, the saturated vapor pressure of the systems almost triples
when the experimental temperature increases from 313.15 to 333.15
K, which may exacerbate terpene emissions in ecosystems. Additionally,
the thermodynamic consistency of the VLE values was confirmed by van
Ness test, and the experimental data were correlated using NRTL, UNIQUAC,
and Wilson activity coefficient models, while the Conductor-like
Screening Model for Real Solvents (COSMO-RS) model was utilized for
predictions. All of the data satisfy thermodynamic consistency, and
the correlation results and prediction results demonstrate good adherence
of the activity coefficient models to experimental values and the
positive capacity of COSMO-RS in predicting the VLE relationship for
the pine resin systems, respectively.