Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Liquid-liquid equilibrium of 2-methyltetrahydrofuran/water over wide temperature range: Measurements and rigorous regression

Glass, M.[Moll], Aigner, M.[Maximilian], Viell, J.[Jorn], Jupke, A.[Andreas], Mitsos, A.[Alexander]
Fluid Phase Equilib. 2017, 433, 212-225
ABSTRACT
The liquid-liquid equilibrium (LLE) of the binary system 2-methyltetrahydrofuran (2MTHF)-water was determined experimentally and the Non-Random-Two-Liquid (NRTL) model was fitted to the experiments. To our knowledge, this work is the first i) to report measurement data in the temperature range from 293K to 423 K, and ii) to present a thermodynamic model including parameter values, capturing the LLE of this fluid system. The model fitting was conducted with both Aspen Properties and our in-house tool BOARPET that is based on the work of Mitsos et al. (A. Mitsos, G. M. Bollas, and P. I. Barton. Chem. Eng. Sci., 2009). From the regressed parameter values the Gibbs free energy was calculated in order to check thermodynamic stability. It was found that the results of Aspen violate thermodynamic stability even locally and thus, are not utilizable. In particular, Aspen determines phase compositions for which the Gibbs free energy is locally concave. This gives a hitherto unknown motivation to use rigorous problem formulation in parameter estimation. From experimental results it is evident that 2MTHF-water exhibits a stable biphasic system over a wide temperature range which makes it a promising solvent system candidate for reacting systems.
Compounds
# Formula Name
1 C5H10O 2-methyltetrahydrofuran
2 H2O water
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • FTIR spectroscopy
  • 6
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • Raman spectroscopy
  • 6
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Chromatography
  • 6
  • POMD
  • 1
  • 2
  • Mole fraction - 1 ; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • Chromatography
  • 6