Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Phase Diagrams of Ammonium Sulfate + Ethanol/1-Propanol/2-Propanol + Water Aqueous Two-Phase Systems at 298.15 K and Correlation

Wang, Y.[Yun], Yan, Y.[Yongsheng], Hu, S.[Shiping], Han, J.[Juan], Xu, X.[Xiaohui]
J. Chem. Eng. Data 2010, 55, 2, 876-881
ABSTRACT
Binodal data for the ethanol/1-propanol/2-propanol + ammonium sulfate + water systems were determined at 298.15 K. On the basis of an empirical equation and lever rule, the liquid-liquid equilibrium compositions of the ethanol + ammonium sulfate + water system were directly calculated by Matlab. The Othmer-Tobias equation and Bancroft equation proved the reliability of the calculation method and the corresponding tie-line data. The phase-separation abilities of hydrophilic alcohols were compared by the effective excluded volume (EEV) of salt and the binodal curves plotted in molality. The phase-separation abilities of the investigated alcohols are in the order of 1-propanol greater than 2-propanol greater than ethanol greater than methanol. The mechanism of phase separation and the effects of alcohols, salts, and pH values are also discussed. The results show that the increase in the amount of phase-forming substance and the decrease in pH values (from 9.03 to 3.58) are both advantageous to the formation of the aqueous two-phase system (ATPS).
Compounds
# Formula Name
1 C2H6O ethanol
2 H2O water
3 H8N2O4S ammonium sulfate
4 C3H8O propan-1-ol
5 C3H8O propan-2-ol
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
  • 3
  • Mass fraction - 3 ; Liquid mixture 1
  • Mass fraction - 1; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 48
  • POMD
  • 1
  • 2
  • 3
  • Mass fraction - 3 ; Liquid
  • Mass fraction - 1; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 3
  • Titration method
  • 4
  • POMD
  • 1
  • 2
  • 3
  • Mass fraction - 3 ; Liquid mixture 2
  • Mass fraction - 3 ; Liquid mixture 1
  • Mass fraction - 1 ; Liquid mixture 1
  • Mass fraction - 1; Liquid mixture 2
  • Temperature, K; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 2
  • Liquid mixture 2
  • Liquid mixture 1
  • OTHER
  • OTHER
  • OTHER
  • 6
  • POMD
  • 4
  • 2
  • 3
  • Mass fraction - 3 ; Liquid mixture 1
  • Mass fraction - 4; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 44
  • POMD
  • 5
  • 2
  • 3
  • Mass fraction - 3 ; Liquid mixture 1
  • Mass fraction - 5; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 49