Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Temperature-dependent phase behavior of ionic liquid solutions containing N-butylpyridinium nitrate, water, and either sodium or ammonium citrate

Li, Y.[Yuliang], Luo, Q.[Qinxin], Xu, Z.[Zhongyu]
Fluid Phase Equilib. 2015, 403, 118-128
ABSTRACT
The aim of this work was to investigate the biphasic systems equilibrium behavior of solutions of Nbutylpyridinium nitrate and either sodium citrate or ammonium citrate to understand their liquid liquid equilibrium and the salting-out ability of these citrate salts. For this purpose, phase diagrams and liquid liquid equilibrium data of the investigated biphasic systems were determined experimentally from 298.15 K to 328.15 K. The binodal curves were then fit to an empirical nonlinear expression developed by Merchuk and to other models. The tie lines were also described by four equations. The results demonstrated that temperature has little influence on the phase behavior and the liquid liquid equilibrium within the investigated temperature range. The factors that affect the binodal curves, such as the salts, were also investigated. The salting-out ability, described by the effective excluded volume, of sodium citrate was greater than that of ammonium citrate, which may be related to the Gibbs free energy of hydration for the involved ions.
Compounds
# Formula Name
1 C6H17N3O7 ammonium 2-hydroxypropane-1,2,3-tricarboxylate
2 H2O water
3 C9H14N2O3 1-butylpyridinium nitrate
4 C6H5Na3O7 trisodium citrate
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
  • Mole fraction - 1 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mole fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 182
  • POMD
  • 1
  • 2
  • 3
  • Mole fraction - 1 ; Liquid mixture 1
  • Mole fraction - 3 ; Liquid mixture 2
  • Mole fraction - 1 ; Liquid mixture 2
  • Temperature, K; Liquid mixture 2
  • Mole fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 2
  • Liquid mixture 1
  • Liquid mixture 2
  • atomic absorption spectroscopy
  • atomic absorption spectroscopy
  • atomic absorption spectroscopy
  • 40
  • POMD
  • 4
  • 2
  • 3
  • Mole fraction - 4 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mole fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 314
  • POMD
  • 4
  • 2
  • 3
  • Mole fraction - 4 ; Liquid mixture 2
  • Mole fraction - 4 ; Liquid mixture 1
  • Mole fraction - 3 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mole fraction - 3; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • atomic absorption spectroscopy
  • atomic absorption spectroscopy
  • atomic absorption spectroscopy
  • 39