Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Determination and modeling of the solubilities of NH4Al(SO4)2 12H2O in the NH4+ -Al3+ -H3O+ -HSO4- -SO4 2- -H2O system at different H2SO4 molalities and temperatures

Xu, D.[Dehua], Li, H.[Huiquan], Wang, C.[Chenye], Bao, W.[Weijun]
Fluid Phase Equilib. 2015, 403, 129-135
ABSTRACT
Solubilities of NH4Al(SO4)2 12H2O in the NH4 + -Al3+ -H3O+ -HSO4- -SO4 2- -H2O system, as well as the densities of the saturated solution were measured at the temperature range from 293.15 to 323.15 K and at the H2SO4 molalities varying from 0.6 to 3.6 mol/kg. At the same temperature and H2SO4 molality, the solubilities of (NH4)2SO4 sharply deceased with the addition of Al2(SO4)3 from 0 to a turning point at first and then slightly decreased. The electrolyte NRTL model embedded in Aspen plus was applied to model the solubilities of NH4Al(SO4)2 12H2O in the NH4 + -Al3+ -H3O+ -HSO4- -SO4 2- -H2O system. The model parameters were obtained via regressing the experimental results and the total relative average deviation of temperature is 1.04%, indicating that the calculation values are good with experiment data. With the newly obtained model parameters, the fundamental solubilities of NH4Al(SO4)2 12H2O in the NH4 + -Al3+ -H3O+ -HSO4- -SO4 2- -H2O system can be calculated precisely for its crystallization process.
Compounds
# Formula Name
1 H2O water
2 AlH4NO8S2 aluminum ammonium sulfate
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
  • Molality, mol/kg - 2 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 2
  • gravimetric method
  • 15