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Title: A semi-empirical molecular statistical thermodynamic model for calculating standard molar Gibbs energies of aqueous species above and below the critical point of water

Journal Article · · Journal of Molecular Liquids
 [1];  [1];  [2];  [3]
  1. Pennsylvania State Univ., University Park, PA (United States)
  2. St. Petersburg State Univ., St. Petersburg (Russia)
  3. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

An increasing number of industrial applications rely on controlling solutes in water above and below its critical point. Processes such as hydrothermal synthesis, steam power generation and ultra-high enthalpy geothermal power are all influenced by factors such as mineral precipitation, pH and solute speciation. Here, the supercritical point of water is remarkable in that slight changes in temperature and pressure can cause dramatic changes in some solute properties. Here, it was found that our approach reliant on molecular statistical thermodynamic expressions for hard sphere (HS), ion-dipole and dipole-dipole interactions via mean spherical approximation (MSA) provided excellent agreement to available experimental data. In addition to model parameters having some physical meaning, this approach used less adjustable parameters than the well-known Helgeson-Kirkham-Flowers (HKF) model. Furthermore, the model was used to obtain standard thermodynamic values for HCl0(aq), KCl0(aq) and NaOH0(aq) ion pairs. In total, modeling parameters for 10 different aqueous species were obtained to demonstrate the capabilities of the approach.

Research Organization:
National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
Sponsoring Organization:
FE; USDOE
OSTI ID:
1509715
Report Number(s):
NETL-PUB-21649
Journal Information:
Journal of Molecular Liquids, Vol. 270, Issue C; ISSN 0167-7322
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 7 works
Citation information provided by
Web of Science