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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

Abstract

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 HCl 0(aq), KCl 0(aq) and NaOH 0(aq) ion pairs. In total, modeling parameters for 10 different aqueous species were obtained to demonstrate the capabilities of the approach.

Authors:
 [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)
Publication Date:
Research Org.:
National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
Sponsoring Org.:
FE; USDOE
OSTI Identifier:
1509715
Report Number(s):
NETL-PUB-21649
Journal ID: ISSN 0167-7322
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Molecular Liquids
Additional Journal Information:
Journal Volume: 270; Journal Issue: C; Journal ID: ISSN 0167-7322
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
Critical point of water; Aqueous species; Standard Gibbs energy of formation; High temperature; Mean spherical approximation; Molecular statistical thermodynamics

Citation Formats

Lvov, Serguei N., Hall, Derek M., Bandura, Andrei V., and Gamwo, Isaac K. A semi-empirical molecular statistical thermodynamic model for calculating standard molar Gibbs energies of aqueous species above and below the critical point of water. United States: N. p., 2018. Web. doi:10.1016/j.molliq.2018.01.074.
Lvov, Serguei N., Hall, Derek M., Bandura, Andrei V., & Gamwo, Isaac K. A semi-empirical molecular statistical thermodynamic model for calculating standard molar Gibbs energies of aqueous species above and below the critical point of water. United States. doi:10.1016/j.molliq.2018.01.074.
Lvov, Serguei N., Hall, Derek M., Bandura, Andrei V., and Gamwo, Isaac K. Fri . "A semi-empirical molecular statistical thermodynamic model for calculating standard molar Gibbs energies of aqueous species above and below the critical point of water". United States. doi:10.1016/j.molliq.2018.01.074. https://www.osti.gov/servlets/purl/1509715.
@article{osti_1509715,
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},
author = {Lvov, Serguei N. and Hall, Derek M. and Bandura, Andrei V. and Gamwo, Isaac K.},
abstractNote = {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.},
doi = {10.1016/j.molliq.2018.01.074},
journal = {Journal of Molecular Liquids},
number = C,
volume = 270,
place = {United States},
year = {2018},
month = {2}
}

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