Atomistic molecular dynamics simulations of H 2O diffusivity in liquid and supercritical CO 2

Othonas A. Moultos, Gustavo A. Orozco, Ioannis N. Tsimpanogiannis, Athanassios Z. Panagiotopoulos, Ioannis Economou

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19 Citations (Scopus)

Abstract

Molecular dynamics simulations were employed for the calculation of diffusion coefficients of pure CO2 and of H2O in CO2 over a wide range of temperatures (298.15 K < T < 523.15 K) and pressures (5.0 MPa < P < 100.0 MPa), that are of interest to CO2 capture-and-sequestration processes. Various combinations of existing fixed-point-charge force-fields for H2O (TIP4P/2005 and Exponential-6) and CO2 (elementary physical model 2 [EPM2], transferable potentials for phase equilibria [TraPPE], and Exponential-6) were tested. All force-field combinations qualitatively reproduce the trends of the experimental data for infinitely diluted H2O in CO2; however, TIP4P/2005-EPM2, TIP4P/2005-TraPPE and Exponential-6-Exponential-6 were found to be the most consistent. Additionally, for H2O compositions ranging from infinite dilution to, the Maxwell-Stefan diffusion coefficient is shown to have a weak non-linear composition dependence.

Original languageEnglish
Pages (from-to)2805-2814
Number of pages10
JournalMolecular Physics
Volume113
Issue number17-18
DOIs
Publication statusPublished - 17 Sep 2015

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Keywords

  • CO
  • diffusion coefficients
  • force-fields
  • HO
  • molecular dynamics simulation

ASJC Scopus subject areas

  • Biophysics
  • Molecular Biology
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

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