Optimization of intermolecular potential parameters for the CO2/H2O mixture

Gustavo A. Orozco, Ioannis Economou, Athanassios Z. Panagiotopoulos

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Monte Carlo simulations in the Gibbs ensemble were used to obtain optimized intermolecular potential parameters to describe the phase behavior of the mixture CO2/H2O, over a range of temperatures and pressures relevant for carbon capture and sequestration processes. Commonly used fixed-point-charge force fields that include Lennard-Jones 12-6 (LJ) or exponential-6 (Exp-6) terms were used to describe CO2 and H2O intermolecular interactions. For force fields based on the LJ functional form, changes of the unlike interactions produced higher variations in the H2O-rich phase than in the CO2-rich phase. A major finding of the present study is that for these potentials, no combination of unlike interaction parameters is able to adequately represent properties of both phases. Changes to the partial charges of H2O were found to produce significant variations in both phases and are able to fit experimental data in both phases, at the cost of inaccuracies for the pure H2O properties. By contrast, for the Exp-6 case, optimization of a single parameter, the oxygen-oxygen unlike-pair interaction, was found sufficient to give accurate predictions of the solubilities in both phases while preserving accuracy in the pure component properties. These models are thus recommended for future molecular simulation studies of CO2/H2O mixtures.

Original languageEnglish
Pages (from-to)11504-11511
Number of pages8
JournalJournal of Physical Chemistry B
Volume118
Issue number39
DOIs
Publication statusPublished - 2 Oct 2014

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Carbon Sequestration
Oxygen
Carbon capture
optimization
Phase behavior
Solubility
field theory (physics)
interactions
Pressure
Temperature
oxygen
preserving
solubility
simulation
carbon
predictions
temperature
Monte Carlo simulation

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry
  • Materials Chemistry

Cite this

Optimization of intermolecular potential parameters for the CO2/H2O mixture. / Orozco, Gustavo A.; Economou, Ioannis; Panagiotopoulos, Athanassios Z.

In: Journal of Physical Chemistry B, Vol. 118, No. 39, 02.10.2014, p. 11504-11511.

Research output: Contribution to journalArticle

Orozco, Gustavo A. ; Economou, Ioannis ; Panagiotopoulos, Athanassios Z. / Optimization of intermolecular potential parameters for the CO2/H2O mixture. In: Journal of Physical Chemistry B. 2014 ; Vol. 118, No. 39. pp. 11504-11511.
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