Molecular dynamics simulation of Henry's constant of argon, nitrogen, methane and oxygen in ethylene oxide

Abstract

Molecular dynamics simulations have been carried out to estimate the Henry's constants and solubilities of a range of small nonpolar molecules in ethylene oxide using a scheme that closely mimics experiments. Our results show that the method is reliable for polar–nonpolar sytems, which are generally notoriously difficult to investigate using classical methods. By validating the results for several gases for which experimental results are available, we have been able to estimate the solubility of oxygen, for which experiments have yet to be carried out because of flammability concerns. Our studies have also allowed us to develop a simple correlation for predicting the dependence of Henry's constant on binary interaction parameters. Finally, we also observe that for gas solubilities, small diatomics can effectively be approximated by central Lennard–Jones potential models. This can simplify such simulations considerably.

Keywords:

• Molecular dynamics
• Henry's constant
• Polar system
• Gas Solubility

Acknowledgements

This research was supported by grants from the National Science Foundations (CTS-0314023) and the Petroleum Research Fund administered by the American Chemical Society. The authors would like to thank Drs J. T. Miller (British Petroleum) and Y. Chernyak (Huntsman Corp.) for helpful discussions.