On the application of binary correction factors in lattice distortion calculations for methane clathrate hydrates

Abstract

The lattice distortion theory of Zele and co-workers is an attractive method for amending calculated phase equilibria of clathrate hydrates, since only two molecular computations are required. The perturbation energy between the empty and loaded clathrate hydrate lattice is the quantity of interest. The effect of binary correction factors applied to the Lorentz and Berthelot combining rules for the intermolecular interaction between gas and water particles is investigated. There are clear trends for the perturbation energy and lattice constant in terms of the binary correction factors, although there is significant sensitivity to the force field parameterization of the gas species.

Keywords:

• clathrate hydrate
• methane
• water
• thermodynamics

Acknowledgements

This work is based on research supported by the South African Research Chairs Initiative of the Department of Science and Technology and National Research Foundation as well as the Swedish International Development Cooperation Agency. The authors would like to thank the NRF Focus Area Programme and the NRF Thuthuka Programme. The authors are grateful to Stiftelsen Förenings Sparbanken who financed the computing facilities.