Predicting thermodynamic stability of clathrate hydrates based on molecular-dynamics simulations and its confirmation by phase-equilibrium measurements

Tatsuya Miyoshi, Ryo Ohmura, Keiyi Yasuoka

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

In order to establish a method to predict the formation of new clathrate hydrates under milder temperature-pressure conditions, we performed a molecular-dynamics (MD)-based free energy calculation, and then hydrate phase equilibrium measurements were done to confirm the prediction. The free energy differences are calculated for the structure-H hydrates each formed with methane and each of the following large-molecule guest substances: 2-methylbutane, 2,3-dimethylbutane, 2,2-dimethylbutane, 2,2,3-trimethybutane, and 2,2,3,3-tetramethylbutane. MD simulations were performed under a constant pressure and temperature with 6120 TIP4P water molecules, 900 OPLS-UA methane molecules, and a multisite modeled 180 OPLS-UA LMGS molecule. The results of the free energy calculation indicated the structure-H hydrate formed with 2,2,3,3-tetramethylbutane is the most stable hydrate although the relevant equilibrium pressure data were not previously reported in the literature. The experimental phase equilibrium measurement performed in the present study confirmed this prediction, thereby supporting the predictive utility of the MD-based free energy calculation.

Original languageEnglish
Pages (from-to)3799-3802
Number of pages4
JournalJournal of Physical Chemistry C
Volume111
Issue number9
DOIs
Publication statusPublished - 2007 Mar 8

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Predicting thermodynamic stability of clathrate hydrates based on molecular-dynamics simulations and its confirmation by phase-equilibrium measurements'. Together they form a unique fingerprint.

  • Cite this