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Methane Hydrate Crystallization on Sessile Water Droplets
Published on: May 26, 2021
Molecular-dynamics simulations of methane hydrate dissociation
Niall J English1, J K Johnson, Charles E Taylor
1U.S. Department of Energy, National Energy Technology Laboratory, P.O. Box 10940, Pittsburgh, Pennsylvania 15236, USA. nenglish@chemcomp.com
The Journal of Chemical Physics
|January 7, 2006
Summary
Simulations show empty methane hydrate clusters dissolve faster than those with methane. Methane diffusion to the liquid layer controls breakup, with larger liquid phases reducing initial delays.
Area of Science:
- Physical Chemistry
- Materials Science
- Computational Science
Background:
- Methane hydrates are ice-like structures trapping methane.
- Understanding hydrate dissolution is crucial for energy and climate studies.
- Molecular dynamics simulations offer insights into nanoscale processes.
Purpose of the Study:
- Investigate methane hydrate crystallite dissolution rates.
- Determine factors influencing hydrate breakup dynamics.
- Compare the impact of methane occupation and system preparation on dissolution.
Main Methods:
- Employed nonequilibrium molecular-dynamics simulations.
- Simulated spherical methane hydrate crystallites in water or water-methane mixtures.
- Varied crystallite size, methane occupation, and liquid phase composition.
Main Results:
- Dissolution rates were similar across different crystal sizes.
- System preparation method did not significantly affect dissociation rates.
- Empty hydrates dissociated faster than those with 80-100% methane occupation.
- Methane diffusion to the liquid layer was identified as the rate-limiting step.
- Larger liquid phases reduced initial breakup delays.
Conclusions:
- Hydrate dissociation is primarily governed by methane diffusion.
- Empty hydrate clusters are less stable and dissolve more rapidly.
- Simulation methods for long-range electrostatics impact calculated dissociation rates.
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