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Updated: Jun 7, 2026
08:46
Methane Hydrate Crystallization on Sessile Water Droplets
Published on: May 26, 2021
Observation of two-step nucleation in methane hydrates
Jenel Vatamanu1, Peter G Kusalik
1Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada.
Physical Chemistry Chemical Physics : PCCP
|October 20, 2010
Summary
Homogeneous nucleation of methane hydrate is a rapid, two-step process. Disordered solid-like structures form first, then evolve into crystals, without requiring prior crystal memory.
Area of Science:
- Geochemistry
- Materials Science
- Chemical Engineering
Background:
- Gas hydrate nucleation is crucial for understanding natural gas storage and transport.
- Previous studies suggested complex nucleation pathways for methane hydrate.
- The role of pre-nucleation structures and memory effects remained debated.
Purpose of the Study:
- To investigate the kinetics and mechanism of homogeneous methane hydrate nucleation.
- To characterize the initial stages of hydrate crystal formation.
- To clarify the influence of local methane concentration on nucleation and re-crystallization.
Main Methods:
- Molecular dynamics simulations were employed to model methane hydrate nucleation.
- Analysis focused on structural evolution, molecular diffusion, and energy landscapes.
- Simulations tracked the transition from disordered structures to crystalline phases.
Main Results:
- Homogeneous nucleation of methane hydrate can occur within tens of nanoseconds.
- A two-step nucleation process was observed: disordered solid-like structures followed by crystalline forms.
- The initial solid-like state is post-critical, exhibiting short-range order and solid-like properties with some mobility.
- Fast re-crystallization is driven by local methane enrichment, not by a 'memory' of previous crystals.
Conclusions:
- Methane hydrate nucleation is a rapid process involving a distinct pre-crystalline solid-like state.
- The 'memory effect' in methane hydrate re-crystallization is attributed to local methane concentration.
- These findings suggest potential for greater polycrystallinity and novel methane hydrate phases.
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