Overview of Molecular Dynamics Simulation of Natural Gas Hydrate at Nanoscale

Figure 7

A snapshot of the simulation process of liquid CO₂ (orange globule) replacing methane gas in methane hydrate (blue globule). (a) 0 ns; (b) 10 ns; (c) 20 ns; (d) 40 ns; (e) 180 ns. The green line represents hydrogen bonds between water molecules. The system initially (a) consists of a layer of crystalline methane hydrate and a liquid carbon dioxide phase (intermediate). Layer IDs (#1 to #3) are marked in (a). Almost all methane molecules in #2 layer are replaced by CO₂ in 20 ns (c), and part methane molecules are further replaced by CO₂ in 20~180 ns (d and e) (from reference [96]).

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(b)

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(e)