Visualization of Molecular Dynamics by Simulation
The mechanism of formation of methane hydrate is investigated here at a molecular level. The key to whether or not methane hydrates can be formed is the stability of the hydrate structure. This paper deals with a computer simulation of methane hydrate type 1 formation by a molecular dynamics method and an accurate description of the crystal structure. Computer simulation results show that very stable type 1 methane hydrates can be formed below 275 K, in which 46 water and 8 methane molecules are contained in a single cubic unit cell of length 12.0 . Above 275 K, the stability of the hydrates increasingly degrades, logarithmically as a power function, up to 300 K, with no stability at 350 K. Pressure, as a parameter of formation conditions, increases with temperature and becomes tremendously high at 350 K. Hydrates with various hydration numbers (at least one guest molecule in a small cage) have roughly the same degree of stability, but higher pressures are required for hydrates with fewer guest molecules. Empty hydrates dissolve above 275 K.
molecular dynamics simulation methane hydrate structure