Molecular Dynamics Simulation of Decomposition of Methane Hydrate and Interfacial Characteristics in Nanostructure Region

A comprehensive review on molecular dynamics simulation studies of phenomena and characteristics associated with clathrate hydrates

“…MD simulations confirmed that the two-steps dissociation model which was introduced by Sloan [1] is reliable for the mechanism of hydrate dissociation [82] in which the dissociation rate directly depends on the fractional occupancy [112]. Also, expanding the waterhydrate interfacial contact area and higher initial temperature can effectively promote hydrate decomposition [113]. It was proved that the thermal-driven breakup of CH4 hydrate is controlled by the diffusion of CH4 molecules from the hydrate surface to the liquid phase; additionally, break-up for empty hydrate was determined about an order of magnitude faster than filled clathrate hydrate [79].…”

“…This is mainly followed by the escape of guest molecules from broken hydrate cages and then aggregating together [82]. Although the resistance of heat and mass transfer during the dissociation increases, it mostly reduces the rate of CH4 hydrate decomposition [113].…”

Interfacial thermal transport in combustion-dissociation process at different environments for methane hydrate

“…6 shows the heat flux at burning boundary and the solid-liquid interface at ratios of oxygen-fuel of 0.5, 1.0 and 2.0, and the interfacial heat flux is calculated by Eq (1). According to Li et al [23,24,25,26],…”

“…Wu et al [22] studied the decomposition of methane hydrate coupled with chemical inhibitors and thermal stimulus and found that the accelerated effect of alcohol on accelerating the decomposition of hydrate is very obvious. With the development of the study on gas hydrate, the attention has gradually shifted from the characterization of the process of decomposition of hydrate to the interface generated by decomposed hydrate [23,24,25,26], which is formed due to the phase transition in the process of decomposition. The interface is the heart of thermal transport because the dissociation of hydrate is carried out under the combined action of heat and mass transfer [24].…”

“…The dissociation of methane hydrate with burning is more complicated, and the liquid water from decomposed hydrate is contact in direct with free gas to produce a gas-liquid interface, the outer side of which is the area of burning methane, and the interface is defined as burning boundary. Accurate positioning of solid-liquid interface and burning boundary is the basis for exploring interfacial thermal transport, and these researches [23,24,25,26] provide valuable perspectives for locating interfaces.…”