Abstract

Hydrate dissociation is involved in some practical processes, such as exploiting natural gas hydrates, resolving the plugging hazards, and developing industrial techniques. The decomposition mechanisms of gas hydrate above and below ice point are quite different. The presence of porous media may also result in the complication of hydrate dissociation compared with bulk water/hydrate system. In this work, the recent progresses achieved in the dissociation kinetics of gas hydrate from three aspects: dissociation kinetics of hydrate in bulk hydrate/water system above ice point, dissociation kinetics of hydrate in bulk hydrate/water system below ice point, and dissociation kinetics of hydrate in porous media, were reviewed. The influences of temperature, pressure, gas composition, and additive of aqueous phase such as inhibitors and promoters on the dissociation of hydrate have been examined. The corresponding mechanisms and models for hydrate dissociation under three aspects were also reviewed. A prospect to the future of research on gas hydrate dissociation is given.

Keywords: Anomalous preservation, Depressurization, Dissociation, Heat transfer, Hydrate, Inhibitor injection, Intrinsic kinetic, Kinetics, Mass transfer, Mechanism, Model, Porous media, Thermal stimulation