Massive amounts of gas hydrates occur naturally in the pores of
sediments or fractures in permafrost regions and beneath the oceans. For
hydrate formation in confinement, the equilibrium condition can shift to
harsher conditions, lowering the water activity, and subsequently
depressing the hydrate freezing temperature at a given pressure.
Conversely, the nucleation and rate of hydrate formation, as well as
hydrate conversion can be increased in confinement. Therefore, reliable
assessment of the hydrate distribution in nature requires accurate
thermodynamic and kinetic models of hydrate formation; however, these
models tend to be based upon the properties of bulk hydrates. Hydrate
formation and growth promotion in confinement are potentially
interesting for hydrate technological applications, such as gas
separation, energy storage, and flow assurance. This paper reviews the
thermodynamic and kinetic properties and their interrelations of gas
hydrates in confined spaces.