An experimental study has been performed involving water spraying onto a cooled metal-block surface exposed to a hydrate-forming gas as a means of high-rate hydrate formation for the purpose of for example, natural-gas storage. Special attention has been paid to the effectiveness of conductive cooling through the metal block for directly removing the heat released by the hydrate formation from its site, that is, the surface of the metal block, and, thereby, increasing the rate of hydrate formation. HFC-32 (CH2F2) that forms a structure-I hydrate at moderate pressures was used as a model gas to enable visual observations of the hydrate formation inside a large-windowed spray chamber. The experiments revealed that the cooling by the metal block effectively increases the rate of hydrate formation while water is sprayed at a given volumetric rate and at a given degree of subcooling from the guest-gas/water/hydrate equilibrium temperature. (c) 2006 American Institute of Chemical Engineers.