Promotion of methane hydrate dissociation by underwater ultrasonic wave

The methane hydrate that exists in the abyssal floor is receiving attention as a nonconventional type of natural gas resource. An efficient dissociation technology is necessary and indispensable to achieve a steady supply of methane from methane hydrate because it does not easily dissociate in a stable environment of high pressure and low temperature. We consider that underwater ultrasonic wave irradiation may be a method of promoting the dissociation of methane hydrate on the basis of the facilitator effect. We carried out a preliminary examination using dry ice at various pressures, water temperatures, and input electric power. Methane hydrate was similarly examined. As a result, it was clarified that the dissociation time was shorted by the ultrasonic wave, and the wave was effective when the water temperature was low at the time of dissociation.