Study on the Optical Measurement of CO_2 Clathlate Hydrate MembraneThickness

摘要

The technology of the deep-ocean CO2 storage is expected to directly mitigate the source of the global warming. At deep-ocean condition above 4.45MPa and below 283K, the CO_2 clathrate hydrate (abbreviated to "hydrate" here after) crystals are formed as membrane at the interface between the liquid-water phase and the liquid-CO_2 phase. Since the strength and the thickness of the hydrate membrane are crucial to the storage period, it is important to experimentally measure the mechanical characteristics of the hydrate membrane and the hydrate droplet. In the previous study, high peak in the strength of the hydrate membrane is observed just below the dissociation temperature. But for lack of the membrane thickness data in a variety of parameter conditions, there is no experimental information about the mechanism of this high peak of the strength. In the present study, the measurements of the membrane thickness are conducted by using the laser-light interference method. It is clarified that the present method by using the beam light interference method is applicable to measure the hydrate membrane. The hydrate membrane thickness is estimated to be about 7 μw ～11 μm at 10MPa and 275K～283K.