Thermal conductivity and thermal diffusivity of methane hydrate formed from compacted granular ice

Thermal conductivity and thermal diffusivity of pure methane hydrate samples, formed from compacted granular ice (0-75m), and were measured simultaneously by the transient plane source (TPS) technique. The temperature dependence was measured between 263.15 and 283.05K, and the gas-phase pressure dependence was measured between 2 and 10MPa. It is revealed that the thermal conductivity of pure methane hydrate exhibits a positive trend with temperature and increases from 0.4877 to 0.5467Wm(-1)K(-1). The thermal diffusivity of methane hydrate has inverse dependence on temperature and the values in the temperature range from 0.2940 to 0.3754mm(2)s(-1), which is more than twice that of water. The experimental results show that the effects of gas-phase pressure on the thermal conductivity and thermal diffusivity are very small. Thermal conductivity of methane hydrate is found to have weakly positive gas-phase pressure dependence, whereas the thermal diffusivity has slightly negative trend with gas-phase pressure.