Thermal conductivities of methane-methylcyclohexane and tetrabutylammonium bromide clathrate hydrate

Thermal conductivities of structure H (sH) methane-methylcyclohexane hydrate and type A tetrabutylammonium bromide (TBAB) clathrate hydrate were measured using a single-sided transient plane source technique. The thermal conductivity of sH hydrate exhibited a positive trend with temperature and the average thermal conductivity was found to be 0.44 W m(-1) K-1 at a compaction pressure of 12 MPa. The thermal conductivity of sH hydrate was lower than those of structure I and structure II hydrates at the same temperature and was found to depend not only on guest-host interactions but also on the rigidity of the framework. Unlike sH hydrates, the thermal conductivity of type A TBAB hydrates exhibited a negative trend with temperature. One possible reason for this strange phenomenon could be that the TBAB hydrate has a semi-clathrate structure, which retains the crystal heat transmission characteristics. The structures of the hydrates studied were different from those of normal gas hydrates. In addition, the thermal conductivity values for TBAB hydrates were also affected by interactions between the cations and anions.