New progress in characteristic of thermal conduction in hydrocarbon hydrates using molecular dynamics method has been made by Deqing Liang, Lihua Wan and other researchers from Chinese Academy of Sciences Guangzhou Institute of Energy.
Equilibrium molecular dynamics simulations and the Green-Kubo method are used to the sI hydrates of methane, ethane and ethene to study their thermal conduction at temperature 263.15 K and pressure 3 MPa.Thermal conductivities and mean densities of the hydrates are obtained. Characteristics of thermal conduction in hydrates of hydrocarbon such as methane, ethane or ethene are studied for the effects of host and guest molecules and compactness and regularity of the crystal lattice on thermal conduction. The results show that thermal conduction is similar for the hydrocarbon hydrates that resembles chemically with indistinct difference in molecular weight. The thermal conduction of these hydrocarbon hydrates has similar temperature and pressure dependence and similar crystal structure correlation. The influence of water on thermal conductivity of sI gas hydrates goes far beyond the effect of guest molecules on it. With higher mean molecular weight in hydrates, higher densities are more conducive to enhance the thermal conductivity. More compact crystal lattices improve thermal conductivities. With more regular lattice structures, phonon mean free paths are longer, so that the thermal conductivity of hydrate increases.
This work is financially supported by the National Natural Science Foundation of China, the Knowledge Innovation Program in Chinese Academy of Science and the National Natural Science Foundation of China-Guangdong. Some of their works were published in Journal of Chemical Industry and Engineering (China),in 2014, volume 65 issue 3.