10.6084/m9.figshare.6429083.v1
Fengfeng Gao
Fengfeng
Gao
Krishna M. Gupta
Krishna M.
Gupta
Shiling Yuan
Shiling
Yuan
Jianwen Jiang
Jianwen
Jiang
Decomposition of CH<sub>4</sub> hydrate: effects of temperature and salt from molecular simulations
Taylor & Francis Group
2018
CH4 hydrate
decomposition
temperature
salt
molecular simulation
2018-06-04 12:38:20
Dataset
https://tandf.figshare.com/articles/dataset/Decomposition_of_CH_sub_4_sub_hydrate_effects_of_temperature_and_salt_from_molecular_simulations/6429083
<p>We report a molecular simulation study to investigate the decomposition of CH<sub>4</sub> hydrate. The decomposition is revealed to be stepwise from the outer to inner layers. Upon decomposition, the number of 5<sup>12</sup>6<sup>2</sup> cages drops faster than that of 5<sup>12</sup> cages. CH<sub>4</sub> molecules are released, dissolved in water, then enter gas phase; meanwhile, CH<sub>4</sub> bubbles may form particularly at a high temperature. Based on the variations of potential energy, order parameter, cage number and density profile of CH<sub>4</sub> at different temperatures (300, 330, 345 and 360 K) and NaCl concentrations (0, 0.6 and 1.8 M), the effects of temperature and salt are comprehensively examined. With increasing temperature, the decomposition in pure water is accelerated, whereas two opposite effects are observed in NaCl solution. At 330 K, the decomposition is retarded at a higher NaCl concentration, as attributed to the reduced CH<sub>4</sub> solubility in NaCl solution and the participation of ions in cage formation; at 360 K, however, the decomposition is accelerated when NaCl concentration increases due to bubble formation. This simulation study provides microscopic insights into hydrate decomposition, which might be useful towards the optimisation of operating conditions for CH<sub>4</sub> production from CH<sub>4</sub> hydrate.</p>