The growth of sII type methane hydrate influenced by thermodynamic inhibitors

Thermodynamic inhibitors are broadly used to prevent hydrate formation in hydrate exploitation and trans-portation of natural gas. Molecular dynamics simulations of sII type methane hydrate growth influenced by thermodynamic inhibitors, including NaCl, ethylene glycol and triethylene glycol, are implemented. It has been found that the dissolution rate of methane bubble as well as hydrate growth rate are decreased by the three inhibitors. The role of inhibitors is compared and the inhibition effect of triethylene glycol is the best due to the higher number of formed H-bonds and stronger energy interaction with water. The geometric defects structure of Na+, Cl- ions and triethylene glycol molecules is analyzed and the bubble protection mechanism for triethylene glycol is elucidated. The microscopic mechanism of sII type methane hydrate growth influenced by thermody-namic inhibitors found in the present study is conducive to revealing the inhibition mechanisms of traditional inhibitors and designing novel inhibitors.