Microscopic Insights into the Formation of Methane Hydrate in the Absence/Presence of Electrolyte Ions

摘要

The formation of methane hydrate can be effectively inhibited by the electrolyte ions, but it remains to be a long-term challenge to describe its molecular mechanism. In this work, molecular dynamics simulations were performed to explore the inhibition process of electrolyte solutions at molecular level. The simulation results manifest that the presence of electrolyte ions reduces the possibility of water molecules forming cage clusters of hydrates. Additionally, the growth rate of hydrates is closely related to the ionic concentration and ionic strength of the electrolyte solutions while has no obvious relationship with the ionic species. Finally, the defect structure of the hydrate was noticed and it was found that a little of ions can replace the water molecules in the clathrate structure to form a cage.