Methane hydrate: shifting the coexistence temperature to higher temperatures with an external electric field

Abstract

In the present work, we used molecular dynamic simulations of the equilibrium NPT ensemble to examine the effect of an external electric field on the three-phase coexistence temperature of methane gas, liquid water and methane hydrate. For these simulations, we used the TIP4P/Ice rigid water model and a single-site model for methane. The simulations were implemented at two pressures, 400 and 250 bar, over temperatures ranging from 285 to 320 K and from 280 to 315 K, respectively. The application of an external electric field in the range of 0.1–0.9 caused the effect of the thermal vibrations of the water molecules to become attenuated. This resulted in a shift of the three-phase coexistence temperature to higher temperatures. Electric fields below this range did not cause a difference in the coexistence temperature, and electric fields above this range enhanced the thermal effect. The shift had a magnitude of 22.5 K on average.

Keywords:

• Molecular dynamics
• methane clathrate
• external electric field

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

D.P. Luis thanks CONACyT for the support provided through the Cátedras CONACyT programme. The simulations in this work were performed on the supercomputer of DGTIC-UNAM and on the National Supercomputer Center (CNS) of IPICYT, A.C. HSM acknowledges the financial support from DGAPA-UNAM [grant number IN109915].