A theoretical study of the dissociation of the sI methane hydrate induced by an external electric field

• Published in: The Journal of Chemical Physics
• Main Authors: Luis, D. P., Herrera-Hernández, E. C., Saint-Martin, H.
• Other Authors: CONACYT, DGTIC-UNAM, ICF-UNAM
• Format: Article in Journal/Newspaper
• Language: English
• Published: AIP Publishing 2015
• Subjects: Methane hydrate
• Online Access: http://dx.doi.org/10.1063/1.4936214; https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.4936214/15505820/204503_1_online.pdf

Molecular dynamics simulations in the equilibrium isobaric—isothermal (NPT) ensemble were used to examine the strength of an external electric field required to dissociate the methane hydrate sI structure. The water molecules were modeled using the four-site TIP4P/Ice analytical potential and methane was described as a simple Lennard-Jones interaction site. A series of simulations were performed at T = 260 K with P = 80 bars and at T = 285 K with P = 400 bars with an applied electric field ranging from 1.0 V nm−1 to 5.0 V nm−1. For both (T,P) conditions, applying a field greater than 1.5 V nm−1 resulted in the orientation of the water molecules such that an ice Ih–type structure was formed, from which the methane was segregated. When the simulations were continued without the external field, the ice-like structures became disordered, resulting in two separate phases: gas methane and liquid water.