On the Thermodynamic Stability of Clathrate Hydrates VI: Complete Phase Diagram

Hideki Tanaka, Takuma Yagasaki, Masakazu Matsumoto

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)

    Abstract

    We develop a method to evaluate the thermodynamic stability of clathrate hydrates relative to host water and/or guest species. This enables to investigate complete phase behaviors of clathrate hydrates in the whole space of the thermodynamic variables, not only temperature and pressure but also composition, with only the intermolecular interactions as input parameters. A complete phase diagram of clathrate hydrate is settled with this method, specifically the region enclosed by the hydrate/water and hydrate/guest phase boundaries where a clathrate hydrate is the only stable phase. The method is applied to methane clathrate hydrate, which results in an excellent agreement in dissociation pressure with the experimental observations. It is found that the hydrate/water phase boundary is significantly affected by the phase transition of water from ice to liquid. This transition limits the stable area of the clathrate hydrate terminated at the dissociation temperature, which otherwise exhibits unphysical divergence. It is essential to choose a pressure as an independent variable so as to calculate the accurate phase equilibria in composition space. The present method establishes a pressure-temperature-composition relation for a single stable phase of clathrate hydrate as well as recovering its temperature dependence of the dissociation pressure.

    Original languageEnglish
    Pages (from-to)297-308
    Number of pages12
    JournalJournal of Physical Chemistry B
    Volume122
    Issue number1
    DOIs
    Publication statusPublished - Jan 11 2018

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Surfaces, Coatings and Films
    • Materials Chemistry

    Fingerprint

    Dive into the research topics of 'On the Thermodynamic Stability of Clathrate Hydrates VI: Complete Phase Diagram'. Together they form a unique fingerprint.

    Cite this