LAUSR

ABSTRACT The dissociation of planar mixed hydrogen-/propane-hydrate in contact with water has been studied by molecular dynamics between 260 and 320 K. Two modes of termination of the hydrate interface were chosen: direct cleavage to produce an 001-surface, as well as one with completed cages. Substantial differences in melting points and initial dissociation kinetics were evident between both kinds of surface. These break-up rates were significantly dependent on temperature. A kinetic model was applied to fit dissociation profiles, clarifying crisply two hydrate dissociation regions; after a temperature-sensitive decomposition stage, a well-characterised lattice-collapse process is, by and large, insensitive to temperature. For hydrate-liquid systems at thermal equilibrium, consideration of relaxation times of auto-correlation functions of clathrate-molecule-number fluctuations shows significant differences between the two modes of interface: a unifying relationship was established between the non-equilibrium break-up rate from outright melting and that inferred from fluctuation-dissipation at equilibrium. GRAPHICAL ABSTRACT