Fluid Phase Equilibria, Vol.489, 111-116, 2019
Single-site Langmuir-type adsorption in structure-I clathrate hydrates: A molecular simulation study using a general self-consistent force field
This work reports on an investigation into the utility of a single-site approach to adsorption in structure-I clathrate hydrates through the consideration of a set of known clathrate hydrate-forming gases: carbon monoxide, methane, ethane, ethene, and hydrogen sulphide. Clathrate hydrates are an ice-like non-stoichiometric material consisting of a gas species that has been enclathrated by a hydrogen-bonded water lattice. The structure-I structure itself is a known solution to the Kelvin problem-i.e. a foam of approximately equal-volume bubbles with minimal inter-bubble surface area-and it has been previously demonstrated computationally for methane considered as a single pseudo-atom, that a single Langmuir-type site may suffice, since the cavities within the hydrate lattice do in fact have roughly equal volume. This study considers a broader range of structure-I clathrate hydrates using an explicit-atom approach, and demonstrates some of the limitations of this simplification. (C) 2019 Elsevier B.V. All rights reserved.