Van't Hoff law for temperature dependent Langmuir constants in clathrate hydrate nanocavities

TL;DR

This paper derives a van't Hoff law for Langmuir constants in clathrate hydrate nanocavities, enabling prediction of gas occupancy based on temperature and cavity environment, validated against experimental data.

Contribution

It introduces a van't Hoff law expression for Langmuir constants in clathrate hydrates, derived from pairwise interaction potentials, for improved occupancy predictions.

Findings

Parameters enable calculation of hydrate compositions.

Validated approach with experimental data for ethane and cyclopropane.

Applicable to multiple gas species in different hydrate structures.

Abstract

This work gives a van't Hoff law expression of Langmuir constants of different species for determining their occupancy in the nanocavities of clathrate hydrates. The van't Hoff law's parameters are derived from a fit with Langmuir constants calculated using a pairwise site-site interaction potential to model the anisotropic potential environment in the cavities, as a function of temperature. The parameters can be used for calculating clathrates compositions. Results are given for nineteen gas species trapped in the small and large cavities of structure types I and II [1]. The accuracy of this approach is based on a comparison with available experimental data for ethane and cyclo- propane clathrate hydrates. The numerical method applied in this work, was recently validated from a comparison with the spherical cell method based on analytical considerations [1]