A Deparameterized Clathrate Phase Description Using Crystallography Theory: Validating Guest-Swapping Dynamics in a Gas Hydrate

Parametric description of hydrate phase equilibrium has persisted as a major issue in clathrate science for more than the last six decades. To explore the long-awaited solution, a parameter-free hydrate phase equilibrium formulation was grounded very recently using crystallographic theory. However, before welcoming this new model from every desk, its widespread usage needs to be rigorously checked. In this light, this stochastic hydrate-phase thermodynamic formulation is integrated with a suitable vapor- and liquid-phase equilibrium model to propose and elucidate the thermokinetic formulation of guest gas swapping in clathrate hydrates. Identifying the kinetic parameters by formulating a global optimization strategy, the thermo (three-phase)-kinetic (fractional-order) swapping model is widely tested with lab-scale and field data in the presence of salt and porous media. In all of the cases investigated, the proposed swapping formulation shows excellent agreement with the data sets (quantified in terms of the percentage of absolute average relative deviation, %AARD) and better performance than the existing model formulations.