New pragmatic strategies for optimizing Kihara potential parameters used in van der Waals-Platteeuw hydrate model

The study aims to tune the Kihara potential parameters to construct a robust and accurate van der Waals-Platteeuw (vdW-P) model. A new procedure was developed for fitting the Kihara potential parameters in the vdW-P hydrate model using the experimental hydrate equilibrium data for both pure gases and binary-gas mixtures, considering the differences between hydrate structures I and II. To ensure reliability of the optimization results, a large database, with more than 3000 hydrate equilibrium data, was compiled for pure hydrate-forming gases and their binaries, measured over a wide temperature and pressure range. The Kihara potential parameters, optimized using the new fitting procedure, not only performed well in modeling pure-gas hydrates but also provided more accurate predictions on the hydrate equilibria of gas mixtures. Thus, the vdW-P hydrate model can be employed to detect the hydrate structure transition and cage occupancy behaviors when used in conjunction with the newly fitted Kihara potential parameters. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study aims to tune the Kihara potential parameters to establish a robust and accurate van der Waals-Platteeuw (vdW-P) model for gas hydrates. Parameters were optimized using experimental data, resulting in improved modeling of pure-gas hydrates and more accurate predictions for gas mixtures in hydrate equilibria. The vdW-P hydrate model combined with the newly fitted Kihara potential parameters can effectively detect hydrate structure transitions and cage occupancy behaviors.