초록 |
This study investigated the time-dependent kinetic selectivity of SF6 in the hydrate-based gas separation process thorough both experimental and computational approaches. The enclathrating and releasing behaviors of SF6 in SF6 + N2 hydrates were analyzed using in-situ Raman spectroscopy, gas chromatography, and micro-second molecular dynamics (MD) simulations. During hydrate formation, the growth pattern of the Raman peak for enclathrated SF6 was similar to that for enclathrated N2, and the SF6 composition in the hydrate phase was almost constant. Furthermore, the captured SF6/N2 ratio in the hydrate structure obtained from the MD simulation was almost constant during hydrate formation. These results demonstrated that there was no significant kinetic selectivity of SF6 during hydrate formation. In addition, the in-situ Raman spectra and MD simulation results demonstrated that SF6 was not kinetically selective during hydrate dissociation. These overall results will be helpful for determining the optimal operation time for the hydrate formation and dissociation process and thus for designing and operating the hydrate-based SF6 separation process. |