Transformation of Methane Hydrate to Carbon Dioxide Hydrate: In Situ Raman Spectroscopic Observations

摘要

In this paper, we present experimental arguments for the guest replacement of methane hydrate with carbon dioxide using in situ Raman spectroscopy at high pressures. The surface shielding of carbon dioxide hydrate formed in the outer layer plays a key function of retarded dissociation of methane hydrate in the core. The water phase produced during the replacement reaction allows the reaction to proceed rapidly by enhancing diffusion of both methane and carbon dioxide, resulting in complete and relatively fast recovery of methane gas from methane hydrate. These results may strongly encourage further efforts in the study of guest stability of clathrate hydrate and may provide useful applications for future technologies.