| A novel high-pressure visual cell was developed for the determination of clathrate hydrate phase equilibria. Experimentally, the compact hydrate apparatus was placed on the stage of an optical microscope for observation during warming runs to determine the hydrates' decomposition temperatures and pressures. The microscope enabled close visual examination and video recording of the hydrate cell's contents as it was heated. The onset of hydrate decomposition was noted by the initial formation of microscopic gas bubbles. These grew in size and increased in number as the decomposition temperature was reached and exceeded. Bubble formation at this level has not been previously reported by other researchers.; Some interesting behavior was noted on runs involving structure H hydrate-forming systems, corroborating the proposed concept of transition from structure I to structure H upon hydrate decomposition that was recently reported in the literature. The research examined various hydrate-forming systems involving methane and carbon dioxide, although the method developed can be used with any system of interest. |
