Hydrate Formation and Dissociation Processes Investigated by NMR
Shuqiang Gao, Rice University, 5710 York Ave, Lubbock, TX 79414, Waylon House, Texas Tech, 2500 Broadway, Lubbock, TX 79409 and Walter G. Chapman, Rice University, 6100 Main St., Houston, TX 77096

Gas hydrates are ice-like structures in which water molecules, under pressure, form structures composed of nano-scale polyhedral cages surrounding gas molecule "guests" such as methane and ethane. The natural gas trapped in the naturally occurred gas hydrate deposits represents a potential source of energy many times all known natural gas reserves. Hydrates can form as well in undersea piping and above ground gas pipelines where they pose a major problem for gas/oil producers. Detailed understanding of hydrate melting and formation mechanisms on a molecular level is important for successfully tackling all hydrate challenges with accuracy and confidence.

Nuclear Magnetic Resonance (NMR) has been shown to be a powerful tool to non-invasively measure molecular level dynamic information. In this work, for the first time, we employ spin-spin relaxation times (T2) measurement of tetrahydrofuran (THF) in deuterium oxide (D2O) during the transient hydrate formation and dissociation processes, which dynamically reflect the changes of water molecular arrangements around the spin bearing THF molecules. Microscopic insights of the hydrate processes gained from this NMR investigation will contribute significantly to the fundamental understanding of hydrate mechanisms.

Extended Abstract Status: Not Uploaded

Nanoscale Systems: Water in Inhomogeneous Environments

The Preliminary Program for 2005 Annual Meeting (Cincinnati, OH)