We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
In situ Raman and <sup>13</sup>C NMR spectroscopic analysis of gas hydrates formed in confined water: application to natural gas capture.
- Authors
Juwoon Park; Kyuchul Shin; Jong-Won Lee; Huen Lee; Yutaek Seo
- Abstract
This study investigates the formation characteristics of gas hydrate from bulk water as well as dispersed water in silica gel and dry water particles when they are exposed to natural gas. The inclusion process of methane, ethane, and propane molecules in hydrate cages were observed with in situ Raman spectroscopy, and the resulting cage occupancies were estimated from 13C NMR spectra. A high-pressure autoclave was used to monitor the formation process to determine hydrate onset time, initial growth rate, and conversion ratio. The obtained data from Raman spectra and gas consumption profiles suggested that hydrate formed within less than 20 min when the temperature is sufficiently lower than the hydrate equilibrium condition at a given pressure. Methane molecules started to occupy the small cages of structure II, but about 6 min later ethane and propane were also included in hydrate cages. 13C NMR spectroscopy confirms that only 23% of large cages of structure II are occupied by methane molecules when hydrate formed from dispersed water in silica gel, which was much less than 68% from dry water. These results suggest that the dispersion of water in silica gel and dry water would enhance the formation process by increasing gas-to-water ratio, although the composition of hydrate phase may vary depending on the formation condition. However the formation of hydrate in silica gel and dry water still provide an effective option to capture the natural gas without using complex rotating machineries.
- Subjects
GAS hydrates; NATURAL gas; NUCLEAR magnetic resonance spectroscopy; SILICA gel; RAMAN spectra
- Publication
Canadian Journal of Chemistry, 2015, Vol 93, Issue 9, p1035
- ISSN
0008-4042
- Publication type
Article
- DOI
10.1139/cjc-2014-0536