3-in-1 technique applied to mixed CH4:CO2 gas hydrates
The 3-in-1 method was used to study hydrate morphology, kinetics and phase equilibria of hydrates formed in gas-dominated systems containing pure CH4, pure CO2, and two CH4:CO2 mixtures (80:20 and 30:70 on a molar basis). This technique offered high resolution imaging and a tight control of pressure...
- Autores:
-
Ortiz Torres, Nathalia
- Tipo de recurso:
- Trabajo de grado de pregrado
- Fecha de publicación:
- 2019
- Institución:
- Universidad de los Andes
- Repositorio:
- Séneca: repositorio Uniandes
- Idioma:
- eng
- OAI Identifier:
- oai:repositorio.uniandes.edu.co:1992/45781
- Acceso en línea:
- http://hdl.handle.net/1992/45781
- Palabra clave:
- Hidratos de gas
Hidratos
Crecimiento de cristales
Ingeniería
- Rights
- openAccess
- License
- http://creativecommons.org/licenses/by-nc-nd/4.0/
Summary: | The 3-in-1 method was used to study hydrate morphology, kinetics and phase equilibria of hydrates formed in gas-dominated systems containing pure CH4, pure CO2, and two CH4:CO2 mixtures (80:20 and 30:70 on a molar basis). This technique offered high resolution imaging and a tight control of pressure and temperature. The same experimental temperatures were used for all gas compositions. Different pressures allowed to match subcoolings across mixtures, in the range of {delta}Tsub = 0.5 K to {delta}Tsub = 4.5. In addition, multiple driving forces were studied in a single experiment using temperature gradients across a single sample. Crystal morphology was found to be highly dependent on the CH4:CO2 molar ratio, and a higher dependence on the {delta}Tsub was observed for methane-rich hydrate morphology. The measured hydrate film growth rate increased with increasing CO2 content and increasing {delta}Tsub. Hydrate growth beyond the original droplet boundary ('halo') was observed for pure CO2 and the two mixtures, and it was found to be dependent on the CH4:CO2 molar ratio and {delta}Tsub. A stepwise dissociation was used to measured the H-L-V equilibrium temperature (THLV). The dissociation was carried out by setting a gradient along the slide, which allowed a close control of the H-L-V interface position. |
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