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 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.

• 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/