The aim of this work is to model the thermal evolution inside a hydrate forming system which is submitted
to an imposed steady cooling. The study system is a cylindrical thin film of aqueous solution at 19 Mpa, the
methane is the hydrate forming molecule and it is assumed that methane is homogeneously dissolved in the
aqueous phase. The model in this work takes into account two factors involved in the hydrate
crystallization: 1) the stochastic nature of crystallization that causes sub-cooling and 2) the heat source term
due to the exothermic enthalpy of hydrate formation. The model equation is based on the resolution of the
continuity equation in terms of a heat balance. The crystallization of the methane hydrate occurs at
supercooling conditions (Tcryst < TF), besides, the heat released during crystallization interferes with the
imposed condition of steady decrease of temperature around the system. Thus, the inclusion of the heat
source term has to be considered in order to take into account the influence of crystallization. The rate of
heat released during the crystallization is governed by the probability of nucleation J(T ). The results
provided by the model equation subjected to boundary conditions allow depict the evolution of temperature
in the dispersed phase. The most singular point in the temperature–time curve is the onset time of hydrate
crystallization. Three time intervals characterize the temperature evolution during the steady cooling: (1)
linear cooling, (2) hydrate formation with a release of heat, (3) a last interval of steady cooling.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1382 |
| Date | 07 1900 |
| Creators | Avendaño-Gómez, Juan Ramón, García-Sánchez, Fernando, Gurrola, Dynora Vázquez |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
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