Thermal analysis of methane hydrate formation in a high-pressure reactor packed with porous SiC foam ceramics

摘要

The porous SiC foam ceramic (SFC) packings were recently demonstrated capable of enhancing methane hydrate formation in the hydrate-based separation technologies, while the heat transfer analysis is one of the key requirements for effective implementation of this technology. In this study, the evolution of thermal resistance during hydrate formation was obtained based on hydration heat and gas consumption in experiments, while the effects of the packings' properties (e.g. quantity, porosity, materials, stacking patterns) on the overall and local thermal resistances were predicted by the conducive heat transfer models. The overall tendency predicted by the model agreed with the experimental data. Results clearly indicated that the SFC packings could maintain the reaction system at a low thermal resistance for a longer time under relative low driving force. It also highlighted the role of the stacking patterns of SFC packings on heat transfer. The overall thermal resistance was reduced by about 39% after rotation of the SFC packings. When the SFC packings were stacked parallel to the reactor bottom, the composites formed by packings and hydrates was the main resistance for heat transfer which accounted for 30-50% of the overall thermal resistance. However, the contribution of this portion was only 13-25% if the SFC packings were stacked perpendicular to the reactor bottom. Overall results from this study were beneficial for better understanding where the main heat transfer resistance was from and how it varied against the packings' properties when employing the foam packings for enhancing gas hydrate formation.