Hydrate phase equilibria in porous media: effect of pore size and salinity

✍ Scribed by Kasper K. Østergaard; Ross Anderson; Maria Llamedo; Bahman Tohidi

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 653 KB
• Volume: 14
• Category: Article
• ISSN: 0954-4879
• DOI: 10.1046/j.1365-3121.2002.00433.x

✦ Synopsis

ABSTRACT Considering the ever‐increasing importance of marine gas hydrates, it is crucial to gain a better understanding of clathrate formation and decomposition in porous media. It is well established that, due to capillary effects, small‐diameter pores – similar to those found in natural sediments – act to inhibit hydrate stability. However, accurate data constraining these effects are still lacking. Here, we present experimental methane clathrate dissociation data for 3.5 mass% methanol aqueous solutions in confined silica glass pores of narrow distribution (30.6, 15.8, and 9.2 nm mean diameters). These data have been used to validate a thermodynamic model for clathrate stability porous media. Experimental data show a marked improvement on literature data – which we attribute to the experimental and interpretative methods used – and are in good agreement with the model predictions. Results suggest that mass transfer of inhibitors (methanol) and dissolved gas during clathrate formation/dissociation within the porous network plays an important role in controlling gas hydrate equilibria.