Abstract
We present modifications to a previously reported statistical thermodynamics model that facilitates the prediction of capillary pressure effects on hydrate equilibria in narrow pores. The model uses the Valderrama modification of the Patel and Teja Equation of State (VPT EoS) for fugacity calculations in fluid phases, while the hydrate phase is modeled using the solid solution theory of van der Waals and Platteeuw (1959), as implemented by Cole and Goodwin (1990). The Kihara model for spherical molecules is applied to calculate the potential function for hydrate-forming gases. To account for capillary pressure effects on phase fugacities, we apply a correction similar to the Poynting correction for saturated liquids. This correction can be applied to any model capable of predicting bulk (unconfined) hydrate phase equilibria. The only new parameter required is hydrate-liquid interfacial tension-values for which we have derived previously from experimental data. The model assumes cylindrical pores, although differs from the majority of existing literature models in how the curvature of the solid-liquid interface is considered; we assume a curvature of 2/r for growth and 1/r for dissociation, in accordance with accepted capillary theory. Model predictions are validated against previously published experimental hydrate dissociation data for binary CO2-H2O, CH4-H2O and ternary CH4-CO2-H2O systems, and newly reported data for CH4-H2O-CH4O (3.5 mass% methanol aqueous solutions representing the salinity of seawater) systems, confined to mesoporous silica glass. Good agreement between predictions and experimental data is observed.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Introductory overview: Hydrate knowledge development
- Scanning Electron Microscopy investigations of laboratory-grown gas clathrate hydrates formed from melting ice, and comparison to natural hydrates
- Dynamics of trimethylene oxide in a structure II clathrate hydrate
- The stability of methane hydrates in highly concentrated electrolyte solutions by differential scanning calorimetry and theoretical computation
- The effect of elevated methane pressure on methane hydrate dissociation
- Methane hydrate formation in partially water-saturated Ottawa sand
- Methanol—inhibitor or promoter of the formation of gas hydrates from deuterated ice?
- Investigating the performance of clathrate hydrate inhibitors using in situ Raman spectroscopy and differential scanning calorimetry
- Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate
- Experimental studies on the formation of porous gas hydrates
- Investigation of jet breakup and droplet size distribution of liquid CO2and water systems—implications for CO2hydrate formation for ocean carbon sequestration
- Measurement of clathrate hydrate precipitation from CO2solution by a nondestructive method
- Influence of water thermal history and overpressure on CO2-hydrate nucleation and morphology
- Growth-controlling processes of CO2gas hydrates
- Thermodynamic prediction of clathrate hydrate dissociation conditions in mesoporous media
- Modeling dynamic marine gas hydrate systems
- Late-stage, high-temperature processesing in the Allende meteorite: Record from Ca,Fe-rich silicate rims around dark inclusions
- Partitioning of Sr, Ba, Rb, Y, and LREE between alkali feldspar and peraluminous silicic magma
- Nondestructive three-dimensional element-concentration mapping of a Cs-doped partially molten granite by X-ray computed tomography using synchrotron radiation
- A theoretical study of structural factors correlated with 23Na NMR parameters
- Metamorphic formation of Sr-apatite and Sr-bearing monazite in a high-pressure rock from the Bohemian Massif
- Ultra-deep origin of garnet peridotite from the North Qaidam ultrahigh-pressure belt, Northern Tibetan Plateau, NW China
- Letter. Novel high-pressure behavior in chlorite: A synchrotron XRD study of clinochlore to 27 GPa
- Letter. Periodic precipitation pattern formation in hydrothermally treated metamict zircon
- A high pressure X-ray diffraction study of aragonite and the post-aragonite phase transition in CaCO3
Articles in the same Issue
- Introductory overview: Hydrate knowledge development
- Scanning Electron Microscopy investigations of laboratory-grown gas clathrate hydrates formed from melting ice, and comparison to natural hydrates
- Dynamics of trimethylene oxide in a structure II clathrate hydrate
- The stability of methane hydrates in highly concentrated electrolyte solutions by differential scanning calorimetry and theoretical computation
- The effect of elevated methane pressure on methane hydrate dissociation
- Methane hydrate formation in partially water-saturated Ottawa sand
- Methanol—inhibitor or promoter of the formation of gas hydrates from deuterated ice?
- Investigating the performance of clathrate hydrate inhibitors using in situ Raman spectroscopy and differential scanning calorimetry
- Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate
- Experimental studies on the formation of porous gas hydrates
- Investigation of jet breakup and droplet size distribution of liquid CO2and water systems—implications for CO2hydrate formation for ocean carbon sequestration
- Measurement of clathrate hydrate precipitation from CO2solution by a nondestructive method
- Influence of water thermal history and overpressure on CO2-hydrate nucleation and morphology
- Growth-controlling processes of CO2gas hydrates
- Thermodynamic prediction of clathrate hydrate dissociation conditions in mesoporous media
- Modeling dynamic marine gas hydrate systems
- Late-stage, high-temperature processesing in the Allende meteorite: Record from Ca,Fe-rich silicate rims around dark inclusions
- Partitioning of Sr, Ba, Rb, Y, and LREE between alkali feldspar and peraluminous silicic magma
- Nondestructive three-dimensional element-concentration mapping of a Cs-doped partially molten granite by X-ray computed tomography using synchrotron radiation
- A theoretical study of structural factors correlated with 23Na NMR parameters
- Metamorphic formation of Sr-apatite and Sr-bearing monazite in a high-pressure rock from the Bohemian Massif
- Ultra-deep origin of garnet peridotite from the North Qaidam ultrahigh-pressure belt, Northern Tibetan Plateau, NW China
- Letter. Novel high-pressure behavior in chlorite: A synchrotron XRD study of clinochlore to 27 GPa
- Letter. Periodic precipitation pattern formation in hydrothermally treated metamict zircon
- A high pressure X-ray diffraction study of aragonite and the post-aragonite phase transition in CaCO3