Effect of pressure on the carbon dioxide hydrate-water interfacial free energy along its dissociation line

Abstract

We investigate the effect of pressure on the carbon dioxide (CO${}_2$) hydrate-water interfacial free energy along its dissociation line using advanced computer simulation techniques. In previous works, we have determined the interfacial energy of the hydrate at $400\text{bar}$ using the TIP4P/ice and TraPPE molecular models for water and CO${}_2$, respectively, in combination with two different extensions of the Mold Integration technique [J. Chem. Phys. 141, 134709 (2014)]. Results obtained from computer simulation, $29(2)$ and $30(2){\text{mJ/m}}^2$, are found to be in excellent agreement with the only two measurements that exist in the literature, $28(6){\text{mJ/m}}^2$ determined by Uchida et al. [J. Phys. Chem. B 106, 8202 (2002)] and $30(3){\text{mJ/m}}^2$ by Anderson et al. [J. Phys. Chem. B 107, 3507 (2002)]. Since the experiments do not allow to obtain the variation of the interfacial energy along the dissociation line of the hydrate, we extend our previous studies to quantify the effect of pressure on the interfacial energy at different pressures. Our results suggest that there exists a correlation between the interfacial free energy values and the pressure, i.e., it decreases with the pressure between $100$ and $1000\text{bar}$. We expect that the combination of reliable molecular models and advanced simulation techniques could help to improve our knowledge of the thermodynamic parameters that control the interfacial free energy of hydrates from a molecular perspective.

7 pages, 4 figures

References in corpus (4)

• Accurate determination of crystal structures based on averaged local bond order parameters
• The mold integration method for the calculation of the crystal-fluid interfacial free energy from simulations
• Interfacial Free Energy as the Key to the Pressure-Induced Deceleration of Ice Nucleation
• Simulation of the carbon dioxide hydrate-water interfacial energy

Cited by in corpus (5)

• Homogeneous nucleation rate of carbon dioxide hydrate formation under experimental condition from Seeding simulations
• Simulation of the THF hydrate-water interfacial free energy from computer simulation
• Rotationally invariant local bond order parameters for accurate determination of hydrate structures
• Unveiling the CO2 Hydrate Phase Diagram from Computer Simulation: Locating the Hydrate-Liquid-Vapor Coexistence and its Upper Quadruple Point
• Prediction of the three-phase coexistence line of the ethane hydrate from molecular simulation