Thermodynamics of clathrate hydrates

Lunine, J.I., Stephenson, D.J. (1985). Thermodynamics of Clathrate Hydrate at Low and High Pressures with Application to the Outer Solar System. Astrophys. J. Suppl. Ser. 58,493-531. 

Lunine, J. I., Stevenson, D. J. (1985) Thermodynamics of clathrate hydrate at low and high pressures with application to the outer solar system. Astrophys. J. Suppl., 58, 493-531. 

Kang, S.-P. Lee, H. (2001). Enthalpies of dissociation of clathrate hydrates of carbon dioxide, nitrogen, (carbon dioxide + nitrogen), and (carbon dioxide + nitrogen + tetrahydrofuran). J. Chem. Thermodynamics, 33 (5), 513-521. 

Structure identification and relative cage occupancies. The hydration number and relative cage occupation for pure components and guests were measured by Sum et al. (1997), Uchida et al. (1999), and Wilson et al. (2002). Raman guest spectra of clathrate hydrates have been measured for the three known hydrate crystal structures si, sll, and sH. Long (1994) previously measured the kinetic phenomena for THF hydrate. Thermodynamic sl/sll structural transitions have been studied for binary hydrate systems (Subramanian et al., 2000 Schicks et al., 2006). 

H. Tanaka and K. Kiyohara, The thermodynamic stability of clathrate hydrate. II. Simultaneous occupation of larger and smaller cages , J. Chem. Phys. 98 (1993) 8110. 

SOME STRUCTURAL AND THERMODYNAMIC STUDIES OF CLATHRATE HYDRATES... 

B. Thermodynamic Variables and Ensembles for the Equilibrium of Clathrate Hydrates... 

VII. Application to Thermodynamic Stability of Clathrate Hydrates A. Chemical Potential of Ices and Empty Clathrate Hydrates... 

Thermodynamic properties of clathrate hydrates have been calculated by the van der Waals and Platteeuw (vdWP) theory [16]. It has been applied to predicting... 

Let us begin with a system specified by (7 (v, / g, K 7) each indicating the number of water molecules, the number of guest molecules, the volume, and the temperature. Then, the appropriate thermodynamic potential is the Helmholtz free energy, A. The infinitesimal change in the free energy of clathrate hydrate system is written as... 

The chemical potential difference is tabulated in Table III [17,18]. There are small but nonmegligible differences depending on both the method and the pair potential. Two distinctive features are noteworthy. CS-II is more stable than CS-I irrelevant as to whether the anharmonic free energy is taken into account for the TIP4P potential (all the properties are calculated for clathrate hydrates with this potential unless otherwise mentioned) [52]. This is also true for most of the other pair potential of water such as SPC/E [53]. The chemical potential difference is negative for most of the potential but it is positive for the CC potential [54] and other potentials with the same functional form, which is favorable to observe a hydration structure around a hydrophobic solute but is inappropriate to evaluate the thermodynamic stability of clathrate hydrates. 

It is highly desirable to establish a relationship between reduction of the dissociation pressure and the efficiency as hydrogen storage in a wide range of pressure with varying composition of a promoter species. To this end, we should find a simple way to evaluate the thermodynamic stability of clathrate hydrates and its cage occupancy from intermolecular interactions currently available under a fixed occupancy of a promoter guest elaborated in Section III.D. Since the chemical potential of water is written as... 

Apart from the crystalline solids of clathrate hydrates, some cage structures in aqueous solutions around hydrophobic solutes have been observed by computer simulation [80-84], Therefore, it is important to investigate how the water-water interaction, and the tetrahedral hydrogen-bonded structure, is connected with the formation of clathrate hydrate structure when discussing the thermodynamic and structural properties of these aqueous solutions. 

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