Hydrogen clathrate hydrate

In fact, more recent detailed studies of H2-THF clathrate hydrate directly contradict the findings of Lee et al. [20]. Strobel et al. [21] similarly utilized volumetric measurements in conjunction with Raman and NMR data for the binary system of H2-THF. They concluded that small cavities can only accommodate single H2 molecules, and that, irrespective of initial aqueous THF concentration and/or formation conditions, large cavities are always fully occupied by THF. They reported, therefore, that a maximum hydrogen content of around 1 mass% was possible for pressures less than 60 MPa, a value considerably lower than that claimed by Lee et al. [20]. The result of such contradictory findings is that the true phase behavior of binary H2-TH F hydrates remains to be identified through future studies on the topic. 

In another study carried out in 2007, Anderson et al. [23] experimentally determined the phase behavior of the system H2-THF-H2O as a function of aqueous THF concentration within a temperature range of 260-290 K and at pressures up to 45 MPa. This is a wider range of temperatures and pressures than in Rovetto et al. s study on the same system. Similar to the findings of Rovetto etal. [22], they found that H2-THF clathrates showed maximum thermal stability at the stoichiometric value of 5.56mol% initial THF concentration. 

In order to investigate Lee et al. s [20] claims about the hydrogen content of clathrates formed from THF concentrations below the eutectic composition (approximately 1.0mol% at 1 atm), Anderson et al. [23] experimentally prepared 

Additionally, molecules like propane have also been investigated [25]. The experimental results indicate that the hydrate formation pressures of hydrogen methane and hydrogen + propane gas mixtures were higher than those for pure methane and pure propane. 

With the goal of overcoming the problem of the occupation of the vacant cages of structure II hydrates by promoter molecules, Duarte et al. [31] proposed to increase 

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Inerbaev, T.M. Belosludov, V.R. Belosludov, R.V. Sluiter, M. Kawazoe, Y. (2006). Dynamics and equation of state of hydrogen clathrate hydrate as a function of cage occupation. Computational Materials Science, 36 (1-2), 229-233. 

Lokshin, K.A. Zhao, Y. (2006). Fast synthesis method and phase diagram of hydrogen clathrate hydrate. App. Phys. Lett., 88, 131909. 

Figure 3.3 Pressure-temperature diagram of hydrogen clathrate hydrate formation with different promoters [22].

The theoretical developments for hydrogen storage in molecular clathrates have been discussed extensively by Struzhkin et al. [1]. They explained that the complete theoretical description of hydrogen clathrate hydrates is usually based on a combination of different techniques including density functional theory (DFT) [34], molecular dynamicss (MD) [35], and similar approaches. 

Possible stmctures of hydrogen clathrate hydrates are refined at high pressures Co and sT. 

Frankcombe, T.J., Kroes, G.-J. Molecular dynamics simulations of type-sll hydrogen clathrate hydrate close to equilibrium conditions. J. Phys. Chem. C 111, 13044 (2007)... 

One of the most interesting topics at high pressures is application of hydrogen containing clathrate hydrates. Since the discovery of hydrogen clathrate hydrate. 

Hydrogen Occupation Ratio to Water (H2/H2O) in Hydrogen Clathrate Hydrate with Promoter at 250K and at Various Pressures (MPa) and Acetone Occupancies. No Occupation Ratio is Given to an... 

K. Katsumasa, K. Koga, and H. Tanaka, /. Chem. Phys., 127, 044509 (2007). On the Thermodynamic Stability of Hydrogen Clathrate Hydrates. 

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