Clean Technology 2011
R.V. Belosludov, H. Mizuseki, O.S. Subbotin, V.R. Belosludov, Y. Kawazoe
Institute for Materials Research, Tohoku University, JP
hydrogen, methane, propane, storage, clathrate hydrate, phase diagram, modelling
The possible formation of hydrogen hydrate, a class of inclusion compounds consisting of water and hydrogen as host and guest molecules, respectively, with different structures by adding various guest molecules suggests the practical feasibility of the binary hydrate as a hydrogen storage candidate. Thus, it is important to study the phase diagram of multi-component clathrate hydrates in detail which is still a challenging task due to their complexity. Theoretical approaches can be useful for understanding the thermodynamic properties of the binary hydrate and they can support the experimental exploration of novel hydrogen storage materials based on clathrate hydrates. Original approach accounting for multiple cage occupancy, host lattice relaxation, and the description of the quantum nature of guest behavior has been used for estimation the thermodynamic properties of pure hydrogen and binary X+H2 hydrates with the possibility of multiple filling of cavities by guest (X) molecules. The thermodynamic conditions of hydrate formation at equilibrium of the guest gas phase with ice have been determined. The hydrogen storage content in hydrates is estimated in wide range of p-T regions. The method is general and can apply to the various non-stoichiometric inclusion compounds with weak guest-host interactions.