Hydrogen Storage in Gas Clathrate Hydrates: New Experimental Results for Selected Promoters

L.J. ROVETTO; A. SHARIATI; C.J. PETERS

Santiago de Compostela, Espana

Simposio; 24th European Symposium on Applied Thermodynamics; 2009

As a renewable energy source, hydrogen is a highly promising candidate. Significant progress has been obtained towards the energy economy during the last years. However, hydrogen storage remains a problem that has to be overcome in order to implement a hydrogen-based economy system. None of the current research areas on hydrogen storage materials has yet achieved the ultimate goals. The relatively new application of gas hydrates as hydrogen storage material is considered to be a promising solution. In this work, experimental results on the phase behaviour of the system THF+H2+H2O and the effect of the promoter concentration on the equilibrium conditions are reported. The phase boundary for the solid phase (hydrate or ice) were measured for THF concentrations from 0.49 up to 11.02 mole% ,in the temperature rage of 274 - 282 K and pressures up to 14.5 MPa. A maximum thermal stability was observed at concentrations of THF around 5-6 mole%. Other organic molecules were tested as potential H2-hydrate promoters at concentrations close to the stoichiometric value. The measured equilibrium conditions for hydrate stability gives the following promoting effect sequence: cyclohexanone < acetone < trimethylene oxide < 1,3-dioxolane < 2,5-dihydrofuran < tetrahydropyran < furan < tetrahydrofuran < cyclopentane.