Two-dimensional dynamic analysis of metal hydride hydrogen energy storage conduction bed models

El-Osairy, M.; El-Osery, I.A.; Metwally, A.M.; Hassan, M.A.

doi:10.1016/0360-3199(93)90009-y

Cited by 9 publications

(6 citation statements)

References 5 publications

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“…3 Mass and volume of 10 kg hydrogen stored reversibly by 8 different methods, based on the best obtained reversible densities reported in the literature without considering the space or weight of the container. 29,[68][69][70][71][72][73] high gravimetric (9.19 wt.%) and volumetric (109 (g H 2 ) L À1 ) hydrogen density available from a compacted tablet. 23 Recently, research on Ca(NH 3 ) 8 Cl 8 has also shown promise for mobile applications, since the hydrogen density is as high as 9.78 wt.% and the release of ammonia is achieved at lower temperatures than that of Mg(NH 3 ) 6 Cl 2 , thereby reducing the energy needed to desorb the ammonia, but also the stability at 60 C. 2 The lower desorption temperature of Ca(NH 3 ) 8 Cl 8 results in a higher ammonia vapor pressure at room temperature (0.7 bar), but this is still an order of magnitude lower than that of liquid ammonia.…”

Section: Solid Storage Of Ammoniamentioning

confidence: 99%

Ammonia for hydrogen storage: challenges and opportunities

et al. 2008

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The possibility of using ammonia as a hydrogen carrier is discussed. Compared to other hydrogen storage materials, ammonia has the advantages of a high hydrogen density, a well-developed technology for synthesis and distribution, and easy catalytic decomposition. Compared to hydrocarbons and alcohols, it has the advantage that there is no CO 2 emission at the end user. The drawbacks are mainly the toxicity of liquid ammonia and the problems related to trace amounts of ammonia in the hydrogen after decomposition. Storage of ammonia in metal ammine salts is discussed, and it is shown that this maintains the high volumetric hydrogen density while alleviating the problems of handling the ammonia. Some of the remaining challenges for research in ammonia as a hydrogen carrier are outlined.

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Section: Solid Storage Of Ammoniamentioning

confidence: 99%

Ammonia for hydrogen storage: challenges and opportunities

et al. 2008

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“… a All data are based on the best-obtained reversible densities reported in the literature without considering the space occupied by the container. – …”

Section: Introductionmentioning

confidence: 99%

Indirect, Reversible High-Density Hydrogen Storage in Compact Metal Ammine Salts

et al. 2008

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The indirect hydrogen storage capabilities of Mg(NH 3) 6Cl 2, Ca(NH 3) 8Cl 2, Mn(NH 3) 6Cl 2, and Ni(NH 3) 6Cl 2 are investigated. All four metal ammine chlorides can be compacted to solid tablets with densities of at least 95% of the crystal density. This gives very high indirect hydrogen densities both gravimetrically and volumetrically. Upon heating, NH 3 is released from the salts, and by employing an appropriate catalyst, H 2 can be released corresponding to up to 9.78 wt % H and 0.116 kg H/L for the Ca(NH 3) 8Cl 2 salt. The NH 3 release from all four salts is investigated using temperature-programmed desorption employing different heating rates. The desorption is found mainly to be limited by heat transfer, indicating that the desorption kinetics are extremely fast for all steps. During desorption from solid tablets of Mg(NH 3) 6Cl 2, Mn(NH 3) 6Cl 2, and Ni(NH 3) 6Cl 2, nanoporous structures develop, which facilitates desorption from the interior of large, compact tablets. Density functional theory calculations reproduce trends in desorption enthalpies for the systems studied, and a mechanism in which individual chains of the ammines are released from the surface of the crystal is proposed to explain the fast absorption/desorption processes.

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“…As the temperature increases, the hydriding reaction of Na 3 AlH 6 to NaAlH 4 approaches its thermodynamic equilibrium at 6.0-6.8 MPa hydrogen pressure. The P e for 2 mol.% Ti(OBu n ) 4 catalyzed materials is 5.4 MPa [9]. Although the reaction rate increases with temperature, the capacity decreases as a result of decreasing thermodynamic driving force.…”

Section: Resultsmentioning

confidence: 96%

“…No kinetics model was reported to simulate transient hydriding rate and hydrogen absorption capacity of NaH+Al derived from NaAlH 4 . In this study, a solid/gas chemical kinetics model originally developed by El-Osery [6][7][8][9] to design conventional metal hydride systems was utilized. This model was adapted for use in the multi-step hydrogen absorption mechanisms of NaH+Al→NaAlH 4 .…”

Section: Introductionmentioning

confidence: 99%

Integrated Hydrogen Storage System Model

Hardy¹

2007

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Two-dimensional dynamic analysis of metal hydride hydrogen energy storage conduction bed models

Cited by 9 publications

References 5 publications

Ammonia for hydrogen storage: challenges and opportunities

Ammonia for hydrogen storage: challenges and opportunities

Indirect, Reversible High-Density Hydrogen Storage in Compact Metal Ammine Salts

Integrated Hydrogen Storage System Model

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