Simulation of hydride heat pump operation

Fedorov, Eugene

doi:10.1016/s0360-3199(98)00138-4

Cited by 23 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Metal hydrides are a hot topic of discussion among the modern scientific community worldwide because they are used for storage and transport of hydrogen as well as for use in heat pumps as a cold energy supply [1][2][3][4] and hydrogen generator [5,6]. Hydrogen is considered clean energy with a large combustion value that can be used in internal combustion engines or fuel cells.…”

Section: Introductionmentioning

confidence: 99%

Chemical equilibrium analysis for hydrolysis of magnesium hydride to generate hydrogen

Hiraki

Hiroi

Akashi

et al. 2012

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

Magnesium hydride is a promising hydrogen source because of its high mass density of hydrogen, 15.2%, when it is hydrolyzed; MgH 2 + 2H 2 O = Mg(OH) 2 + 2H 2 + 277 kJ. However, a magnesium hydroxide, Mg(OH) 2 , layer forms rapidly on the surface of the unreacted MgH 2 as the pH increases, hindering further reaction. The purpose of this study is to find acids that could effectively accelerate the reaction by using a chemical equilibrium analysis where the relationships of pH to concentration of ionized Mg were calculated. For the best performing acid, the calculated and measured relationships were compared, and the effects of acid concentration on hydrogen release were measured. The analysis revealed that citric acid and ethylenediamine-tetraacetic acid were good buffering agents. The calculated and measured relationships between pH and concentration of ionized Mg were in good accord. Hydrogen release improved considerably in a relatively dilute citric acid solution instead of pure distilled water. The maximum amount of hydrogen generated was 1.7  10 3 cm 3 ·g -1 at STP after 30 min. We estimated the exact concentration of citric acid solution for complete MgH 2 hydrolysis by a chemical equilibrium analysis method.

show abstract