Analysis and experiment on dynamic prediction in magnesium hydride hydrolysis as hydrogen generator

In this paper, analysis and experimental verification for dynamic modeling of an acid-catalyzed magnesium hydride hydrolysis was used to predict the hydrogen generation yield, rate, and gravimetric hydrogen storage capacity. The result shows that the ratio citric acid to magnesium hydride, the geometric forms of MgH₂, and the water handling are crucial to this reaction, while the higher temperatures tend to have faster rates of reactions. Furthermore, the zero-order prediction gives a good result only at a relatively low citric acid to magnesium hydride ratio or low hydrolysis reaction rate. The reaction order is approximately one while the citric acid/magnesium hydride molar ratio remains high or the rate of reaction is high. Finally, considering the geometrical effect on the acid-catalyzed MgH2 hydrolysis, the validated Langmuir equation was used to successfully predict the dynamic hydrogen generation fairly well for most hydrolysis reaction rate.