Numerical analysis and performance assessment of metal hydride based hydrogen storage systems

This paper presents a detailed analysis of low-temperature metal hydride-based hydrogen storage systems by means of a 0-dimensional model previously developed by the authors. In the first part of this work the model is applied to simulate experimental systems described in the literature, where the absorption and desorption of hydrogen under constant-pressure conditions are studied. The numerically evaluated time evolution of several key parameters (such as hydrogen mass flow, temperature and pressure) is reported and its accordance with experimental results is discussed, in order to identify the model strengths and limits, and its validity scope. The model is then used as a tool to predict the performance of metal hydride hydrogen storage devices operating in FC-based energy systems. This is accomplished by analyzing the system transient response to a stepwise increase in FC load, and therefore in hydrogen mass flow rate, starting from a zero-flow initial condition.