Static and dynamic characterization of metal hydride tanks for energy management applications

Abstract

In this paper, the dynamic and static characterization of commercial metal hydride tanks is developed based on black box modelling. The objective is to determine the thermodynamic parameters of the hydride, such as enthalpy and entropy, and then to perform an energy management of this hydrogen storage system coupled to a fuel cell generator. Therefore, for this study, a specific test bench was developed around two hydride tanks. The hydrogen temperature and pressure were measured as a function of time and used to evaluate the thermal energy produced and consumed, as well as the amount of hydrogen, stored and released, during the absorption and desorption process respectively. The analysis of the results allowed the determination of a number of parameters such as the maximum reversible hydrogen storage capacity, which was 100 [g] for each tank with a relative capacity of 0.8 [%], the equilibrium pressure between 1 and 4 [bar] for both processes (absorption/desorption) as well as the evaluation of the hysteresis. The black-box approach makes this characterization method suitable for any solid-state hydrogen storage system, regardless of metal hydride type, geometrical shape, and tank size.