The optimal design of hydride tanks is a major technological issue for the rapid development of this technology. In this paper, a two-dimensional model of a closed metal hydrogen reactor is presented. The temperature and the pressure temporal evolutions within the reactor as a function of time are reported. In order to determine the parameters to optimize a fast kinetic and optimal heat exchange, the impact of the supply pressure, the porosity and the dynamic viscosity have been studied. The results show that the effect of these parameters are key-factors for an optimized tank design. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.