Experimental study on hydrogen storage properties of Li-Mg-N-H based tank

Cylindrical lab-scale tank based on 98.0 g of the Mg(NH2)(2)-2LiH-0.07KOH compacts was designed. Hydrogen storage properties of the tank, including bed temperature, hydrogen pressure and flow rate in the hydrogen absorption and desorption process were investigated under a variety of conditions. In the hydrogen absorption process of which the applied hydrogen pressure is 6.0 MPa, the central temperature of the hydride bed increases obviously from 453 K to 524 K. Furthermore, the increase of the applied hydrogen pressure can lead to greater changes in the bed temperature. The hydrogen desorption process exhibits 3 stages under the constant flow rate mode, and the hydrogen desorption of Mg(NH2)(2)-2LiH-0.07KOH mainly carries out at stage II accompanied with a significant temperature drop. As the flow rate increases, the endothermic dehydrogenation of the hydride degrades the bed temperature to a lower value, and the amount of hydrogen released also decreases at this stage. The results indicate that an efficient improvement of the heat transfer property for the Li-Mg-N-H based tank is needed to improve its sorption behavior. (C) 2014 Elsevier B. V. All rights reserved.