Hydrogen storage systems based on hydride–graphite composites: computer simulation and experimental validation

Standardized hydrogen storage module with high utilization factor based on metal hydride-graphite composites

“…In contrast to the temperature signal that is at steady-state (Figure 4, bottom), the pressure signal does not exhibit a perfectly flat plateau. This behavior has been expected as pressure-concentration-isotherms of the pure material also show a sloping plateau [17]. Furthermore, from Figure 4, for absorption, the main fraction of hydrogen is absorbed at pressures between 10 and 15 bar and for desorption between 4 and 6.5 bar.…”

“…Furthermore, the kinetics of the material are fast, i.e. absorption and desorption proceed in the relevant temperature and pressure range in less than 30 s [16], and its hysteresis as well as plateau slope are moderate [9,17]. Figure 2 For absorption, a hydrogen supply pressure of 30 bar is assumed, as this corresponds to a reasonable pressure provided by an electrolyzer without a complementary compressor 7 .…”

“…Due to the utilization of MHC with a high thermal conductivity, the required homogeneous temperature and transformed fraction distribution can be achieved in tubes with an inner diameter of 21 mm . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 9 Table 1: Summary of properties for powder or MHC material as well as calculated design parameters (materials properties taken from [17]).…”

Open and closed metal hydride system for high thermal power applications: Preheating vehicle components

“…The endothermal desorption in reactor 2 (storage reactor) causes a temperature decrease which leads to an additional cooling power. Its value is a little smaller than the one of the heating power due to the smaller desorption enthalpy of C5® (ΔH = 28.4 kJ/mol H2 [30]). Nonetheless, this cooling power could probably be utilized for cooling purposes (e.g.…”

Mechanical stresses originating from metal hydride composites during cyclic hydrogenation

“…Before each hydrogenation experiment, a cyclic thermal treatment (100 C; 5/1.5 bar H 2 ; 4/1 h; 2-times) was carried out to activate the hydrogen absorbing alloy. The 39 mm MHC pellets were hydrogenated in a special test tank described in detail elsewhere [33]. In order to provide a sufficient hydrogen flow rate into the 39 mm MHC pellet via a hydrogen artery (sintered metal filter), the MHC pellets featured a cylindrical hole (6 mm) in the centre.…”