Metal Hydride Hydrogen Storage (Compression) Units Operating at Near-Atmospheric Pressure of the Feed H-2

Metal hydride (MH) hydrogen storage and compression systems with near-atmospheric H-2 suction pressure are necessary for the utilization of the low-pressure H-2 produced by solid oxide electrolyzers or released as a byproduct of chemical industries. Such systems should provide reasonably high productivity in the modes of both charge (H-2 absorption at P-L & LE; 1 atm) and discharge (H-2 desorption at P-H = 2-5 atm), which implies the provision of H-2 equilibrium pressures Peq < P-L at the available cooling temperature (T-L = 15-20 & DEG;C) and, at the same time, Peq > P-H when heated to T-H = 90-150 & DEG;C. This work presents results of the development of such systems based on AB(5)-type intermetallics characterized by Peq of 0.1-0.3 atm and 3-8 atm for H-2 absorption at T-L = 15 & DEG;C and H-2 desorption at T-H = 100 & DEG;C, respectively. The MH powders mixed with 1 wt.% of Ni-doped graphene-like material or expanded natural graphite for the improvement of H-2 charge dynamics were loaded in a cylindrical container equipped with internal and external heat exchangers. The developed units with a capacity of about 1 Nm(3) H-2 were shown to exhibit H-2 flow rates above 10 NL/min during H-2 charge at & LE;1 atm when cooled to & LE;20 & DEG;C with cold water and H-2 release at a pressure above 2 and 5 atm when heated to 90 and 120 & DEG;C with hot water and steam, respectively.