Metal Hydride Hydrogen Storage (Compression) Units Operating at Near-Atmospheric Pressure of the Feed H2

Inorganics. 2023. Vol. 11. No. 7. Article 290.

Tarasov Boris P., Arbuzov A., Mozhzhuhin S., Volodin A., Fursikov P., Lototskyy M.

Metal hydride (MH) hydrogen storage and compression systems with near-atmospheric H2 suction pressure are necessary for the utilization of the low-pressure H2 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 (H2 absorption at PL ≤ 1 atm) and discharge (H2 desorption at PH = 2–5 atm), which implies the provision of H2 equilibrium pressures Peq < PL at the available cooling temperature (TL = 15–20 ◦C) and, at the same time, Peq > PH when heated to TH = 90–150 ◦C. This work presents results of the development of such systems based on AB5 -type intermetallics characterized by Peq of 0.1–0.3 atm and 3–8 atm for H2 absorption at TL = 15 ◦C and H2 desorption at TH = 100 ◦C, respectively. The MH powders mixed with 1 wt.% of Ni-doped graphene-like material or expanded natural graphite for the improvement of H2 charge dynamics were loaded in a cylindrical container equipped with internal and external heat exchangers. The developed units with a capacity of about 1 Nm3 H2 were shown to exhibit H2 flow rates above 10 NL/min during H2 charge at ≤1 atm when cooled to ≤20 ◦C with cold water and H2 release at a pressure above 2 and 5 atm when heated to 90 and 120 ◦C with hot water and steam, respectively.

Keywords: Hydrogen storage, Metal hydrides, Hydrogen compression, low-pressure hydrogen