THE PROPERTIES AND SOME APPLICATIONS OF THE HYDRIDE HYDROGEN-COMPRESSION ALLOY (CAMMCU)(NIAL)5ZR0.05

A new rare earth-nickel based alloy (CaMmCu)(NiAl)5Zr0.05 for the first stage hydride hydrogen compression in the production of high pressure supra-pure hydrogen from the hydrogen containing industrial gases and two double-stage multi-function units were developed. The experiences on using substitutional elements Cu, Ca, Al and alloying clement Zr to modify the properties of the mischmetal-nickel based hydrogen storage alloy MmNi5 (Mm stands for Ce-rich mischmetal), were employed for this purpose. In this paper the thermodynamic properties and two successful applications of this alloy are reported. Experimental results showed that the alloy is satisfactory for hydride hydrogen compression, with fast hydriding and dehydriding velocities, long cycle life, easy activation and large compression ratio. Two purification-compression units have been operated successfully for two years to produce supra-pure hydrogen from electrolytic hydrogen and the feed gas of synthetic ammonia production respectively.