Metal hydride storage process

Several storage systems can be implemented, making up water splitting. The electrochemical NiOOH/MH metal hydride storage process has been implemented in a bipolar AlGaAs/Si cell [104],... 

The NiOOH/MH metal hydride storage process is near ideal for the AlGaAs/Si because of the excellent match of the storage and photocharging potentials. The electrochemical storage processes utilizes M H oxidation and nickel oxyhydroxide reduction ... 

One of the problems with early hydride systems was decrepitation of the alloy. Each time the metal hydride storage tank was recharged the particles would break down and eventually the particles became so small that they began to pass through the 5-p.m sintered metal filter which kept the hydride inside the tank. Addition of 0.5% manganese, which caused the decrepitation process to cease once the particles reached a size of about 10 p.m, solved this problem. 

Improvement in metal hydride hydrogen storage has been slow in achieving the targets needed for several applications. But slow, steady progress is foreseen as material processing in the nano-range improves the kinetics, thermodynamics, and capacity of the metal hydride systems so that they become acceptable for some applications perhaps for stationary systems. 

Sandrock, G.D. Snape, E. "Rechargeable Metal Hydrides. A New Concept in Hydrogen Storage, Processing and Handling". 

Another essential feature of the chemical hydride slurry approach is that hydride, oil, and water used in the system are recycled. The way in which the metal hydride/water reaction would be used in a closed loop system for the storage and transmission of hydrogen is illustrated in Figure 1. The process consists of the following major steps ... 

Figure 1. Simplified Process Diagram for Hydrogen Transmission/Storage with a Metal Hydride.

Zaluska A, Zaluski L, Strom-Olsen JO (2001). Structure, catalysis and atomic reactions on the nano-scale a systematic approach to metal hydrides for hydrogen storage. Applied Physics A Materials Science Processing 72(2) 157-165... 

Also, to provide completeness to this study a H2 storage medium is needed. It is beyond the scope of this study to evaluate all possible H2 storage systems. The incorporation of a metal hydride system provides one legitimate model for the assessment of downstream H2 distribution systems. By incorporating a MH storage and delivery system in this, two significant issues requiring additional research have been identified in the review process ... 

Application of SPD techniques to metal hydrides is a new field of research. Skripnyuk and Rabin were the first to use ECAP to improve the hydrogen storage properties of Mg-based alloys [254, 255]. The first study on ECAP-processed magnesium alloy ZK90 showed an improvement in sorption kinetics without loss of hydrogen capacity or change in thermodynamic parameters [254]. figure 4.12 shows comparable results for the Mg-Ni eutectic alloy [255]. 

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