Prototype hydrogen source based on hydride forming materials

MANGIAROTTI F; GRACIELA BERTOLINO; ALBERTO BARUJ; GABRIEL MEYER

Moscu, Rusia

Simposio; MH 2010 - International symposium on metal hydrogen systems; 2010

MH

We have designed and constructed a prototype of a portable solid state hydrogen source. The prototype is based on the use of hydride forming materials for gas storage and compression. The device was primarily conceived to provide hydrogen to experiments outside the main hydrogen laboratory, like X-ray diffraction (XRD) measurements. We have selected LaNi5 as hydride because it provides an outlet pressure range between 3 bar and 60 bar for source temperatures between 22oC and 150oC. This alloy has additional advantages. It is fairly stable against cyclic degradation and, once degraded by cycling, it can be reconstituted by applying a simple thermal treatment. We have selected 316L stainless steel for the source vessel, considering that it has to stand elevated hydrogen pressures during its service life. The vessel design was the result of mechanical, heat transfer, weight and costs considerations. The initial mechanical and thermal models were tested and further optimized by using the finite element modeling. One of the main limitations, related to the low thermal conductivity of LaNi5 powder, was addressed by mixing the hydride with Cu wire. In this way, enhanced device sorption kinetics was obtained. We characterized the prototype experimentally using a dynamic absorption/desorption technique in a home-made volumetric equipment. In addition, we have successfully tested the prototype in specific XRD experiments.