Closed Loop Cycling Device for Hydride Forming Materials Characterization

M. S. GRINBERG; B. A. TALAGAÑIS; P. ARNEODO LAROCHETTE; A. BARUJ; F. J. CASTRO; G. MEYER

Hawaii

Congreso; MH2006 International Symposium on Metal-Hydrogen Systems; 2006

For most practical applications, hydride forming materials should stand a large number of hydrogen absorption/desorption cycles during their lifetime. So, the study of the change of technological properties of materials under cycling is a necessary test before industrial application. Cycling devices are usually based on open loop configurations involving a high purity hydrogen source and an exhaust system. The main drawbacks of such configurations are an important hydrogen waste and a potential concern with gas purity. Here we present a novel, fully automated, device designed to perform cycling tests in a closed loop configuration. The equipment allows us to detect variations in the storage capacity of the material and in the hydrogen absorption/desorption kinetics. The setup involves three parts: a) a reactor where the sample to be studied is loaded, b) an intermediate volume and c) a hydrogen supply/sink. These parts are connected to each other via electrically actuated valves. The main novelty of our device consists in the use of LaNi5 as the hydrogen supply/sink when is heated/cooled during cycling. The LaNi5 is mixed with 15% Cu powder in order to improve the thermal transference, reducing the time of an absorption/desorption cycle. In this way, gas economy and gas purity are insured. The available cycling pressure range is 5 - 55 bar, with a minimum cycle time of 4 min. The temperature of the reactor can be set between room temperature and 300oC.