Hydrogen isotope gettering with yttrium metal

Hydrogen isotope gettering with yttrium metal

321 Journal of the Less-Common Metals, 74 (1980) 321 - 322 0 Efsevier Sequoia S.A., Lausanne - Printed in the Netherlands HYDROGEN STORAGE BY METAL ...

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321

Journal of the Less-Common Metals, 74 (1980) 321 - 322 0 Efsevier Sequoia S.A., Lausanne - Printed in the Netherlands

HYDROGEN STORAGE BY METAL HYDRIDES: A KEY TO MOBILE HYDROGEN TRANSPORTATION SYSTEMS*

ROGER E. BILLINGS Billings Energy Corporation,

Independence,

MO. 64057

(U.S.A.)

The application of hydrogen to vehicular storage systems has been tested in prototype systems over the past 4 years. Ref~emen~ in technology make possible the commercial application of hydrides for this purpose. Various design configurations and performance data are presented. The storage potential of metal hydrides compared with other storage mediums including compressed gas, cryogenic and electric storage batteries is considered. The long-term potential of fuel-cell-powered vehicles is also considered.

HYDROGEN ISOTOPE GEARING

WITH Y~RIUM

METAL*?

G. M. BEGUN, J. F. LAND and J. T. BELL Oak Ridge National

Laboratory,

Oak Ridge, Term. 37830

(U.S.A.)

Yttrium metal reacts exothermically with hydrogen to form a very stable hydride. Even at relatively low temperatures and pressures yttrium has excellent hydrogen sorption properties and the reversible recovery of the absorbed hydrogen can be accomplished by increasing the temperature and pumping off the dissolved gas. Thus, yttrium has been suggested for use as a getter material to remove tritium from fusion reactor systems. In fusion systems the partial pressure of tritium must be kept low in order to prevent tritium escaping to the surroundings, and the recovered tritium must be recycled to the reactor. Yttrium would be used to extract the tritium contained either in helium or liquid lithium which are proposed heat-exchanging fluids for the reactor. We measured the equilibrium hydrogen pressure as a function of concentration, temperature and isotope (Ha, Da, Ta). Temperatures were in the range 700 - 1000 “C. Equilibrium isotherms were plotted and relative *Abstract of a paper presented at the International Symposium on the Properties and Applications of Metal Hydrides, Colorado Springs, Colorado, U.S.A., April 7 - 11, 1980. ?J. Chem. Phys., 7.2 (1980) 2959 - 2966.

322

partial molal enthalpies and entropies were calculated for all three hydrogen isotopes. In the low concentration range our data followed Sievert’s law and Sievert’s constants were calculated. The isotope effects were measured and their direction and magnitude were compared with theory. This work was sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy under contract ~-7~05~ng-26 with the Union Carbide Corporation.

THE POTENTIAL FOR METAL HYDRIDES IN HEAT-P~P~G APPLICATIONS*

P. P. TURILLON Ergenics Division, MPD Technology N.J. 07481 (U.S.A.)

Corporation,

681 Lawlins Road, Wyckoff,

A survey of many industrial plants indicated that a large quantity of waste heat is rejected to the environment at temperatures in the range 50 - 70 “C (120 - 160 OF) while the same plants consume valuable fuel to produce steam at 100 - 110 “C (210 - 230 “F). The new technology of metal hydrides has opened up the possibility of designing heat pumps which would function in this temperature range and would be economical to operate since they have no moving parts. This paper describes the design of a prototype hydride heat pump built for this purpose. Calculations showed that one of the major factors influencing the rate of heat transfer was the quantity of water contained in the hydride beds. Thus the heat pump was designed to minimize the ratio of water to hydride in the heat exchangers. At the same time it was designed to be readily manufactured in large quantities. The heat exchangers consist of concentric tubes, the inner tube carrying hydrogen and the outer tube honing the heating water. Specially designed manifolds distribute the water and hydrogen to their respective tubes. The hydriding alloys are contained in patented capsules to improve heat transfer, to allow rapid flow of hydrogen and to prevent distortion of the tubes due to the expansion of the alloy during the hydriding reaction. Preliminary calculations of manufacturing and operating costs of the metal hydride heat pump indicate that it will recover waste heat contained in rejected hot water and will produce steam at costs which are competitive with other recovery methods. *Abstract of a paper presented at the International Symposium on the Properties and Applications of Metal Hydrides, Colorado Springs, Colorado, U.S.A., April 7 - 11, 1980.