Metal hydrides can store more hydrogen per unit volume than normal high pressure or cryogenic techniques. Little energy is required to store the hydrogen in the hydride, and high stability at room temperature ensures low losses over long storage periods. Safety features of metal hydride storage are favorable. Because of its low weight and high hydrogen storage densities, modified magnesium hydride offers the greatest potential for automotive storage of hydrogen. Experimental and analytical work in this program has been directed toward the optimization of this storage system. Due to the relative stability of MgH sub 2 , modifications of the MgMH/sub x/ (M = metal ion) have been made to decrease the dissociation temperature while retaining high hydrogen capacity. This parameter is crucial since vehicle exhaust will supply the thermal energy to dissociate the hydride in an automobile. System studies indicate that hydride dissociation temperature (T/sub D/) should be 200 exp 0 C to ensure uninterrupted fuel flow at all driving and idle conditions. From experimental data developed in this four task study, we conclude that alloys comprised of Mg, Cu and Ni have come closest to meeting the dissociation temperature goal. Small additions of rare-earth elements to the basic alloy also contribute to a reduction of T/sub D/. The best alloy developed in this program exhibits a T/sub D/ = 223 exp 0 C and a hydrogen capacity near four weight percent compared to a theoretical 7.65 percent for MgH sub 2 . That alloy has been characterized for dissociation temperature, hydrogen capacity, kinetics, and P-C-T relationships. Dissociation temperature, hydrogen capacity and material cost are reported for each alloy tested in this program. (ERA citation 05:027052)

  • Corporate Authors:

    Solar Turbines International

    2200 Pacific Highway
    San Diego, CA  United States  92101

    Department of Energy

    1000 Independence Avenue, SW
    Washington, DC  United States  20585
  • Authors:
    • Rohy, D A
    • Nachman, J F
    • Hammer, A N
    • Duffy, T E
  • Publication Date: 1979

Media Info

  • Pagination: 82 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00327024
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: EY-76-C-03-1167
  • Files: TRIS
  • Created Date: Feb 18 1981 12:00AM