Automotive storage of hydrogen using modified magnesium hydrides. Final report, March 1976-March 1978

Technical Report · Mon Jan 01 00:00:00 EST 1979

DOI:https://doi.org/10.2172/5387727· OSTI ID:5387727

Rohy, D. A.; Nachman, J. F.; Hammer, A. N.; Duffy, T. E.

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/sup 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/sup 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.

• Research Organization: Solar Turbines International, San Diego, CA (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-03-1167
• OSTI ID: 5387727
• Report Number(s): SAN-1167-1
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AUTOMOBILES
HYDROGEN STORAGE
MAGNESIUM HYDRIDES
AUTOMOTIVE FUELS
COPPER ALLOYS
COPPER HYDRIDES
COST
DISSOCIATION
MAGNESIUM BASE ALLOYS
NICKEL ALLOYS
NICKEL HYDRIDES
SORPTIVE PROPERTIES
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
COPPER COMPOUNDS
FUELS
HYDRIDES
HYDROGEN COMPOUNDS
MAGNESIUM ALLOYS
MAGNESIUM COMPOUNDS
NICKEL COMPOUNDS
STORAGE
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
VEHICLES
080201* - Hydrogen- Chemisorption Storage
330800 - Emission Control- Alternative Fuels
080600 - Hydrogen- Industrial & Commercial Use- (-1989)
360105 - Metals & Alloys- Corrosion & Erosion