1. FUNDAMENTAL SAFETY TESTING AND ANALYSIS OF HYDROGEN STORAGE MATERIALS & SYSTEMS
D. Anton, D. Mosher, W. Lohstroh, M. Fichtner,
N. Kuriyama, E. Akiba,
R. Chahine, D. Dedrick

2. Hydrogen Storage Compressed H2 Gas Cryogenic Liquid H2
5-10 ksi pressures in graphite fiber reinforced epoxy composite tanks
Cryogenic Liquid H2
Ambient pressure ultra-insulated containers with bleed off device
Compressed/Cryogenic H2
Cryogenic Liquid H2 in a high pressure tank to minimize boil-off
Adsorption
Utilizes physisorption on ultra-high surface area species. Currently used at LN2 temperatures.
Absorption
Utilizes chemisorption in metal, organic or complex compounds

3. Typical Chemisorption Reactions
LaNi5H6  LaNi5 + 3H2
Mg2NiH4  Mg2Ni + 2H2
Metal Hydrides
NaAlH4  1/3Na3AlH6 + 2/3Al + H2  NaH + Al + 3H2
Complex Metal Hydrides
2LiBH4 + MgH2  2LiH + MgB + 4H2
8LiH + 3Mg(NH2)2  Mg3N2 + 4Li2NH + 8H2
Destabilized Complex Metal Hydrides
AlH3  Al + 3/2H2
NH3BH3  BiNjHk + xH2
Chemical Hydrides

4. US-DoE Technical Targets
2007
2010
2015
Wt % H2 (Useable)
4.5 6 9
Vol. Cap. (kg H2/L)
0.036
0.045
.081
Cycles
500
1000
1500
Minimum rate (g/s)/kW
.02
Minimum/Maximum pressure (atm) [FC]
8/100
4/100
3/100
Minimum/Maximum ambient temperature (°C)
-20/50
-30/50
-40/60
Start time to full flow (s) 4
0.5
System fill time (min) 10 3
2.5
Safety
Meet or exceed applicable standards

5. Objective
To fundamentally understand the safety issues regarding solid state hydrogen storage systems through:
Development & implementation of internationally recognized standard testing techniques to quantitatively evaluate both materials and systems.
Determine the fundamental thermodynamics & chemical kinetics of environmental reactivity of hydrides.
Develop amelioration methods and systems to mitigate the risks of using these systems to acceptable levels.

6. Task 1: Standard Tests
DOT/UN Doc., Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, 3rd Revised Ed., ISBN , (1999).
Flammability
Flammability Test
Spontaneous Ignition
Burn Rate
Water Contact
Immersion
Surface Exposure
Water Drop
Water Injection
Mechanical
Impact
Expansion
Standard Test Method for Pressure and Rate of Pressure Rise for Combustible Dusts (ASTM E1226)
Pmax & (dP/Dt)max
Min. Exp. Conc.
Min. Ignition Energy
Min. Ignition Temp.
Min. Dust Layer Ignition Temp.

7. Task 2: Thermodynamics & Chemical Kinetics
Quantitative studies will be performed to understand the chemical kinetics and thermo-chemical release of these reactions with air, oxygen and water as both liquid and vapor as a function of temperature.

8. Task 3: Risk Mitigation
System risk analyses will be performed and methods of mitigating these risks including exposure to air and humidity will be investigated. No
Mitigation
With
Mitigation

9. Task 4: Prototype System Testing
Evaluation tests on risk mitigations strategies will be performed on sub-scale prototype storage systems to validate their efficacy.

10. Materials Test Plan NaAlH4+2%TiCl3 LiH+MgNH2 Mg2NiH4 LaNi5H6
2LiBH4+MgH2
NH3BH3
Activated Carbon
AlH3
Materials Prep Plan
Use Particle Size & Packing
Discharge State
Fully Charged
Partially Discharged
Fully Discharged

11. UTC 1st Prototype 1kg H2 Storage System
316 SS tubing for ParaTherm MR oil
4% dense aluminum foam
with 50% dense Ti catalyzed
NaAlH4 powder
316 SS liner
316 sintered SS filter
316 SS end closure to facilitate loading and inspection
One end closed carbon fiber composite containment
Rated to 1500psi
Under DoE sponsorship, UTRC is designing and fabricating the first hydrogen storage system based on an alanate formulation having 1 kg H2 storage capacity.
Utilizing alanate compositions as the hydrogen storage media requires many new heat, mass transfer and manufacturing techniques to be employed
Novel design concepts and methods such as the Convex Hull approach are being used in this liquid/solid heat exchange application to rapidly obtain optimal design and trade factors.

12. Burn Rate Test
Partially Discharged CCH#0-33
0 sec.
2.97
6.90
11.09

13. Water Drop Test
Partially Discharged CCH#0-33
0 sec.
0.11
0.12
0.15

14. Water Drip
Partially Discharged CCH#0-33
0 sec.
0.14
0.17
30.03

15. Flammability Test Results (DOT/UN) Class 4.3, Packing Group II

16. Air Exposure Test Partially Discharged CCH#0-33 0:00 min. 24:05 80oC
25:10 smoke observed
26:55 fire
34:15 max fire

17. Gasoline Burn Rate
0 sec.
0.03
0.75
0.88

18. Dust Explosion Test Results (ASTM E1226, E1515, E2019 & E1491)
Test Materials
Reference Materials
NaAlH4
NaH+Al
Pitt. Seam Coal Dust
Lycopodium Spores
Pmax bar-g
11.9
8.9
7.3
7.4
Rmax bar/s
3202
1200
426
511
Kst bar-m/s
869
326
124
139
Dust Class
St-3
St-1
MEC g/m3
140 90 65 30
MIE mJ
<7
110 17
Tc oC
137.5
584
430
Pmax = maximum explosion pressure, Rmax = pressure rise maximum, Kst = maximum scaled rate of pressure rise,
MEC = minimum explosive concentration, MEI = minimum spark ignition energy, Tc = minimum dust cloud ignition temperature

19. Communication
A WEB site will be established to communicate finding and results to the general public as expeditiously as possible.

20. Conclusion
The risks associated with manufacturing, handling, utilization and disposal of solid state hydrides needs to be quantitatively identified.
A thorough risk assessment of solid state hydrogen storage materials and systems needs to be performed.
Engineering risk mitigations strategies need to be identified and tested to bring the risks to tolerable levels for commercial application.