1. Materials Innovations in an Emerging Hydrogen Economy Cocoa Beach FL 26 February 2008 Hollow Glass Microspheres (HGMS) Designed for Storing Hydrogen Delbert E. Day MO-SCI Corp Rolla MO & James E. Shelby New York State College of Ceramics Alfred University

2. OUTLINE Introduction What are HGMS and how are they made? Why use HGMS for hydrogen storage? Gas storage and release from HGMS Thermal release Photo-induced outgassing (release) Photo-induced release from soda lime glass doped with FeO, NiO or CoO Conclusions

3. HGMS Applications Commercially available –Paint filler, polymer/rubber filler, foam filler, oil well drilling mud, bowling balls, etc. Laser fusion targets --- H 2 D 2 –Strict specifications on size, shape, wall thickness, and surface smoothness (achieved internal pressure of 10,000 psi) Containers for hydrogen storage (Teitel-1977) Shelby and Hall

4. Why Use HGMS for Hydrogen Storage? Mechanically strong Light weight Environmentally friendly Low cost Reusable Chemically durable Non-toxic Commercially available High hydrogen mass density, 6 to 14 wt% Fire safe—non-explosiveUltra pure hydrogen

5. Manufacturing of HGMS Prepare precursor particles Gas-evolution (Blowing ) Melt & spheridize particles Collect & size Glass types: Soda Lime Borosilicate High Silica Heated tube or flame N 2, H 2 O,CO 2,SO 2

6. Manufacturing of HGMS Prepare precursor particles Gas-Evolution (Blowing) Melt and spheridize particles Collect and size Glass types:: Soda Lime Borosilicate High Silica Heated tube or flame N 2, H 2 O,CO 2,SO 2

7. Appearance of as-made HGMS made from doped amber soda lime glass 5 wt % FeO 5 wt % CoO Back scattered image (200X) Shelby, Raszewski, & Hall

8. Concepts of Gas Storage & Release Using HGMS Gas Filling StageGas Release H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 H2H2 Low Pressure-Ambient TemperatureHigh Pressure-High Temperature Gas

9. GLASSES USED TO MAKE HGMS Ave dia*Ave wall* Bulk density thickness g/cc Clear “soda lime” 131 2.30.41 Amber “soda lime” 38 1.9 0.46 Amber “soda lime” + 1 or 5 wt % FeO 60 1.3 0.25 “ “ NiO 133 2.8 0.25 “ “ CoO 62 0.9 0.19 * Microns Soda lime glass contained 9 wt % B 2 O 3 Sulfate blowing agent

10. Residual Gas Analyzer instrument used to measure hydrogen release from filled HGMS (10 to 90 mg) Spl in 6 mm tube Shelby and Hall

11. What is Photo – Induced Gas Release (Outgassing)? H2H2 H2H2 H2H2 H2 H2 H2H2 H2H2 H2H2 H2H2 250 W Infrared Light Bulb Hollow Glass Microspheres IR/Visible Radiation 800 – 2300 nm light is most effective Shelby & Hall

12. Comparison of photo-induced H 2 outgassing at 25 o C vs. thermally induced outgassing by heating at 150°C (soda lime HGMS containing 5 wt% FeO). Photo-induced @ 25 o C thermal—150 o C Shelby & Hall

13. Switch – like photo-induced H 2 outgassing for HGMS containing 5 wt% FeO. 5 minutes ON/OFF cycle Max release decreases with each cycle due to lower pressure in HGMS 15 seconds ON/OFF cycle Lamp on full time after 780 seconds

14. CoO is more effective than FeO in photo-induced release Rate of H 2 release increases with increasing concentration of CoO. 700 torr Temp. 25 0 C Effect of Dopant on Photo-induced H 2 Release Shelby & Hall

15. Photo-induced H 2 release from HGMS of different diameter (microns) 5 % CoO <50 100>x>50 >100 Lamp on Snyder, Wachtel, et.al.

16. Dependence of photo-induced release on fill pressure 5 % CoO 77,600 torr (1500psi) spl=10 mg 700 torr spl=90mg Lamp on Snyder, Wachtel, et.al.

17. H 2 retained in 5 wt% FeO HGMS after 5 weeks at 25 o C or 50°C. After 5 wks 97% retained at ~25°C and 92% at 50 o C Thermally outgassed at 25°C 5 wks Shelby & Hall

18. Conclusions Photo induced release offers many advantages for hydrogen storage >>fast response (10 to 20s) at ambient temperature >>release rate easily controlled >>no expected limit for on-off cycles Hydrogen retention > 90% after 5 wks at 50 o C (122 o F) HGMS have survived 5000 psi fill pressure (10wt% H 2 )

19. Acknowledgements We thank the Department of Energy (DOE), contract DE-FG36-05GO15007, for funding this work.