Energy Research
Photo-enhanced Hydrogen Diffusion Through Glass Microspheres: Development of Microsphere Production for Hydrogen Storage

James Shelby and Matthew Hall, NYSCC at Alfred University
Robert Doremus, Rensselaer Polytechnic Institute
July 2004 - December 2005

Objectives of Study
Previous research supported by CEER has proven the validity of photo-enhanced hydrogen diffusion through glasses doped with optical activators and have been presented at two major conferences on glass science. Glass composition, dopant identity, wavelength of light which causes this effect, etc. have been determined. Development of a working gas storage device now requires the production of hollow glass microspheres (HGMS) of the appropriate, non-commercial compositions, which will be the primary objective of the proposed study. Once these HGMS have been produced, they will be used to determine the kinetic parameters which control the design of a working hydrogen generator.

Experimental Approach
Hollow glass microspheres will be produced using the sol-gel method. The starting material is a solution containing all of the compounds needed to prepare a desired glass. Droplets of the solution are injected into a heated column. The outer layer of the droplets is the first to dry, resulting in the formation of a “skin”. As in making popcorn, this skin expands as the water contained within the droplets converts to steam.If an appropriate thermal treatment is employed, the particles maintain their spherical geometry and form HGMS. Development of this process will consist of creation of an appropriate solution stable precursor solution containing the necessary components for forming HGMS and construction and testing of an apparatus for producing HGMS. Once HGMS are available, the kinetics of filling/release of hydrogen will be determined using a PVT method coupled with light as an activating energy source.

Expected Results
This study will provide the information and a facility needed to produce HGMS (a significant addition to our research facilities) and with adequate samples of HGMS to study kinetics of filling and outgassing of HGMS. The kinetic study will provide the data needed to design an operational hydrogen generator. Earlier proposals for major funding have been criticized for the lack of absolute proof that this process will work with real HGMS. Results of the proposed study will provide us with the needed “reduction to practice” needed to patent the hydrogen storage device and to convince potential funding agencies and automobile manufacturers of the viability of this technique. Ultimately, our work should lead to a revolutionary new method for storing, transporting, and delivering hydrogen on demand. The Hydrogen Research Laboratory at Savannah River has indicated their desire to become a partner with us for high pressure hydrogen work and for future proposals based on this concept. Praxair, Corning, Inc. and others have also expressed interest in commercialization of this technology once sufficient proof of the concept has been produced.

Results of this study will aid in the advancement of energy technology and in improving the market for a renewable energy source. The use of hydrogen has the potential to drastically alter the transportation industry, radically reduce smog, and save hundreds of billions of dollars in cost of imported oil.

Objectives of Proposed Research
(A) Develop the technique needed to produce hollow glass microspheres of the glass/dopant combination found in our previous work to provide optimal photo-enhanced hydrogen diffusion.

(B) Produce HGMS in adequate amounts for further testing of filling and outgassing kinetics.

(C) Measure filling and outgassing kinetics needed to design an operational hydrogen storage and delivery device.

Hypothesis to be Tested
Storage of hydrogen as a gas encased in hollow glass microspheres can be carried out in a manner which allows rapid release of hydrogen by photo-enhanced diffusion to meet the demands of fuel cells and other devices using hydrogen as a fuel. Testing of this hypothesis requires production of hollow glass microspheres in order to build a working hydrogen generator.

Importance of Research
Development of fuel cells for transportation and other applications depends of the availability of a reliable, light weight, easily transported, and very safe source of hydrogen [1-5]. Many industrial processes also depend upon the availability of hydrogen in an easily transported form. Systems utilizing the storage of hydrogen in hollow glass microspheres can meet these requirements [6-8]. Development of these systems has been limited by the relatively slow rate of release of hydrogen from glass microspheres, which has, until now, been altered by controlling the temperature of the microspheres [8-10].

A completely new phenomenon based on photo-enhanced diffusion of hydrogen in glass has been discovered by the principal investigator and co-workers [11-16]. Application of this phenomenon to glass microspheres for storage of hydrogen can provide the enabling technology for replacement of traditional methods for storing and transporting hydrogen in high pressure containers or at cryogenic temperatures with lighter, cheaper, safer technology. Use of hydrogen for combustion or in fuel cells will drastically alter the transportation industry, radically reduce smog, and save many billions of dollars in cost of imported oil [1-5].

Application of photo-enhanced diffusion to storage and transport of hydrogen in HGMS has advanced to the point where proof of concept using actual HGMS is necessary to further the progress toward a working hydrogen generator. Since the glass/dopant combination needed for this mechanism to occur is not available as commercial HGMS, it is necessary to develop the process for producing the HGMS in our laboratory. Once this process is in place, we can produce adequate supplies of HGMS to design and construct a working model of a hydrogen generator. This study will address these factors, seeking to optimize the HGMS production process and to produce adequate amounts of materials to carry out the kinetic measurements needed to design the hydrogen generator.

Expected Results/Benefits
Results of this study will provide us with the information needed to determine the feasibility for application of the photo-enhanced diffusion effect for the commercialization of hydrogen storage in HGMS. Demonstration of the photo-enhanced diffusion effect for actual HGMS will conclusively prove that this method for hydrogen storage is a viable candidate for development of a commercial hydrogen generator. It is possible that we will then pursue the possibility of establishing a small business to continue this work, or find an industrial partner for the production of a hydrogen generator. We have already been approached by the Savannah River Hydrogen Facility regarding partnering in this effort, by MoSci, Corp. in Rolla, MO, which is a producer of specialized solid and hollow glass microspheres, and by Techneglas, Corp, which is a major glass manufacturing company. Corning, Inc. has also expressed an interest in further development of this technology if it can be demonstrated in HGMS. Praxair has been in contact with us regarding our studies and is interested in the potential for this process for their industrial hydrogen division and is following our work. In each case, the demonstration of the photo-enhanced diffusion effect in HGMS is considered to be a major step toward forming a working partnership to promote this concept.

From an environmental perspective, replacement of fossil fuels with hydrogen can lead to a major reduction in the generation of pollutants and provide a path by which current non-renewable fuels can be replaced by a renewable one. Since hydrogen can be produced from water, and the combustion of hydrogen produces water, the use of hydrogen as a fuel results in a water-hydrogen-water cycle which is the ultimate in a renewable energy source. The results of this study will aid in both the advancement of energy technology and in improving the market for a renewable energy source.

Facilities
Design and construction of a facility for the production of HGMS is a primary goal of this study. Once operational, this facility will be a major addition to the research capabilities of Alfred University and will allow pursuit of funding in several other areas, including several potential research possibilities in biomaterials, in photonics, and in other applications of glasses.

References
1. J. M. Ogden, “Developing an infrastructure for hydrogen vehicles: a Southern California case study,” International J. of Hydrogen Energy, 24, 709-730 (1999).

2. R. N. Schock, G. D. Berry, J. R. Smith & G. D. Rambach, “Hydrogen as a near-term transportation fuel,” Preprint, UCRL-JC-121355, Lawrence Livermore National Laboratory, Livermore, CA (1995).

3. J. R. Smith & S. Aceves, “Hybrid vehicle system studies and optimized hydrogen engine design,” UCRL-JC-120151, Lawrence Livermore National Laboratory, Livermore, CA (1995).

4. J. M. Ogden, “Prospects for building a hydrogen energy infrastructure,” Ann. Rev. Energy Environ., 24, 227-79 (1999). (major review article)

5. M. Steinbugler & R. H. Williams, “Beyond combustion: fuel cell cars for the 21st century,” Forum Appl. Res. Public Policy, 13, 102-7 (1998).

6. G. D. Rambach & C. Hendricks, “Hydrogen transport and storage in engineered glass microspheres,” Proc. 1996 USDOE Hydrogen Program Rev. Meet., Miami, 765-72, National Renew. Energy Lab. (1996).

7. G. D. Rambach, “Hydrogen transport and storage in engineered glass microspheres,” Proc. of the 6th Annual U.S. Hydrogen Meeting, 163-72 (1995) (reprint without full details of source indicated)

8. RJTA website, “Microcavity processes for hydrogen storage, transport, and supply systems,” http://www.smlassociates.com/glassspheres.htm

9. P. C. Souers, I. Moen, R. O. Lindahl & R. T. Tsugawa, “Permeation eccentricities of He, Ne, and D-T in soda-lime glass microbubbles,” J. Am. Ceram. Soc., 61, 42-46 (1978).

10. R. L. Woerner, B. W. Weinstein, I. Moen, J. Rittmann, “Working strengths and D-T fill procedures for glass microsphere laser fusion targets. UCRL-82728, Lawrence Livermore National Laboratory, Livermore, CA (1979).

11. J. E. Shelby & B. E. Kenyon, “Glass Membrane for Controlled Diffusion of Gases,” #6,231,642, May 15, 2001 (assigned to Praxair)

12. B. E. Kenyon, “Gas Solubility and Accelerated Diffusion in Glasses and Melts,” M.S. Thesis, Alfred University, 1998. (This thesis reports the discovery of photo-enhanced diffusion of gases in glasses.)

13. D. B. Rapp & J. E. Shelby, “Photo-Induced Hydrogen Outgassing of Glass,” presented at University Conference on Glass Science, RPI, Troy, NY, August, 2003.

14. D. B. Rapp & J. E. Shelby, “Photo-Induced Hydrogen Outgassing of Glass,” to be published, J. Non-Cryst. Solids, 2004.

15. D. B. Rapp & J. E. Shelby, “Photo-Induced Hydrogen Outgassing of Glass,” presented at Am. Ceram. Soc. Fall Meeting of the Glass and Optical Materials Division, Corning, NY, October, 2003.

16. D. B. Rapp & J. E. Shelby, “Photo-Induced Hydrogen Outgassing of Glass: An Enabling Technology for a Hydrogen Economy,” to be presented at Am. Ceram. Soc. Annual Meeting, April, 2004 (invited presentation).

17. J. E. Shelby, HANDBOOK OF GAS DIFFUSION IN SOLIDS AND MELTS, ASM International, Materials Park, OH, 1996. (This book by the principal investigator contains a complete review of gas diffusion in glasses and a thorough discussion of the experimental methods to be used in this study. All of the relevant sources are cited in this work.)

18. C. E. Lord, “Alkali borosilicate glasses as precursors for nanoporous membranes,” Ph. D. Thesis, Alfred University, 1998.