Progress for Reversible Metal Hydride Hydrogen Storage Systems
by Ned Stetson
Texaco Ovonic Hydrogen Systems, LLC

Steady progress continues on the development of standards for reversible metal hydride hydrogen storage systems. These systems are fast becoming the method of choice for storing hydrogen in portable fuel cell applications. One of their key advantages is that the bulk of the hydrogen is bound within the metal hydride compound, resulting in a compact, low-pressure system. As these systems become commercialized and are introduced into the marketplace, there is a need for industry standards to ensure safe design and to enhance their acceptability. This report reviews some recent progress in this area.

The International Standards Organization (ISO) is currently releasing ISO/CD 16111 Transportable Gas Storage Devices – Hydrogen Absorbed in Reversible Metal Hydride for comment. This document has been developed over the last two years by working group 10 under the ISO technical committee 197 for Hydrogen Technologies. The working group roster includes experts from North America, South America, Asia and Europe. The scope of this document includes all metal hydride hydrogen storage systems that are intended to be mobile, i.e. not fixed in stationary installations, excluding systems intended for permanent mounting on motor vehicles. It includes design considerations and qualification testing. For further information contact your national ISO/TC 197 representative, which for the USA the administrator is Ms. Debbie Angerman (dangerman@cganet.com) of the Compressed Gas Association.

In 2002 the Compressed Gas Association (CGA) formed a new ad hoc technical committee called the Metal Hydride and Alternate Hydrogen Fuel Technology Committee. The formation of this committee was in recognition that the use of hydrogen in fuel-type applications had needs that differ from the traditional industrial use of hydrogen. Since its formation the committee has been very active and has generated sufficient interest that the CGA has made it a permanent committee. The committee was also renamed to the Hydrogen Fuel Technology Committee, to better represent the full scope of activities the committee is involved with. To date the committee has been responsible for the publication of three new CGA documents, two concerning metal hydride hydrogen storage systems: CGA H-1 Service Conditions for Portable, Reversible Metal Hydride Systems and CGA H-2 Guidelines for the Classification and Labelling of Hydrogen Storage Systems with Hydrogen Absorbed in Reversible Metal Hydrides. The third publication is CGA PS-17, a position statement on Underground Installation of Liquid Hydrogen Storage Tanks. The committee is currently working on several new standards, including one for portable metal hydride hydrogen storage systems, one for refill systems for metal hydride systems and one on terminology used in hydrogen fuel technologies. For further information, contact Chris Carnahan (ccarnahan@cganet.com) or visit the CGA website at www.cganet.com.