2. Hydrogen Energy
(2) R&D Necessary for the Development of Hydrogen Stations
Hydrogen facilities including refueling stations are subject to control under the High Pressure Gas Safety Act and other applicable laws because high-pressure, flammable hydrogen gas is handled at these facilities. These laws, however, do not have provisions for effectively controlling applications of advanced technologies such as hydrogen facilities. In this regard, revisions to these laws as well as development of technical standards are strongly desired for ensuring safe operation of hydrogen facilities and smooth construction of hydrogen infrastructure. In fiscal 2003, JPEC started research on safe operation of hydrogen stations for the purpose of identifying the safety requirements that hydrogen stations should comply with. JPEC is currently focusing on the following major technical issues:
①Review of the General High-Pressure Gas Safety Regulation and other applicable regulations
JPEC has been reviewing the General High-Pressure Gas Safety Regulation and other regulations applicable to hydrogen stations. Specifically, research is conducted for the hydrogen fueling standards (i.e. Fueling Protocol), the periodic safety inspection standards, the regulations on safety distances, and the standards regarding allowable maximum temperatures and safety valves of hydrogen containers for trailers. JPEC has been making strenuous efforts for integrating research results into voluntary consensus standards (JPEC-S).
②Studies on the metallic materials applicable to hydrogen stations
Mechanical properties of metals exposed to high-pressure hydrogen are altered in a phenomenon called hydrogen embrittlement. Under the High Pressure Gas Safety Act, the metallic materials applicable to hydrogen stations are limited. JPEC has been working together with organizations concerned in conducting various performance evaluation tests for understanding properties of stainless steels and low-alloy steels with the aim of elucidating the conditions under which these metals can be used safely. It is expected that the results of these tests and studies will be helpful in revising the current regulations, increasing applicable metallic materials, and easing the conditions for use of metallic materials.
③Research on the technical standards applicable to CFRP composite pressure vessels for hydrogen storage
Hydrogen stations are equipped with pressure vessels for bulk high-pressure hydrogen storage. Steel vessels have been used for this purpose, but they will be increasingly replaced by CFRP composite vessels. These are carbon fiber reinforced plastic pressure vessels with an aluminum/plastic liner. However, use of CFRP vessels has not been spread due to the lack of standards regarding their technical aspects. Thus, JPEC has been analyzing basic data obtained by various performance evaluation tests for the purpose of developing technical standards necessary for the design, manufacturing and inspections of the CFRP composite pressure vessels for hydrogen storage.