Sandia researchers at the Combustion Research Facility for years have studied and modeled the intricate workings of the combustion engine and, more recently, hydrogen behavior and its effects on materials and engine components, San Marchi said. The knowledge gained by Sandia's work on the physical behavior of hydrogen and risks associated with hydrogen fuels provided the scientific basis to revise the separation distances in the NFPA 2 code for hydrogen installations.
H2 fueling stations can be as safe as or safer than gasoline stations
Under the previous code, virtually no hydrogen fuel cell stations could be sited at existing stations. The reason, said San Marchi, is simple: Those codes were developed via an "expert opinion-based process" and not the risk-informed process developed by Sandia researchers and now used in the code. The previous code was developed for flammable gases in an industrial setting, which carries different risks compared to hydrogen fuel at a fueling station.
"The distances set forth in the code, therefore, were much larger than we now know they need to be," San Marchi said. The risk metric used to develop the new NFPA code, he added, was that the stations accepting hydrogen fuel needed to be proven as safe as or safer than gasoline-only stations.
Some gas stations still may not be able to accept hydrogen under the new code because gas station lot sizes vary greatly, and many smaller sites particularly those in dense, urban areas cannot be properly configured, he said.
"Certain smaller gas stations, especially those in cities, have unusual shapes that aren't going to accommodate the right separation distances," San Marchi said. For example, he said, the required distance between a high-pressure tank carrying hydrogen and the property boundary would be too great for a "skinny" sta
|Contact: Mike Janes|
DOE/Sandia National Laboratories