Existing natural gas networks for 100% hydrogen transport: a case study in Europe

Hydrogen transportation via dedicated pipelines or repurposed existing natural gas (NG) grids is one of the most reliable and cost-efficient means of delivering hydrogen over long distances. However, due to embrittlement effects and ease of leakage, further research is needed to fully replace the natural gas in these assets. This study evaluates the tolerance of four API 5L carbon steel (grades X42, X52, X60 and X70) as well as the tightness and compatibility of different components and equipment (valves, pressure regulator, cartridge filter and turbine gas meter) of the existing high-pressure gas grid (16-80 bar) for 100% H 2 . Different tests were performed to analyze the effects of hydrogen on materials, components and equipment at the most common transportation pressure (80 bar). No embrittlement or other kind of damage was detected on C-ring, CT-WOL and 4pb specimens after 2500 h of exposure to 100% H 2 at 80 bar. All valves remained tight for the duration of the test, with just minor hydrogen losses due to hydrogen leakage through the body of the valves. Finally, no apparent damage was found on the different parts of the valves, pressure regulator, cartridge filter and turbine gas meter components after their exposure to hydrogen.