Comparison of the harm effects of accidental releases: Cryo-compressed hydrogen versus natural gas

Cryo-compressed storage of hydrogen is the only technology that meets 2015 DOE targets for volumetric and gravimetric efficiency for automobile applications. As promising hydrogen storage for commercial use, its hazards need investigation. One strategy for evaluating its hazard is comparing it with the existing natural gas storages. This paper studies the consequences of accidental releases from cryo-compressed hydrogen, compressed natural gas (CNG), and liquefied natural gas (LNG) storages for automobile applications. Both the non-flammable effects and flammable effects are evaluated, including cold, thermal, overpressure and missile effects. Results show that the cryo-compressed hydrogen releases always result in the worst consequences for non-flammable effects, but for flammable effects the worst consequences depend on the time of ignitions. Secondly, the longest lethal and harmful distances result from cryo-compressed hydrogen releases rather than CNG and LNG releases. Thirdly, from a pure harm perspective, CNG storage is safer than LNG storage in the event of catastrophic rupture but more dangerous in the case of leakages. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.