Hydrogen Safety Panel, Safety Knowledge Tools, and First Responder Training Resources 

Owner/operators of chemical processing and petroleum refining sites often ask whether unconfined hydrogen vapor cloud explosions (VCEs) can actually occur. This question normally arises during the course of a consequence-based facility siting study (FSS) or a quantitative risk assessment (QRA). While it is generally recognized that a hydrogen release within a process enclosure could lead to an explosion, the potential for an external hydrogen release to cause a VCE is not as widely recognized and is often questioned.

VIII.8  Hydrogen Safety Panel and Hydrogen Safety Knowledge Tools

AS THE WORLD SEEKS TO IDENTIFY alternative energy sources, hydrogen-powered fuel cells offer a broad range of benefits for the environment, the economy, and energy security. Hydrogen fuel cells have the potential to replace the internal combustion engine and to provide power in a wide range of stationary and portable applications.

Quenching limits of hydrogen diffusion flames on small burners were observed. Four burner types,with diameters as small as 8 m, were considered: pinhole burners, curved-wall pinhole burners, tubeburners, and leaky fittings. In terms of mass flow rate, hydrogen had a lower quenching limit and a higherblowoff limit than either methane or propane. Hydrogen flames at their quenching limits were the weakest