Hydrogen safety, state of the art, perspectives, risk assessment, and engineering solutions

The final goal of realizing the hydrogen economy requires also the solution of safety issues related to the properties of hydrogen and to the technologies for storage, transport, and utilization. The hydrogen transport has been treated with an engineering approach. Hydrogen transportation via pipelines or by road and tunnel is analyzed and the respective risk evaluated. Risk acceptability criteria for transportation in tunnel adopted in some countries are compared. Transport scenarios strictly related to hydrogen release from liquid hydrogen were analyzed and their characteristics were computed by implemented DG-QRAM method. Finally, the main safety strategies to mitigate the effects of hydrogen release and the minimum safety requirements to be taken into account are suggested. Safety engineering issues such as alignment and the length of road section or tunnel, expected traffic volume, and the relevant percentage of dangerous goods vehicles should be taken into account in order to mitigate the effects of hydrogen transport.