The Port of Amsterdam has requested DNV to carry out a study for the purpose of making a comparison of safety distances for bunkering of alternative fuels with those for the bunkering of LNG.
ccording to the study, bunkering of gaseous hydrogen is “not likely to be used for shipping, in view of the low energy density and the relatively low bunkering flow rates that are mentioned in literature.”
This makes the time required for bunkering unrealistically high in order to satisfy the energy demand
However, there is a party that claims that gaseous hydrogen can be bunkered at 3,000 kg/h without problems being caused by the rapid heating of the storage system by adiabatic compression. This claim is not further examined in terms of feasibility.
Nevertheless, if such bunkering flow rates are feasible, it is helpful to understand the safety distances because then the bunkering duration is more realistic.
This does not mean to say that bunkering seagoing vessels with this high flow rate will be more likely, considering the low energy density and the required bunkering volumes
Location-specific individual risk/external safety distances
The results for the location-specific individual risk show that the external safety distances for bunkering of methanol and gaseous hydrogen are much smaller than those for LNG.
What is more, for refrigerated ammonia and liquid hydrogen, the safety distances are similar to those for LNG, and for pressurised ammonia, the distances are about three times as large due to the generation of a large toxic cloud in the event of a hose rupture.
Furthermore, according to the study, if a composite hose is used instead of a metal hose for bunkering operations, the risk will decrease because of the lower failure frequency for the rupture scenario of a composite hose.
Focus areas visualise where without additional measures, people are insufficiently protected indoors against the consequences of accidents involving hazardous substances. In the new Environmental and Planning Act 2022, a distinction will be made between three types of focus areas:
- Fire focus area;
- Explosion focus area;
- Toxic cloud focus area.
The results show that the focus areas for ammonia are by far the largest because of the large toxic effect. The focus areas for bunkering LNG are in the same order of magnitude as those for liquid hydrogen. The focus areas for bunkering methanol and gaseous hydrogen are 3 to 6 times smaller compared to LNG
the study finds.
According to current insights for calculating the risks of gaseous hydrogen, explosion focus areas do not really apply to bunkering of gaseous hydrogen.