By: Franyi Sarmiento, Ph.D., Inspenet, July 5, 2022
As shipping moves forward in the transition from existing energy sources, the industry must proactively develop standard safeguards and control measures for the deployment of future fuels. To facilitate this, “Together in Safety,” a maritime industry safety consortium, initiated the “Future Fuels Risk Assessment,” a cross-industry study with nine partners to assess the potential operational risks of LNG, methanol, hydrogen and ammonia.
The collaborative study, which included a series of hazard identification workshops (HAZID) on a set of operational scenarios based on a standard tanker design, found that, of the four fuels examined, methanol presents the lowest overall risk, followed by LNG, hydrogen and ammonia.
HAZID risk ratings for fuels were assessed from a series of “What if” scenarios within four categories: navigation, external events, vessel operations and bunkering.
Methanol obtained the lowest risk ratings in scenarios related to navigation, such as loss of maneuverability, excessive movements or a blackout at sea, as well as in scenarios related to ship operations (other than bunkering), especially loading operations in case of damage to equipment or the ventilation mast and crew changes during ship handover.
Both LNG and hydrogen had nearly identical risk scores in all scenarios studied by the HAZID team, with none falling into the “intolerable risk” range. LNG performed better than hydrogen in an abandon ship navigation scenario due to loss of pressure control and loss of propulsion.
It should also be noted that there are well-established international regulations for the use of LNG as fuel on board ships, whereas for hydrogen no such regulations or guidance are available either for its use as fuel or for its storage in the marine environment. For the purposes of the study, the HAZID team has only considered cryogenic liquid hydrogen.
Across all fuels there are several medium risk ratings accepted as “tolerable,” but the study indicated that efforts should ensure that risks are reduced to “as low as reasonably achievable” (ALARP).
Ammonia scored a “broadly acceptable” risk score as a potential ignition source in the scenario of supporting tugboats or assisting third party vessels at sea. However, some risks of ammonia as a fuel are classified as high (or “intolerable”) in shipping scenarios such as grounding or collision resulting in a hull breach, loading operations in the event of damage to equipment or the ventilation mast, and leakage or loss of containment during bunkering.
To reduce these hazards to a medium or low risk rating, the study provides recommendations for the use of ammonia. These include safety equipment for mariners if there is a risk of gas pocket formation; specific emergency training for crew on fuel system safety devices and mitigation of damage to fuel system scenarios; and guidelines on fuel system designs that mitigate the risks of grounding or collision.
Partners in the “Future Fuels Risk Assessment” study include APM Terminals, Carnival Corp, Chevron, Euronav, Lloyd’s Register, Maersk, MSC Ship Management, Oil Companies International Marine Forum (OCIMF) and Shell.
This material from the MundoMarítimo portal was edited for clarity, style and length.
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