ABS director – fuels & technology, global sustainability, René Sejer Laursen details why ammonia is being considered as a viable alternative fuel, and how it can be used safely.
Zero Carbon Fuels
Over the next decade, zero-carbon fuels such as ammonia and hydrogen have the potential to significantly lower the carbon footprint of shipping, particularly when using well-to-wake emissions criteria.
Of these two zero-carbon fuels, ammonia has the advantages of a simpler distribution, storage, and bunkering supply chain and is better suited to existing and emerging technologies for propulsion and power generation. Further, ammonia’s production does not require the use of scarce waste biogenic biomass as is the case for renewable carbon-based fuels such as bioethanol, bioLNG, and biodiesel.
Safety Concerns
In common with all alternative fuels, ammonia comes with caveats that must be addressed for it to be used safely. While ammonia’s toxicity raises concerns about its impact on assets and people, looked at in a broader context, ammonia has many similarities to other alternative marine fuels proposed for shipping.
In everyday operations, ammonia could be considered a ‘business as usual’ fuel, like methanol or liquified petroleum gas (LPG). The principal issue is understanding the potential impact on the crew from vapor escape and putting in place the systems and procedures to mitigate these risks.
Regulatory Measures
Widely traded, ammonia is a long-established cargo, and its handling requirements are covered by the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code). The handling of ammonia as a marine fuel is specified in the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code) under alternative fuels.
What is new for vessel design and operations is the delivery of ammonia from the bunker tanks to the engine room and propulsion system. The main issue to address is toxicity in the event of vapor or liquid escapes and human exposure. A system to handle escaped ammonia or an absorber system to tackle ammonia vapor will be mandatory in ammonia-fuelled ships.
Solutions At Hand
As interest in ammonia continues to grow as a solution to reduce carbon emissions from shipping, shipowners are increasingly seeking advice and support to safely integrate this emerging fuel into future vessel designs.
Among the work carried out by ABS is analysis and scenario creation for engine rooms, bunker systems, ventilation outlets, vent mast position, and vapor dispersion across different vessel types. The technology solutions proposed will vary from ship to ship but may typically include vapor absorbers and dispersion analyzers in addition to a vent mast. ABS is currently developing procedures for crew training and protection, designed to be used by engineering personnel for use in the safe management of ammonia and best practices in the event of a vapor release.
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Source: Riviera
