Navigating the Challenges of Zero-Carbon Ammonia in Maritime Shipping

ShipUniverse: Zero-Carbon Ammonia Fuel Overview
Key Point Details
Safety Concerns Ammonia’s toxicity and lack of established handling regulations pose significant safety challenges, particularly during refueling operations.
Economic Viability Higher costs and lower energy density compared to conventional fuels make ammonia less economically attractive at present.
Industry Adoption Limited adoption with 25 ammonia dual-fuel ships ordered globally as of 2024; projections indicate potential growth to one-third of bunker fueling by 2050.
Future Outlook Addressing safety and cost challenges through research and regulation is crucial for the successful integration of ammonia as a marine fuel.

The maritime industry is exploring zero-carbon ammonia as a potential alternative fuel to reduce its carbon footprint, which accounts for nearly 3% of global emissions. While ammonia offers the advantage of being carbon-free when produced from renewable hydrogen, its adoption faces significant cost and safety challenges.

Safety Concerns

Ammonia is highly toxic and poses risks such as acute poisoning and damage to the skin, eyes, and respiratory tract. The lack of established regulations and experience in handling ammonia on board ships constitutes major safety deterrents. Refueling operations, known as bunkering, present particular challenges due to the potential for leaks. A study by the Global Centre for Maritime Decarbonisation identified 400 risks associated with ammonia bunkering, which can be mitigated with measures such as emergency-release couplings to shut systems when a leak is detected. Developing detailed emergency response plans for ammonia spills is also crucial, as ammonia dissipates in air, making containment more complex than oil spills.

Economic Viability

The cost of powering ships with ammonia is currently two to four times higher than with conventional fuels. This is due to limited supply for the marine sector and ammonia’s energy density being about two-and-a-half times lower than traditional fuel. To travel the same distance, ships would need to carry more fuel or refuel more frequently, impacting operational efficiency. Additionally, ammonia engines require extra maintenance due to the fuel’s corrosive nature.

Industry Adoption

Despite these challenges, the industry is making strides toward adopting ammonia as a marine fuel. Globally, 25 ammonia dual-fuel ships have been ordered as of 2024, trailing a fleet of at least 722 LNG-fueled ships and 62 methanol-fueled ships. Only two smaller ammonia-fueled vessels are currently in service, including a tugboat in Japan. The American Bureau of Shipping forecasts that ammonia will account for about one-third of bunker fueling by 2050. However, companies like Rio Tinto are cautious, stating that they will not bring any product to market until they are 100% certain that all risks have been duly managed.

While zero-carbon ammonia presents a promising pathway for decarbonizing maritime shipping, addressing safety concerns and improving economic viability are essential for its widespread adoption. Ongoing research, regulatory development, and technological advancements will play critical roles in overcoming these challenges.