Ship Fuels: Ammonia - Is the Juice Worth the Squeeze?

As the maritime industry grapples with stringent regulations to reduce greenhouse gas emissions, ammonia emerges as a potential darling alternative fuel, offering a solution devoid of carbon emissions during combustion. However, it’s highly toxic and corrosive and must be stored at below-zero temperatures. Given the massive pros and cons of the substance, the industry is asking, "Is the juice worth the squeeze?"

Ammonia plays a crucial role in various industries, primarily in producing fertilizers. About 80 percent of ammonia globally is used to make fertilizers such as urea, ammonium nitrate and ammonium sulfate, which are essential for modern agriculture. Ammonia is also a precursor to many chemicals including the production of nitric acid for explosives, plastics and dyes.

Most ammonia production today relies on the Haber-Bosch process, developed in the early 20th century, to synthesize ammonia from nitrogen and hydrogen gases. This process is highly carbon-intensive and contributes significantly to global CO2 emissions. 

However, there’s growing interest in sustainable production methods such as green ammonia, which is produced using renewable energy sources like wind, solar power, nuclear and electrochemical synthesis, directly producing ammonia from nitrogen and water using electricity.

Ammonia as a marine fuel offers several advantages and disadvantages. On the positive side, it doesn’t produce CO2 during combustion, making it a potential zero-carbon fuel when produced from renewable sources. It also has a relatively high energy density compared to other alternative fuels, making it arguably suitable for long voyages.

However, it’s also highly toxic and corrosive, requiring stringent safety measures for storage and handling. While it eliminates CO2 emissions, ammonia combustion can produce NOx and N2O (nitrous oxide, aka laughing gas), which need effective management to prevent environmental harm. 

Significant investments are also required to modify existing ammonia bunkering and storage infrastructure.

Fuel for Thought

Recognizing that ammonia is one of the most traded global commodities, Liam Blackmore, Decarbonization Coordinator at Lloyd's Register, emphasizes the need for safety and regulatory frameworks for its adoption as a marine fuel.  

"Current global ammonia production is around 180 million tons per year, mostly for fertilizers,” he explains. “However, forecasts indicate marine fuel demand could reach 688 million tons of ammonia annually by 2050. It should also be noted there are currently no marine type-approved ammonia engines on the market. However, IMO interim guidelines will be developed this year at the 10th session of Carriage of Cargoes and Containers (CCC10)."    

Addressing ammonia’s toxicity and safety concerns, Blackmore advises, "Besides hazardous area zoning, we’re implementing toxic area zoning. Mitigation of the hazards will be presented through design, best practices, the hierarchy of engineering controls, judgment and standardization. The inherently safer designs will be achieved by eliminating or reducing hazards with the greatest impact achieved during the initial design phase."

Blackmore notes the environmental impact of N2O (nitrous oxide) and ammonia emissions through slippage is another concern: "Other considerations will be how to inspect, maintain and survey safely. Survey procedures will require Risk Based Design (stage 5), corrosion, cracking, detection and alarm systems, increased ventilation rates, equipment allocation and transparent, approved change management."

Kevin Lim, Principal of the Singapore-based strategic advisory firm Blunomey, highlights the current status and challenges of using ammonia as a marine fuel. 

"The IMO has not given official approval to ammonia as a maritime fuel yet, but the momentum is there," says Lim. He explains that major engine manufacturers and shipping companies are developing and testing ammonia-powered engines and vessels with significant progress being made by engine manufacturers like Wärtsilä and MAN Energy Solutions.

"We already have vessels that can carry ammonia,” Lim states. “The vessels that've been carrying LPG obviously can be refurbished to carry ammonia. The main challenge is not new infrastructure requirements but scaling up the existing infrastructure. Safe-handling procedures and technologies are being developed to mitigate risks. However, there’s still some way to go for crew members to feel comfortable handling ammonia on board vessels."

Lim points out several technical challenges including the requirement for cold storage conditions: "You need a lot more storage space onboard, so that means only certain vessels are suited to adopting ammonia. Also, it must be stored below zero with a boiling point of -33.4°C. Ammonia is not very flammable but it’s highly toxic, necessitating stringent safety measures." 

Regarding infrastructure, Lim emphasizes the need to scale up existing facilities: "Many ports globally cannot handle ammonia. The distribution of bunkering facilities will need to be more evenly spread across shipping routes due to ammonia's lower energy density compared to traditional, carbon-based fuels."

Global Centre for Maritime Decarbonization

The Global Centre for Maritime Decarbonization (GCMD) is a collaborative initiative in Singapore focused on advancing maritime decarbonization through innovative projects, partnerships and scalable solutions, states Wee Meng Tan, Chief Projects Officer. 

"We’re focusing on closing the gap in ammonia bunkering safety and planning for phase two development in Singapore,” he adds. “We’re simulating ammonia bunkering by transferring cargo from chemical tanks to understand the intricacies involved." 

This focus on safety and simulation is crucial as the organization prepares for the first ship-to-ship (STS) transfer of ammonia in Singapore's port waters. "We’re closely following the development of interim guidelines by the IMO for the use of ammonia as fuel,” says Tan. “These guidelines will support the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code)."

Market supply and demand for ammonia are expected to evolve with technological advances and infrastructure development. Ensuring a reliable supply of green ammonia will be crucial for its widespread adoption.

GCMD has a clear vision for adopting ammonia as a marine fuel. "We anticipate fully designed vessels with ammonia engines could be operational by 2026 to 2027,” Tan predicts. “These vessels will be equipped with all the necessary safety and handling features to ensure safe operation." 

Nonetheless, the economic considerations of ammonia production still need to be improved. "The current economics of ammonia production are challenging,” says Tan. “However, with increased investment and technological advancements, we expect the cost of green ammonia to become more competitive with traditional marine fuels. Our long-term vision is to establish a sustainable and resilient supply chain for ammonia, enabling the maritime industry to transition to a zero-carbon future. By 2027, we aim to see significant progress in adopting ammonia as a marine fuel."

Strategic Insights

Punit Oza, Founder of Maritime NXT and Director of Quarks Asia, highlights ammonia's potential. He emphasizes its geopolitical benefits, noting it can be produced globally, unlike fossil fuels concentrated in specific regions, thus reducing geopolitical tensions related to energy supply. 

"Ammonia allows the maritime industry to go beyond pure geopolitical aspects and diversify the sources of this fuel," explains Oza. "Green ammonia, produced from electrolyzing water and separating hydrogen and oxygen, can be built across the globe wherever required. This decentralizes production, making it more resilient and less dependent on specific regions."

Regarding infrastructure and handling, Oza points out that the existing ammonia infrastructure, widely used in the fertilizer industry, can be adapted for maritime use: "The traditional ammonia infrastructure, including storage and handling, is not an unknown commodity like hydrogen or methanol." 

Reflecting on historic transitions, Oza remarks that shipping's past shift from coal to oil shows adaptability to new fuels. He suggests the transition to ammonia and other alternative fuels will be faster due to more resources and smarter testing methods: "Shipowners who have earned substantial profits in recent years should invest in ammonia-combustible engines to break the chicken-and-egg situation. By committing to ammonia, they can drive demand and encourage further investment in production and infrastructure." 

Staged Approach

Oza explains that ammonia's demand in shipping will grow gradually, allowing the fertilizer industry to adapt and supply both sectors. "This staged approach will help balance demand and supply without causing significant disruptions," he notes. "Collaborating with stakeholders and aligning commercial and technological efforts are essential for the successful adoption of ammonia."– MarEx  

Technology columnist Sean Holt writes from Singapore.