Ammonia- a potential marine fuel


Ammonia Bunkering: Understanding the Basics
Ammonia (chemical formula: NH3) is a compound composed of one nitrogen atom bonded to three hydrogen atoms. It is a colorless gas with a strong, pungent odor. Ammonia is highly soluble in water and forms a strongly alkaline solution, often referred to as ammonium hydroxide. The marine industry is increasingly looking for alternative fuels to meet the rising environmental challenges, particularly in reducing greenhouse gas emissions. The shipping sector is considering ammonia as a possible alternative marine fuel. The procedure of supplying ships with ammonia as a fuel for their engines is known as ammonia bunkering. Due to its potential to be produced using renewable energy sources and its potential to release zero greenhouse gas emissions when produced using renewable energy sources, ammonia, a colourless gas made up of nitrogen and hydrogen, has been highlighted as a potential alternative maritime fuel.

Ammonia fuel is delivered to ships via specialized bunkering vessels or terminals during the ammonia bunkering process. The ammonia is kept in tanks that are specially constructed for keeping this kind of fuel safely stored, and the distribution process requires several safety measures.

The availability of ammonia for bunkering varies depending on the geographical location. Ammonia is mostly used in the fertilizer industry, and hence, its availability is more prominent in regions where agricultural activities are more prevalent. Currently, ammonia is manufactured in vast amounts as a raw material for goods used in the chemical and fertilizer sectors. It will take a significant increase in production capacity to realize the large-scale production of “green ammonia” for maritime shipping; the current installed global capacity of wind and solar farms, and especially the electrolysers needed to produce the necessary green hydrogen for ammonia production, are dwarfed by the required capacity.
It will be necessary to generate renewable electricity for the electrolysers in areas across the world with favourable wind and solar radiation (or other low carbon power generation) conditions. It should be mentioned that using typically costs less and is more effective.

Ammonia is not used as a fuel by oceangoing ships at the moment, but recent analysis of the necessary land storage and distribution, onboard storage, and conversion to energy – in either an internal combustion engine or in a fuel cell – has revealed no insurmountable barriers to its use. While it is hazardous and the environmental, health, and safety risks that are associated with them can be controlled. Therefore, it seems sense to draw the conclusion that ammonia can be a good marine fuel.

There are numerous current research and development efforts that aim to create guidelines for the use of ammonia as a fuel. The circumstances under which ammonia can be utilised as a fuel will become more evident once those criteria have been fully created.

With the use of renewable electricity, ammonia may be generated with nearly no greenhouse gas (GHG) emissions from well to wake. The majority of ammonia produced so far is “grey ammonia,” which has higher well-to-wake GHG emissions than traditional marine fuels.
Because ammonia contains no carbon, sulphur, or other contaminants typically found in conventional residual or distillate fuels, using it as a fuel for a marine internal combustion engine results in emissions of sulphur dioxide, carbon monoxide, heavy metals, hydrocarbons, and polycyclic aromatic hydrocarbons (PAH) dropping to zero and harmful particulate matter (PM) emissions being significantly lower than for conventional fossil fuels. Pilot fuel and cylinder combustion will produce the majority of the emissions of particulate particles.

The inland production, distribution, storage, and use of ammonia are all subject to laws, and the IGC Code (The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk) also addresses its shipment by ship. To increase the use of ammonia as a marine fuel, this framework would need to be modified; in the meantime, class societies can support shipowners by using well-established, risk- based “alternative design” approval methodologies. These methodologies have been used for alternative fuels.
There are ongoing regional initiatives being established, such as the EU’s ‘Fit-for-55′ package of policies, which are projected to give incentives and encouragement for shipping to use alternative low- and zero-carbon fuels, such as (green) ammonia, with the purpose of lowering GHG emissions from shipping.

Risk and Safety
The analysis has focused on two cargo ships (an oil tanker and a bulk carrier) and a Ro-Pax ship. The results of the investigation show that the main safety issue with ammonia is related to its toxicity and gas-dispersion characteristics. Although there are answers, more research and study are required to effectively mitigate or further reduce the hazards.
For the aforementioned ship types, precautions and suggestions have been made in order to minimize the risks and effects of potential dangers. While the IGF Code and the use of methane as a marine fuel have introduced certain protections, the intrinsic and unique dangers of utilising ammonia aboard ships have led to the addition of many more.

Ammonia Types for Bunkering
Ammonia is a viable alternative fuel for shipping, and two varieties are frequently used for ship bunkering:
1. Anhydrous Ammonia: This form of ammonia is extremely concentrated and is frequently kept in pressurised tanks. Without any water, it is made entirely of ammonia gas. Aqueous ammonia is less energy dense than anhydrous ammonia, which makes it a less effective fuel for shipping. It needs to be handled carefully because it is also quite poisonous.

2. Aqueous Ammonia: This is an ammonia solution that is typically 10–35% concentrated in water. Other names for it include ammonia water and ammonia solution. In addition to being safer to handle and carry than anhydrous ammonia, aqueous ammonia also has lower toxicity. But it has a lower energy density than anhydrous ammonia and requires more space for storage.

In terms of bunkering in ships, each form of ammonia has benefits and drawbacks. The decision between the two is influenced by a number of variables, such as the shipping route, the type of vessel, and the accessibility of infrastructure for ammonia fueling.

Storage of Ammonia
Depending on the type of ammonia and the needs of the ship, there are several ways that it can be stored in ships as a fuel. Ammonia can be stored either completely pressured at 18 bar or in a liquid state at atmospheric pressure. It doesn’t need to be stored at the same volume as hydrogen or at the cryogenic temperatures needed for LNG. Because of this, it is a better petrol to carry and a strong contender to be used as maritime fuel. Cryogenic tanks, which can keep anhydrous ammonia at a temperature of -33°C, are one possibility. Anhydrous ammonia is often held under high pressure, therefore the tanks need to be well-insulated to avoid leaks or rupture. Another choice is to keep aqueous ammonia in special tanks built of ammonia-compatible materials. Since aqueous ammonia is normally maintained at room temperature and pressure, it is simpler to handle than anhydrous ammonia.Ships that burn ammonia as fuel need storage tanks as well as specialized tools like fuel lines, pumps, and injectors to get the ammonia to the engine.Given its poisonous and combustible characteristics, safety procedures are also required to guarantee that the ammonia is handled and stored properly. Ammonia leaks and spills can be extremely dangerous to both people’s health and the environment.

In order to avoid accidents and ensure safe operation, ammonia handling, and storage must adhere to safety laws and best practices. Guidelines for the use of ammonia as a marine fuel have been established by the International Maritime Organisation (IMO), and they address environmental, operational, and safety issues. The design and building of ships, the handling and storage of ammonia, and the use and maintenance of ammonia fuel systems are all covered by these regulations.

SWOT analysis of ammonia as a marine fuel:

SWOT analysis is a useful tool for decision-making, risk assessment, and strategic planning as it helps organizations to identify key factors that affect their performance. Here is a SWOT analysis for ammonia bunkering:

• Environmental Benefits: Ammonia bunkering offers the potential for significant environmental advantages over traditional fossil fuel bunkering. Ammonia produces no carbon dioxide (CO2) emissions when burned, making it a promising solution for reducing greenhouse gas emissions in the maritime industry.
• Energy Density: Ammonia has a high energy density, allowing for efficient energy storage and utilization in marine engines. This characteristic makes it a viable option for providing the necessary power and performance required for long-haul shipping.
• Abundance and Production Capacity: Ammonia can be produced from various sources, including renewable energy, natural gas, and biomass. Its production capacity can be scaled up to meet future demand, potentially enabling a secure and reliable supply chain for ammonia bunkering.

• Safety Considerations: Ammonia is a toxic and flammable substance that requires strict safety protocols during handling, storage, and bunkering operations. The risks associated with ammonia leaks or accidents necessitate specialized infrastructure, equipment, and training to ensure safe operations.
• Infrastructure Development: Establishing a comprehensive ammonia bunkering infrastructure is a significant challenge. Building the necessary production facilities, storage terminals, and bunkering stations requires substantial investments and coordination among stakeholders. Developing the infrastructure on a global scale may take time and face regulatory and logistical hurdles.

• Regulatory Support and Incentives: Governments and regulatory bodies have the opportunity to provide support, incentives, and frameworks to facilitate the adoption of ammonia bunkering. Policies such as emission reduction targets, carbon pricing, and funding for research and development can incentivize industry players to invest in ammonia as a marine fuel.
• Technological Advancements: Ongoing research and development can lead to technological advancements that improve t ammonia bunkering systems’ efficiency, safety, and performance1 Innovations in ammonia-powered engines, emission control systems, and carbon capture technologies can enhance the viability and attractiveness of ammonia as a bunker fuel.

• Competition from Other Alternative Fuels: Ammonia bunkering faces competition from other emerging alternative fuels, such as hydrogen, liquefied natural gas (LNG), and biofuels. Each fuel option has its own strengths and weaknesses, and the market dynamics will determine which fuel gains prominence in the maritime industry.

• Market Acceptance and Demand: The success of ammonia bunkering relies on market acceptance and demand. Shipping companies and vessel operators need to see the economic and operational benefits of using ammonia as a bunker fuel. Generating sufficient demand to drive investments in infrastructure and production capacity may require overcoming initial skepticism and building confidence in ammonia as a viable option.

PESTLE analysis of ammonia as a marine fuel:

A PESTLE analysis is a tool used to assess the external factors that may impact a specific industry or business. Here is a PESTLE analysis for ammonia bunkering

• Regulations and Policies: Political factors play a crucial role in shaping the adoption of ammonia bunkering. Government regulations and policies related to emissions reduction, climate change, and maritime industry standards will impact the feasibility and attractiveness of ammonia as a bunker fuel.
• International Collaboration: Political cooperation and agreements among nations are essential for harmonizing regulations and establishing consistent standards for ammonia bunkering operations across different regions and jurisdictions.
• Cost Considerations: The economic viability of ammonia bunkering will depend on factors such as the cost of ammonia production, infrastructure development, and the price competitiveness compared to other bunker fuels. The availability of financial incentives, subsidies, or tax benefits can influence the cost dynamics and market adoption of ammonia bunkering.
• Fuel Price Volatility: Fluctuations in the price of traditional bunker fuels and other alternative fuels can affect the economic competitiveness of ammonia bunkering. Stability and predictability in fuel pricing are essential for long-term investments in ammonia bunkering infrastructure.
• Public Perception and Acceptance: The social acceptance of ammonia bunkering is crucial for its successful implementation. Public awareness, education, and understanding of the benefits and safety measures associated with ammonia as a bunker fuel are important factors that can influence public opinion and support for this technology.
• Stakeholder Engagement: Engaging with various stakeholders, including local communities, environmental groups, and industry associations, is vital to address social concerns, build trust, and ensure transparency throughout the development and implementation of ammonia bunkering projects.
• Technological Advancements: Ongoing research and development in ammonia-powered engines, emission control systems, storage and bunkering technologies, and safety protocols are essential to enhance the efficiency, safety, and reliability of ammonia bunkering. Advancements in related technologies can drive the wider adoption of ammonia bunkering in the maritime industry.
• Infrastructure and Logistics: The development of specialized infrastructure and logistics systems for ammonia bunkering is a significant technological challenge. Innovations in storage facilities, transfer mechanisms, and safety systems are required to support the efficient and safe supply chain of ammonia as a bunker fuel.
• Compliance and Safety Regulations: Legal frameworks related to safety, transport, storage, and handling of ammonia need to be established or updated to ensure compliance with national and international standards. Regulations regarding emissions, environmental protection, and worker safety will shape the legal landscape for ammonia bunkering operations.
• Liability and Insurance: Clear guidelines and regulations are needed to address liability and insurance considerations associated with ammonia bunkering. Determining responsibility in case of accidents, spills, or damages related to ammonia bunkering operations is an important legal aspect that requires attention.

• Climate Change Mitigation: The environmental benefits of ammonia bunkering in reducing greenhouse gas emissions align with global efforts to combat climate change. The potential for ammonia to contribute to decarbonizing the maritime industry makes it an attractive option from an environmental perspective.
• Environmental Impact: While ammonia itself has minimal carbon emissions, the environmental impact of ammonia production and potential leakage or accidental releases during bunkering operations must be carefully assessed and managed. Robust environmental regulations and monitoring systems should be in place to minimize any adverse effects.
Future Challenges
While ammonia has the potential to become a key marine fuel in the future, there are several challenges that need to be addressed to ensure its safe and effective use in the shipping industry.

Some of the key challenges include:

1. Safety and Risk Management: Ammonia bunkering presents inherent safety risks due to its toxicity and flammability. Ensuring proper safety protocols, training, and emergency response measures will be crucial to minimize the risks associated with handling, storage, and bunkering operations. Developing and implementing robust safety standards, guidelines, and regulatory frameworks specific to ammonia bunkering will be necessary.
2. Infrastructure Development: Establishing a comprehensive and reliable ammonia bunkering infrastructure on a global scale is a significant challenge. It requires investments in production facilities, storage terminals, bunkering stations, and related logistics. Coordinating infrastructure development among different stakeholders, including ports, shipowners, and fuel suppliers, will be necessary to support the growth and adoption of ammonia bunkering.
3. Technological Advancements: Continued research and development are needed to optimize ammonia-powered engines, propulsion systems, and emission control technologies. Enhancing the efficiency, reliability, and performance of ammonia-based marine engines will be crucial to ensure their competitiveness and wider adoption. Moreover, innovations in storage, transfer, and handling technologies are essential to enhance the safety and operational aspects of ammonia bunkering.
4. Scaling up Ammonia Production: Meeting the demand for ammonia bunkering requires significant scaling up of ammonia production, particularly from renewable and low-carbon sources. The availability, cost, and sustainability of ammonia as a fuel depend on the development of efficient and cost-effective production methods. Overcoming challenges related to scaling up production capacity, including access to feedstock and securing renewable energy sources, will be critical.

5. Regulatory Frameworks and Standards: Developing comprehensive and harmonized regulatory frameworks is necessary to ensure consistent and safe ammonia bunkering operations globally. Regulations should address safety, environmental, and operational aspects of ammonia bunkering, while also aligning with existing maritime regulations. Collaboration between governments, industry stakeholders, and regulatory bodies is crucial to establish these frameworks and standards.
6. Market Acceptance and Demand: Generating market acceptance and demand for ammonia bunkering will be a significant challenge. Demonstrating the economic viability and environmental benefits of ammonia as a bunker fuel, along with clear advantages over other alternative fuels, will be essential. Building confidence among shipping companies, vessel operators, and investors in the long-term viability of ammonia bunkering is critical to drive market adoption.
7. Knowledge and Awareness: Increasing knowledge and awareness about ammonia bunkering among industry stakeholders, regulators, and the general public is important. Education, training programs, and information campaigns can help address misconceptions, promote understanding of ammonia bunkering technology, and garner support for its development and implementation.


Ammonia offers a number of benefits that make it a promising fuel to help decarbonize ships. Given that it is naturally carbon-free, if it is produced with renewable energy sources, it can significantly reduce the GHG emissions from well to wake. Since there is information on how to handle, store, and use ammonia, it is produced and used in enormous quantities in various sectors. It is well known and established that ammonia may be produced using the Haber-Bosch process and electrolysis. Ammonia is a well-known cargo in the shipping sector, where it has been shipped on LPG ships in accordance with already in place laws like the IGC code(The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk). It is reasonable to infer that ammonia will likely be adopted as a marine fuel based on the increased interest in ammonia-fueled vessels and the initiatives that have been announced to create green ammonia.

There are still obstacles, nevertheless, that the industry, engine manufacturers, producers, and other industry groups, as well as policymakers and regulators, need to overcome jointly. Despite having a lot of handling experience, only few people are familiar with using ammonia as a fuel. There are some questions about how safe it is to use ammonia as fuel for ships and their engines given that it is poisonous and corrosive. Therefore, more research is required to fully comprehend these hazards and any potential means of reducing them. When ammonia absorption occurs, there is a need for more rules and regulations due to the increase in operations (such as bunkering) and human contact.

Ammonia has an excellent and promising future, but for it to promote the decarbonization of shipping as an alternative fuel, immediate action is required to remove all roadblocks.

– Sakshi Bhat