Ammonia as marine fuel: the next big frontier

As the maritime industry embarks upon the fourth propulsion revolution, ammonia has been identified as one of the key alternatives to fossil fuels in the shipping’s pathway toward becoming carbon neutral.

There has been a notable increase in the uptake of large ammonia vessels over the past year, according to Getting to Zero Coalition’s latest edition of zero-emission project mapping.

Over this period, ten large ammonia demonstration projects have been launched, bringing the total to 14. The market is also witnessing some of the first orders for these ammonia vessels being placed.

Earlier this year, Greek shipowner Avin International LTD contracted the Chinese shipbuilder New Times Shipbuilding Co. to build the first ammonia-fuel-ready vessel in the world. The company has options for two further vessels.

Major strides are being made on the design front as well with several shipbuilders winning approvals for their concept designs.

The most recent one has seen the Korean Register (KR) grant approval in principle (AIP) for an 8K ammonia bunkering vessel to KMS EMEC, a design engineering company. The ship has been developed by KR, KMS EMEC, and Singapore’s shipping company Navig8.

In addition, Japanese majors NYK Line, Japan Marine United Corporation (JMU), and ClassNK have signed a joint R&D agreement for the commercialization of an ammonia-fuelled ammonia gas carrier (AFAGC) that would use ammonia as its main fuel.

Apart from AFAGC, the companies will be engaged in the R&D of a barge that is equipped with a floating storage and regasification facility exclusively for ammonia for the first time in the world.

Ammonia has an acceptable energy density, similar to methanol, and even higher than that of hydrogen. It can be stored at a temperature of -33°C, requiring less cooling than for example LNG.

This also enables its storage on board vessels to be economically viable.

As a zero-carbon fuel, ammonia can be produced by combining water, air, and renewable energy, which is commonly referred to as green ammonia.

It can also be generated from gas feedstock with carbon capture and storage technology, generating what is known as blue ammonia.

Currently, it is rather expensive, especially when it comes to green ammonia, however, prices are expected to go down as the demand for ammonia spurrs the scaling up of its production.

However, there are major safety issues that need to be tackled when discussing ammonia as potential marine fuel of the future, the most important one being its high toxicity.

The use of ammonia can be seen as a major safety hazard for people because of the health dangers caused by exposure through inhalation or skin contact.

Hence the most important aspect to developing an ammonia-powered engine or an ammonia-fuelled ship will be making sure potential ammonia releases are prevented and safe and quick handling of potential leakages is ensured.

Some of the most important considerations to have in mind when designing these types of ships are venting and draining systems, as well as material selection, because ammonia is highly corrosive, as explained by Haeki Jang, Vice President, Hull Outfitting Engineering Team, Samsung Heavy Industries.

Even though ammonia is being promoted as a zero-emission fuel option, which doesn’t emit CO2, combustion of ammonia may produce other emissions, such as Nitrous oxide (N₂O).

Nitrous oxide is a potent greenhouse gas, which is much more toxic than traditional fuels. Consequently, the potential release of such gases into the atmosphere or the sea must be prevented.

“Ammonia is relatively easy to handle, it is well-known in the industry, and it has properties that are suitable for an internal combustion engine,” Brian Østergaard Sørensen, Vice President, Head of Research & Development Two-Stroke, MAN Energy Solutions, said in a webinar recently.

As explained, by controlling the combustion process, the company wants to avoid producing any type of GHGs including N2O. The engine manufacturer aims to have a commercially available ammonia-burning engine ready in 2024.

As an alternative to the combustion engine, the maritime industry is also looking at the development of solid oxide fuel cell (SOFC) technology.

When based on fuels such as ammonia, hydrogen or bio-methane, SOFCs hold great promise as a replacement for today’s fossil fuels.

By electrochemically converting fuel into electricity, SOFCs can potentially produce power with higher efficiency than internal combustion engines.

One of the first projects in this field is expected to see an ammonia fuel cell system installed on board Viking Energy offshore vessel in late 2023.

The roll-out of ammonia is likely to be faced with a similar scenario as it was the case with LNG, when ships were ready much earlier than the land-side operations and infrastructure.

Trying to get ahead of the curve, industry major Maersk has teamed up with several companies from the sector on setting up the necessary bunkering infrastructure to make ammonia a reality.

The companies taking part in the project include A.P. Moller – Maersk A/S, Fleet Management Limited, Keppel Offshore & Marine, Maersk Mc-Kinney Moller Center for Zero Carbon Shipping, Sumitomo Corporation and Yara International ASA.

The project participants plan to carry out a feasibility study aimed at establishing a comprehensive supply chain for the provision of green ammonia ship-to-ship bunkering at the Port of Singapore.

The study will cover the entire end-to-end supply chain of ammonia bunkering, the design of ammonia bunkering vessels, as well as related supply chain infrastructure.

When it comes to bunkering ammonia, there are three options:

• a tank lorry- not a proper solution due to the needed quantity of ammonia/speed of loading for a large seagoing ship
• ammonia terminal- accessibility for large cargo ships very limited
• bunkering vessel – most feasible option

The bunkering process is not expected to differ too much from the process of ammonia cargo loading, especially since ship-to-ship loading is possible. Consequently, the technical details such as ship-to-ship connections for cargo and bunkering operations should not differ much.

When it comes to safety and infrastructural challenges involving ammonia, the cooperation of different industry partners through research and development projects is put forward as the solution.

MAN Energy Solutions is currently involved in several R&D and demonstration projects focusing on ammonia as a marine fuel.

One of those projects is led by Malaysia’s shipping group MISC Berhad, South Korean shipbuilder Samsung Heavy Industries (SHI), UK’s classification society Lloyd’s Register (LR), and most recently Maritime and Port Authority of Singapore and Norwegian fertilizer company Yara International.

Also known as the Castor Initiative, the project aims at developing ammonia propulsion ships to support the maritime industry’s drive to decarbonization.

MISC Berhad hopes to be able to order its first ammonia-burning ship by 2025 as a result of the initiative.

Mark Darley, Marine and Offshore Director, Lloyd’s Register, agrees that collaboration and demonstration projects are at the core of developing solutions to meet the IMO 2050 targets.

“As an industry, we have to move from words to action, and then from action to pilots and prototypes, and ultimately, commercially-viable, deep-sea vessels,” he said during the webinar.

“Industry-wide and LR’s own research shows that zero-carbon vessels will be a reality and will be entering the fleet by 2030s.”

Demonstration projects have been described as the best tool to create pathways toward concrete results, bringing more transparency into the industry, and enabling companies from different sectors to share knowledge thus minimizing possible uncertainties.

Ultimately, outcomes and concrete results of demonstration projects are targeted at giving more confidence to the market for the commercialization of these solutions.

These types of projects are vital in helping the industry understand the safety risks, but also operational challenges when dealing with new fuels and solutions to move the transition forward.

They are also a great way for the industry to save money and identify technical and operational hurdles early on.

According to LR, learnings from demonstration projects are key in developing prescriptive regulations for various aspects of the introduction of new fuels. These can cover fuel quality, safety issues, ship design and operation, bunkering, training of crews, and accommodation of fuels, as there are a lot of areas where such rules are currently missing.

Introduction of ammonia as a marine fuel in the industry is expected to bring in additional safety regulations when designing ammonia-powered and ammonia-bunkering ships.

One of the potential solutions is likely to be the development of gas detection systems and their adaptation to ammonia onboard ships. Furthermore, engine safety requirements are also expected to be introduced to make sure potential leakages, if any, are detected in time and dealt with properly.

What is more, specific training of crews to handle ammonia-powered ships would have to be devised, regulated and introduced into the sector, the primary focus being safety.

In conclusion, the industry must take a proactive approach to find solutions to its decarbonization challenge as pressures to become greener grow from across the board.

Only in this way can it remove the veil of uncertainties lying ahead. By taking a step-by-step approach through joint R&D and pilot projects clear guidelines and pathways can be created.

This will pave the way for setting up the regulatory framework, making it easier for the shipping industry to adopt and adapt to the new fuels in a safe and transparent way.