Japan's NYK, partners sign contracts for world's first ammonia-fueled medium gas carrier

Japan's Nippon Yusen Kabushiki Kaisha, or NYK, has signed a series of contracts with Japan Engine Corporation, IHI Power Systems Co., and Nihon Shipyard Co., Ltd. to construct the world's first ammonia-fueled medium gas carrier, to be equipped with Japan-made engines, the companies, along with partner organization ClassNK, said in a joint statement.

This comes after the four companies were selected by Japan's New Energy and Industrial Technology Development Organization, or NEDO, for its Green Innovation Fund Project -- a Yen 2 trillion fund created in NEDO to accelerate structural transition of the energy and the industrial sectors to achieve carbon neutrality by 2050.

Since ammonia does not emit CO2 during combustion, it is expected to be a next-generation fuel that contributes to preventing global warming, the companies said Jan. 25.

The project is in line with Japan's decarbonization goals for its maritime industry and forms part of the slogan "Changing the future of the sea and the future with Japanese technology," they said.

As part of the collaboration, the four companies have been working with classification society ClassNK as a consortium on a "demonstration project for the commercialization of vessels equipped with a domestically produced ammonia-fueled engine," the companies said.

The scheduled delivery date for the 40,000 cu m ammonia fuel carrier is November 2026 and the ship is being built by shipbuilders Japan Marine United Corporation and Ariake Shipyard, the companies said.

The main engine -- one that turns the propeller to propel the ship -- comprises an ammonia fuel dual-fuel two-stroke engine produced by Japan Engine Corporation while the auxiliary engine -- one that drives the generator that provides the ship's electricity -- is an ammonia fuel dual-fuel four stroke engine produced by IHI Power Systems, they said.

Achieving goals, unlocking learnings

"Through the development and construction of the AFMGC, the consortium will contribute to the practical application of ammonia-fueled ships," the consortium said.

By establishing an ammonia value chain, the consortium will work to complete and popularize the AFMGC and other ammonia-fueled ammonia carriers, they said.

In addition, international rules for ships using ammonia as fuel are not yet in place, and the International Maritime Organization is currently discussing the issue, they said.

"This Project is one of the first to develop ammonia-fueled ships, and the knowledge gained from the construction and operation of AFMGCs will be essential to the progress of discussions at the IMO," they said, adding that the consortium aims to work closely with ClassNK and Japan's Ministry of Land, Infrastructure, Transport and Tourism, or MLIT, to contribute actively to international rulemaking.

Toward the completion of the ship in November 2026, the consortium will manufacture the main and auxiliary engines, begin detailed studies for the vessel's construction, and prepare an operation manual for actual operation, they said.

"After the ship is completed, the consortium will continue to operate the vessel for demonstration purposes to confirm the vessel's performance, including environmental friendliness and the practicality of the operation manual, and to provide user feedback to shipbuilders and marine equipment manufacturers for further improvements," they said.

Overcoming challenges

Ammonia is a viable solution to meet global shipping's decarbonization goals. However, its use as a bunker fuel also heralds some challenges, they said.

Because ammonia is a flame retardant, developing advanced technologies for stable combustion in engines is necessary, the companies said.

Nitrous oxide, which has a greenhouse effect of approximately 265 times that of CO2, may be generated during ammonia combustion. So, appropriate technology is required to tackle nitrous oxide emissions, they said.

In addition, ammonia toxicity is also a concern. Because ammonia is toxic, the vessel must be designed to prevent leakage from the piping and tanks. Even in the event of leakage, measures must be taken to protect the safety of the ship's crew, they said.

The companies said they were overcoming the various hurdles in its use.

The four companies designed a prototype vessel that overcame these challenges, and the prototype vessel obtained an Approval in Principle in September 2022 after a safety verification process that included confirmation of the safety concept and risk assessment by ClassNK.

To overcome toxicity, the consortium has already conducted a risk assessment review by ClassNK and a risk assessment and safety measures proposal from the user's point of view led by NYK's engineers, they said.

In May 2023, IHI Power Systems achieved the world's first stable combustion of fuel ammonia at an 80% co-firing rate with fuel oil in a four-stroke engine that is planned to be used as an auxiliary engine for an AFMGC, it said.

This experiment confirmed that emissions of nitrous oxide and unburned ammonia from the engine were virtually zero and that there was no ammonia leakage during operation and after shutdown, they said.