As the global maritime industry strives to reduce its carbon footprint, C-Job is looking at cleaner and greener alternatives to conventional fossil-based fuels. For years, C-Job has been a strong believer in ammonia as a marine fuel and first explored its potential in 2016 and published extensive research into the subject in 2019. The research showed that ammonia can safely and effectively be applied as a marine fuel.


What is ammonia?

Ammonia – NH3 – is a colorless gas. It is a compound of nitrogen (N) and hydrogen (H), both of which are abundant elements.

  • Nitrogen can be obtained from an air separation process.
  • Hydrogen can be obtained from the electrolysis of demineralized water.

The process to obtain and combine nitrogen and hydrogen into ammonia requires electricity. In this way, ammonia production is an ideal way to utilize the (over)capacity of solar and wind-generated electricity.

Ammonia is produced by combining nitrogen and hydrogen in the Haber–Bosch process.


Ammonia as a marine fuel

There are many benefits to using ammonia as a renewable fuel in the maritime industry. It has no sulfur oxide (SOx) and no particulate matter emissions. If the whole supply chain is sourced from renewables, it is a carbon-free fuel.

Due to its long history in the fertilizer industry, ammonia is an easily sourced material with established working practices.

Ammonia production is straightforward and the internal combustion engine to use ammonia as a marine fuel already exists and fuel cell technology is advancing fast. Combined, ammonia is a renewable fuel with much potential.

“Reviewing all ammonia power generation options, the Solid Oxide Fuel Cell (SOFC) is clearly the most efficient. However, it does have practical challenges as the power density and load response capability are not on an acceptable level yet. Therefore, in the short term applying the internal combustion engine is the way to go.”
- Niels de Vries, Lead Naval Architect
C-Job Lead Naval Architect Niels de Vries black and white
Ammonia carrier concept render at sea side view cropped

Ammonia 2-4

C-Job Naval Architects, along with a consortium of leading maritime companies and partners, have received a 10 million euro subsidy from the European Union to fund the Ammonia 2-4 project. C-Job, Wärtsilä, DNV, Mediterranean Shipping Company (MSC), and the Italian National Research Council (CNR) have joined forces for the project. The subsidy has been granted to be used in conducting research to help accelerate the implementation of ammonia as a marine fuel. Ammonia 2-4 will develop full-scale demonstrators for both four-stroke and two-stroke engines to run on ammonia by 2025.

The aim of the Ammonia 2-4 project is two-fold. Both a two-stroke engine and a four-stroke engine running on ammonia as a main fuel will be demonstrated in lab conditions closely mimicking real-life conditions. Following successful demonstration, the two-stroke engine will be retrofitted onto an existing vessel owned and operated by MSC.


C-Job research: ammonia carrier fueled by its own cargo

The research performed by Niels de Vries uses an ammonia carrier concept design which is fueled by its own cargo to compare the performance of ammonia as a fuel versus conventional fuel. The ammonia carrier features an internal combustion engine that uses an ammonia hydrogen mixture (ICE SI). Additionally, in the design of the bulk carrier, transporting ammonia as cargo, all safety aspects required were incorporated.

The result shows that ammonia can be used as a marine fuel when a number of safety measures are incorporated into the design. A full risk assessment with design consequences for a fuel system using ICE with an ammonia hydrogen mixture is included in the C-Job research by Niels de Vries.

The research was awarded the Maritime Designer Award at the Maritime Awards Gala in 2019.



The Ammonia Energy Association is an international industry association with the aim to promote the adoption and use of ammonia in a sustainable energy economy. C-Job Naval Architects has been a member of the association since 2018 in a further commitment to research ammonia’s potential. Together we collaborate with other industries and have the ambition to realize a safe and efficient ammonia-fueled vessel.

ENGIMMONIA is a consortium of companies and organizations from the maritime sector that together are looking at ways of contributing to the decarbonization of our industry. The EU-funded project started in 2021 and will run for four years. Its main objectives are to accelerate the introduction of alternative fuels, with a particular focus on ammonia. and the identification and transfer to the maritime sector of proven clean energy technologies already in use in terrestrial applications.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 955413.