MAN ES presses on with project to develop four-stroke ammonia-powered engine

Following the design and testing of its first two-stroke ammonia engine, Germany-based engine manufacturer MAN Energy Solutions (MAN ES) has launched the ‘AmmoniaMot 2’ research project that aims to develop a four-stroke, medium-speed, dual-fuel test engine powered by ammonia.

Backed by the German Federal Ministry for Economic Affairs and Climate Action (BMWK), the project reportedly began in August this year, and is scheduled to run for another three and a half years.

AmmoniaMot—which translates to “ammonia engine” in German—is the successor to an initial, eponymously named project that was launched in 2021 and wrapped up in May 2024. This project dealt with the ‘fundamental’ investigation pertaining to ammonia combustion in internal-combustion engines.

Its results are said to form the basis for AmmoniaMot 2, led by MAN ES with the same partners from the original project and supplemented by some new names, namely: WTZ Roßlau, Woodward L’Orange, the University of Munich (SFM), Neptun Ship Design, the University of Rostock (LKV), GenSys, and MNR.

“This project is the next logical step after the previous AmmoniaMot project. For us, the path to decarbonizing the maritime industry starts with decarbonizing fuels and, in this context, ammonia is an excellent candidate as it is carbon-free and thus avoids CO2-emissions when used as a fuel in our engines,” Alexander Knafl, Head of Engineering R6D Four-Stroke, MAN ES, highlighted.

As informed, within the scope of this project, MAN ES will be in charge of the entire engine concept for the ship application, including the exhaust-gas after-treatment system.

The WTZ Roßlau research institute will be responsible for developing the engine’s combustion concept and then testing the injection components ‘under realistic conditions’.

Engineering company Woodward L’Orange is set to create the injector prototype for the engine, while the University of Munich will oversee the 3D-CFD combustion simulation.

GenSys will be responsible for the construction of the demonstrator of the high-pressure fuel-supply module for ammonia (CAPSAM), which, in turn, will be engineered by Neptun Ship Design, all the while taking into account the safety requirements aboard ships, MAN ES explained.

The University of Rostock has reportedly been tasked with conducting experiments for the injection technology, exhaust-gas after-treatment, and ammonia engine lubrication as well as creating 0D/1D simulation models based on these experiments.

Finally, as understood, maritime company MNR will make the double-walled fuel system and the compensator for the high-pressure fuel piping system for ammonia.

Regarding the future application of ammonia-powered engines, MAN ES spotlighted that four-stroke engines could play a major role in newbuild passenger-less projects, such as cargo or special vessels, or as an auxiliary GenSet for large ammonia-powered two-stroke vessels.

When it comes to passenger ships, like ferries and cruise liners, on the other hand, the company revealed that its primary focus right now is on methanol and that the development of corresponding engines in parallel is well underway.

To remind, in June 2024, MAN PrimeServ, MAN ES’ after-sales brand, unveiled that it will provide a retrofit package for the conversion of conventional MAN four-stroke engines to dual-fuel methanol operation starting from 2025.

According to the company, the conversion package was ‘rigorously tested’ at its Augsburg, Germany plant since the summer of 2024.