MAN ES ignites excitement: Single-cylinder test of long-awaited ammonia engine about to kick off

As the shipping industry faces mounting pressure to accelerate decarbonization efforts, engine manufacturers are racing to develop innovative technologies that will facilitate a greener future for maritime transportation.

Among the promising contenders is ammonia, a potential alternative fuel that has gained significant attention in recent years. The industry is already making studies around green corridors and the availability of ammonia as a green fuel, relying heavily that one engine maker will deliver on its promise to provide the missing part of the puzzle in time: the engine.

MAN Energy Solutions aims to have a commercially available two-stroke ammonia engine by as early as 2024, followed by a retrofit package for the gradual rebuild of existing maritime vessels by 2025.

Speaking about the ongoing research and development project aimed at developing a marine engine that burns ammonia, Hrishikesh Chatterjee, Promotion Manager for 2 Stroke Engines at MAN Energy Solutions based in Copenhagen, said that the project is ‘looking good’.

Mr. Chatterjee spoke on MAN ES dual-fuel engines during a webinar hosted by Riviera Maritime on Tuesday, May 30.

The german engine manufacturing powerhouse is set to test its ammonia-powered marine engine at its test bed facility in Copenhagen by the end of this month and moving into the beginning of June.

The test bed facility has been the berthing place for all of the company’s dual-fuel technologies, including LNG, LPG, and methanol.

“However, timelines are getting squeezed. We have promised the market that we will have the first ammonia-powered engine delivered to the shipyard at the end of 2024, which is around the corner,” Hrishikesh said.

“The engine is ready to burn ammonia on a single cylinder. And based on the outcomes of the test, the full engine will be developed and released to the shipyard. The market introduction plan is based on positive seagoing experience.”

As explained by Hrishikesh, it will be critical to collect data for approximately one year of service to fully understand the engine’s mechanical behavior, performance, and emissions across various operating conditions.

Therefore, the commercial release of the ammonia-powered engine to the maritime industry will occur only after an extensive seagoing experience, as it is crucial to ensure the technology’s reliability and compliance with strict environmental regulations. Once all of these conditions are proven to be reliable, the engine can move to the next stage, enabling owners to place orders.

“We need this technology to work and work at the first ‘go’, because there is a huge pressure and expectation from the market,” Hrishikesh pointed out.

MAN Energy Solutions has placed safety at the forefront of its engine testing procedures, Hrishikesh noted. Recognizing that ammonia is a highly toxic and hazardous substance, the company has implemented comprehensive safety measures and risk assessments to mitigate potential dangers.

With the necessary safety protocols in place, the focus of the ammonia combustion tests will shift toward emissions control and engine performance.

“We have kept safety at the center and all of our risk assessments are based on that. But, we have crossed that stage and we are actually going to burn the ammonia. The key focus will be emissions and performance because we have extensive knowledge about the other aspects of the engine. We are doing it on a single cylinder as this has been the guiding principle for all other dual-fuel engine designs. Basically, you burn the test fuel on a single cylinder and keep the other units on fuel oil to have stable running conditions,” Hrishikesh noted.

This approach enables the engine manufacturer to tweak the performance of the engine in line with the test results. Based on the findings from this test, all the units will be converted into ammonia, when MAN Energy Solution expects to get a complete picture of the engine’s environmental footprinte and mechanical conditions.

MAN ES started working on a B&W two-stroke engine operating on ammonia back in 2019 with a pre-study of the fuel supply and injection concept combined with several hazard and hazard and operability studies (hazid/hazop) together with classification societies, shipowners, yards, and system suppliers.

The general design of the engine is expected to inherit the main features from the well-known LGP supply system for liquid injection.

When it comes to the parameters for fuel supply and injection pressures for ammonia, they are currently set at 80 bar and 600-700 bar, respectively. However, these parameters are subjects of further research and optimization in the engine testing process.

Ammonia liquefies at a relatively higher temperature of -33°C, and it can be stored at pressures above 8.6 bar at room temperature (20°C). To ensure its liquid phase is maintained in the event of an increase in ambient temperature, non-refrigerated ammonia tanks are typically designed to withstand pressures of approximately 18 bar.

Being a corrosive substance, MAN ES has been working to establish a comprehensive system that encompasses the entire ammonia fuel cycle, starting from the fuel tank and extending to the engine. This involves conducting experiments with double-walled structures, exploring various material solutions, developing intelligent software, and seeking optimal process techniques. It is crucial to design the process correctly to prevent the release of nitrous oxide (N2O), also known as “laughing gas,” into the atmosphere.

According to DNV, there are approximately 200 gas tankers equipped for transporting ammonia as cargo, with around 40 of them usually engaged in transporting ammonia at any given time. These vessels are the prime candidates for ammonia-fueled engines, as they already possess the necessary fuel on board and have hands-on experience in handling ammonia.

Additionally, it is worth considering the potential utilization of ammonia as fuel in other cargo-carrying ships before introducing it to passenger ships and cruise vessels.

That being said, we are already seeing shipping majors such as CMA CGM and ONE ordering ammonia-ready vessels. What is more, CMA CGM has taken delivery of its first ammonia-ready containership, the CMA CGM Masai Mara.

Overall, data from Clarksons from the end of 2022 showed that there were 130 “ammonia ready” and 6 “hydrogen ready” vessels on order. Almost six months into 2023, this number is even bigger.