MAN ES Achieves its First Combustion of Ammonia in a Two-Stroke


Published Jul 6, 2023 6:25 PM by The Maritime Executive

The MAN research center in Copenhagen has been setting up to test ammonia-fueled engine configurations, and in a major breakthrough for the industry, it has achieved first combustion with ammonia.

Tests will continue in the coming weeks and months to document and explore the combustion process in the two-stroke engine, according to MAN. The engineers will adjust injection and other parameters to optimize the design, learning more about how ammonia will work as a marine fuel along the way. 

Interest in the breakthrough has been "overwhelming," according to Bjarne Foldager, the company's Head of Two-stroke Business.

“We provide the technology. The industry has the will to implement. Now it’s up to the International Maritime Organization to establish clear regulation that ensures the maritime industry is not penalized for choosing carbon-free fuels like ammonia and methanol,” said Foldager.

The firm announced the breakthrough on the second-to-last day of IMO MEPC 80, while delegates were still debating the level of emissions reductions to target for 2050. 

MAN ES' testing program was slightly delayed in 2022 for safety upgrades at the testing center. That work was completed, and the firm has said that it will still be on track to deliver an ammonia-fueled two-stroke to a Japanese shipbuilder next year. 

Ammonia has already been successfully tested in four-stroke engines. Wärtsilä began testing an ammonia-fueled four-stroke in 2020 with progressively larger percentages of NH3 in the fuel mixture. IHI and Japan Engine Corporation tested a 280mm bore four-stroke running on 80 percent ammonia in May, and reported ultra-low levels of undesirable NOx and ammonia slip in the exhaust stream. The same engine design will be installed in an experimental ammonia-powered tugboat for delivery next year. 

It has also been tested in limited combustion tests in a two-stroke engine. Japan Engine reported in April that they had begun co-firing operation of a large low-speed two-stroke engine running partly on ammonia.. The engine uses a proprietary "stratified injection system" and is being tested at Mitsubishi Heavy Industries’ Research and Innovation Center in Nagasaki.