World first: Large marine two-stroke runs successfully on 100% hydrogen

Hydrogen combustion test on one cylinder of a MAN B&W 4S50ME-T was carried out at Mitsui E&S’s Tamano, Japan, facility. [Photo: Mitsui E&S] Hydrogen combustion test on one cylinder of a MAN B&W 4S50ME-T was carried out at Mitsui E&S’s Tamano, Japan, facility. [Photo: Mitsui E&S]

In what’s being claimed as a world first for the maritime industry, Japan’s Mitsui E&S Co. Ltd, a MAN Energy Solutions’ licensee, has successfully tested a 50-centimeter bore MAN B&W two-stroke engine at up to 100% load while running on hydrogen.

In collaboration with MAN Energy Solutions, Mitsui converted one of the four cylinders of an MAN B&W ME-GI (-Gas Injection) engine to hydrogen operation. The hydrogen was supplied from a hydrogen fuel supply system that Mitsui developed in 2023.

The ME-GI engine has played a major role in the uptake of LNG as a marine fuel and the fact that the Mitsui 100% hydrogen test was carried out on an ME-GI raises all sorts of interesting questions about the possibilities of converting exisiting LNG-fueled vessels to hydrogen-fueling.

Stable operation was achieved at various loads and operating conditions, including successful hydrogen combustion up to 100% load. Mitsui also confirmed greenhouse-gas emission reductions of up to 95%, with the remaining fraction originating from the pilot-fuel employed during testing.

“In this 100% engine load operation using hydrogen fuel, which ignites easily and requires proper combustion control, the company succeeded in covering the equivalent of 95% of the heat value with hydrogen fuel, and the cylinder pressure curve was equivalent to that of the other three cylinders operated with conventional fuel,” says Mitsui. “The company also confirmed that the hydrogen gas supply facility is capable of the stable supply of high-pressure hydrogen required from the engine. This is the world’s first success in hydrogen combustion operation of a large marine two-stroke engine with a bore size of 50 centimeters, and the company is steadily preparing to provide marine propulsion systems that can greatly contribute to the GHG reduction of the maritime industry with the success of the combustion test.”

“This is a very interesting project and one of several activities related to hydrogen that MAN Energy Solutions is currently pursuing within both two- and four-stroke segments,” said Gunnar Stiesch, chief technical officer, MAN Energy Solutions. “My congratulations to MITSUI for achieving this world-first and pushing the envelope on decarbonization.”

“We have worked closely with Mitsui on this research project and are very happy with the results achieved,” said Bjarne Foldager, country manager, Denmark, at MAN Energy Solutions. This proves the advantages and the flexibility of two-stroke engine technology, and means that we are now also prepared for the future, not only for hydrogen derivatives but also for hydrogen as a fuel. MAN Energy Solutions closely follows the market to keep track of any significant developments and this test is a noteworthy progression.”

“MAN B&W-branded engines are flexible by nature and designed for an easy retrofit at a later stage to different fuel types,” said Thomas S. Hansen, head of sales and promotion at MAN Energy Solutions. “This is an encouraging milestone for hydrogen as a fuel. We will now take some time to evaluate the results and ensure that we are ready to take action if and when the market for hydrogen matures.”