Another global first! Japanese shipbuilder bets on new energy vessels

In the technological development of the next generation of zero-carbon fuels, Japanese shipbuilders are once again at the forefront.

On March 7, Mitsui E&S announced that, together with its licensor MAN Energy Solutions, it successfully achieved hydrogen combustion operation of a large 50-centimeter bore marine two-stroke test engine at its Tamano Works. This is a world first and sets a new milestone for the maritime industry.

This hydrogen combustion operation used funds from the project jointly selected by Mitsui E&S and Daihatsu Diesel Manufacturing Co., Ltd. in fiscal year 2021 for the Ministry of Land, Infrastructure, Transport and Tourism's "Subsidy for Technological Development to Promote Maritime Industry Integration Cooperation." In this experiment, Mitsui E&S and MAN collaborated to modify one of the four cylinders of the test engine 4S50ME-T for hydrogen operation, based on the design of the LNG combustion ME-GI engine.

Meanwhile, the hydrogen used in the experiment was supplied from the high-pressure hydrogen supplied by Mitsui E&S's hydrogen supply system (liquid hydrogen tank, hydrogen compressor, etc.), which was completed last October. The test engine successfully underwent coupled operation at 100% load without any problems such as hydrogen leakage.

Mitsui E&S pointed out that in this 100% engine load operation using hydrogen fuel, the company successfully covered 95% of the calorific value using hydrogen fuel, and the cylinder pressure curve was comparable to the pressure curve of the other three cylinders operating with conventional fuel. The company also confirmed that the hydrogen supply system can stably supply the high-pressure hydrogen required by the engine.

Mitsui E&S stated that this is the world's first successful hydrogen combustion operation on a large 50-centimeter bore marine two-stroke engine. With the success of the combustion test, the company is steadily preparing to provide marine propulsion systems to make a significant contribution to greenhouse gas reduction in the shipping industry.

Mitsui E&S plans to contribute to the realization of a low-carbon society by developing hydrogen fuel propulsion system technology and hydrogen supply infrastructure-related technologies, and mastering the technologies and know-how related to the storage, supply, and utilization of hydrogen, the next-generation fuel.

In order to take a leading position in the future low-carbon/zero-carbon ship market, the Japanese maritime industry and the Japanese government are investing heavily in the research and development of next-generation alternative fuels such as hydrogen fuel and ammonia fuel, viewing it as an important path for the Japanese shipbuilding industry to re-emerge in the global market.

Last May, Japanese shipbuilders jointly developed the world's first four-stroke ammonia fuel engine, which started land-based experiments and successfully completed stable combustion of ammonia fuel with a mixing ratio of 80%. This is part of the domestically produced ammonia fuel engine and ship development plan in the "Next-Generation Ship" development project launched by the New Energy and Industrial Technology Development Organization (NEDO), under the Ministry of Economy, Trade and Industry in 2021.

This project is jointly undertaken by NYK Line, together with Nihon Shipyard, Japan Engine Corporation (J-ENG), IHI Power Systems, and Nippon Kaiji Kyokai (NK). According to the plan, the partners will develop and operate an inland ammonia fuel tugboat in fiscal year 2024 and develop and operate an ammonia fuel ammonia carrier in fiscal year 2026.

Last October, NYK Line started the conversion work of the tugboat "Sakigake," converting this LNG-powered tugboat to ammonia fuel. It is expected to be completed and delivered in June 2024, and at that time, the vessel will also become the world's first commercially operated ammonia fuel vessel. In February this year, IHI Power Systems delivered the world's first ammonia fuel engine to NYK Line for use on the tugboat "Sakigake" currently undergoing conversion.

In addition to the conversion of the "Sakigake," in December last year, the above-mentioned companies signed a construction contract for a 40,000-cubic-meter ammonia fuel liquid ammonia carrier, which will be built by Japan Marine United (JMU)'s Ariake Works and equipped with domestically manufactured engines. This is the world's first medium-sized ammonia fuel liquefied gas carrier (AFMGC), and is expected to be completed and delivered in November 2026.

The main engine will use an ammonia dual-fuel two-stroke engine developed by Japan Engine Corporation, and the auxiliary engine will use an ammonia dual-fuel four-stroke engine developed by IHI Power Systems. The main engine achieves a 95% ammonia fuel mixing combustion ratio, and the auxiliary engine, which powers the generator, has an ammonia fuel mixing combustion ratio of at least 80%, with the entire ship's greenhouse gas emission reduction rate reaching or exceeding 80%.