MITSUI O.S.K. Lines and Mitsui E&S Machinery, a developer of large maritime engines, signed a memorandum of understating with MAN Energy Solutions to buy an ammonia-fuelled main engine.

MAN Energy Solutions has said it is aiming to develop a two-stroke ammonia engine by 2024, followed by a retrofit package for existing maritime vessels by 2025.

Ammonia is considered by some a front runner in terms of clean maritime fuels, as it does not emit carbon dioxide when burned.

MOL has said it would strive to achieve net-zero greenhouse gas emissions by 2050. The company is to begin deploying net-zero oceangoing vessels in the 2020s.

Ammonia as a marine fuel has also attracted the attention of other major shipping lines.

Maersk in March joined a group of companies in taking part in a feasibility study on ship-to-ship ammonia bunkering at the Port of Singapore.

The study is to cover the entire end-to-end supply chain of ammonia bunkering, including the development of a cost-effective supply of green ammonia.