The “Anhui,” the world’s first pure ammonia-powered demonstration vessel, has successfully completed its maiden voyage in Hefei, located in eastern China’s Anhui Province. This milestone marks a significant advancement in sustainable shipping practices. With ammonia being a key feedstock in the chemical industry, its high energy density and carbon-free combustion–resulting only in water and nitrogen emissions–position it as a promising fuel alternative for the decarbonization of maritime transport.
In recent years, shipping companies from nations such as Japan and Norway have heavily invested in developing ammonia-powered vessels. According to a 2021 report from the International Energy Agency, ammonia could fulfill approximately 45 percent of global shipping energy demand by 2050, especially in a scenario aimed at achieving net-zero emissions. However, there are challenges to overcome, including ignition difficulties and instability during combustion.
The Anhui was collaboratively developed by the Institute of Energy within the Hefei Comprehensive National Science Center and Shenzhen Haixu New Energy Co., Ltd. This innovative vessel features a 200kW high-speed gas internal combustion generator, two 100kW propulsion motors, and a twin-screw propulsion system, with a full load capacity of 50 tonnes and a maximum speed of 10 knots. Researchers have addressed several key technological challenges, including those related to the ignition and sustained combustion of pure ammonia fuel, as well as efficient catalytic processes for converting ammonia to hydrogen.
The successful outcomes of the maiden voyage included stable combustion of ammonia fuel, minimal carbon dioxide emissions, and effective management of nitrogen oxides. Wang Junli, secretary-general of the Chinese Society of Naval Architects and Marine Engineers, highlighted that the vessel’s successful journey represents a pivotal step towards a cleaner, low-carbon energy framework for maritime transport. With further advancements, the applications of pure ammonia engines could become significantly broader, supporting China’s ambitions for reducing carbon emissions.