The world's first pure ammonia-powered demonstration vessel completed its maiden voyage in Anhui province on Saturday, marking an important step toward the industrial use of ammonia fuel in shipping.

Ammonia, a compound of hydrogen and nitrogen, has emerged as a promising alternative to petroleum for the maritime industry because of its nearly carbon-free nature — its complete combustion produces only water and nitrogen. The international shipping industry currently accounts for about 3 percent of global greenhouse gas emissions.

Companies in several countries, including Japan and Norway, have explored the viability of using ammonia fuel to help decarbonize shipping. However, challenges remain, including safety concerns, combustion instability and emissions of nitrogen oxides.

The ammonia-powered vessel, named Anhui, was jointly developed by the Institute of Energy of the Hefei Comprehensive National Science Center and its subsidiary, Shenzhen Haixu New Energy Co. Its maiden voyage took place on Chaohu Lake in Hefei, capital of Anhui province.

The vessel achieved stable and complete combustion of pure ammonia fuel, with nearly zero carbon dioxide emissions and effective control of nitrogen oxides, according to Wu Dianwu, deputy director of the hydrogen energy and ammonia application research center at the institute.

The Anhui is equipped with a 200-kilowatt high-stepped gas internal combustion generator, two 100-kilowatt propulsion motors and a twin-propeller propulsion system. It has a full load capacity of 50 metric tons and a rated speed of 10 knots.

Wu said the research and development team made several technological breakthroughs over the past two years, including plasma ignition and sustained combustion of pure ammonia, as well as efficient catalytic cracking of ammonia to produce hydrogen.

Wang Junli, secretary-general of the Chinese Society of Naval Architects and Marine Engineers, said the voyage marks a major step toward building a clean and low-carbon energy system for waterborne transport.

Wu added that the vessel's successful voyage also demonstrates the potential for ammonia-hydrogen fuels to be widely used in marine and land transport, as well as in industrial boilers and fuel cells.