Ammonia engine tests show up to 95% emission cuts: Report

Ammonia is re-emerging as a strong contender in shipping’s clean fuel race, with fresh breakthroughs and industry milestones pushing it back into the spotlight. China recently carried out its first green ammonia bunkering operation, while Japanese companies are preparing for landmark ammonia bunkering projects in Singapore, the world’s busiest refuelling hub, by 2027.

Adding momentum, the Global Maritime Forum’s Getting to Zero Coalition has released new findings showing the significant decarbonisation potential of ammonia-fuelled engines. Full-scale trials indicate that ships running on ammonia could slash tank-to-wake emissions by 90–95%—well above engine makers’ initial expectations.

The report, however, cautions that more real-world data is needed to validate these results. Independent monitoring will be critical to building confidence in ammonia’s greenhouse gas profile.

Ship operators interviewed by the GMF said early adoption will be cautious, with ammonia likely used only 25–50% of the time on first-generation vessels to gain operational experience. Initial ships are also not expected to rely on ammonia during manoeuvring or port stays, leaving questions about how quickly full-scale adoption can be achieved.

In addition, the GMF noted that blue ammonia—produced from natural gas with carbon capture—is expected to dominate supply through at least 2030, meaning the path to near-total emissions reduction will be gradual rather than immediate.