South Korean shipbuilder HD Hyundai Heavy Industries (HHI) has built two ammonia dual-fuel gas carrier vessels.

The two ships will now make their way from HHI’s Ulsan shipyard, on the south-east coast of South Korea, to Exmar LPG France, a subsidiary of Belgian shipping company Exmar, following final outfitting.

Measuring 190 metres long by 30.4 metres wide, the two 46,000m³ ammonia-powered vessels – named Antwerpen and Arlon – are equipped with three cargo tanks designed to enable the safe transport of liquefied gas cargoes such as ammonia and liquefied petroleum gas. 

According to HHI, ammonia will be stored in pressurised tanks onboard the vessels at around 8 bar or in refrigerated tanks at -33°C without the need for cryogenic technology. In liquid form, it has about 1.7 times higher storage density than liquefied hydrogen (-253°C) at the same volume, making it suitable for large-scale, long-distance transport and storage of hydrogen.

Global shipping is responsible for around 3% of the world’s greenhouse gas (GHG) emissions and, with global trade predicted to quadruple by 2050, these emissions will increase rapidly without urgent action. 

The shipping sector is considered hard to decarbonise, as electrifying ships is considerably more challenging than electrifying cars from both a technical and a market perspective. As such, methanol, ammonia and hydrogen are all contenders for use as a green shipping fuel.

According to the International Energy Agency, ammonia is set to account for 8% of marine fuel demand in 2030, rising to 46% by 2050, indicating that demand for ammonia-powered vessels is expected to grow significantly.

As well as the ability to safely transport ammonia, the two vessels are also equipped with advanced detection and mitigation systems, including an ammonia gas detector for real-time leak monitoring and an ammonia purge recovery unit.

The vessels also feature a shaft generator, which produces electricity using the propulsion engine’s rotating shaft, and a selective catalytic reduction system to reduce nitrogen oxide emissions, further enhancing their environmental performance.

Joo Won-ho, head of HHI’s naval and special ship business unit, said: ”It is very meaningful for us to have built the world’s first ammonia-powered vessel, which requires advanced technical expertise. We will continue to strengthen our leadership in the global eco-friendly ship market through ongoing technological innovation.”

HHI is set to deliver a total of eight ammonia-powered vessels from companies including Exmar and Singapore-based trading company Trafigura.

In September 2024, an ammonia-powered tugboat named NH3 Kraken completed its maiden voyage as part of a research project designed to reduce carbon emissions from shipping. 

In March 2025, the UK government announced that all vessels that operate in UK waters and dock at UK ports should be carbon-free by 2050 as part of its climate change goals.