The conversion fills a supply-chain gap FKAB says has held back ammonia as a marine fuel.

• Shenghang Yongle, a 5,500 m³ gas carrier, converted into what its designer calls the world's first operational ammonia transport and bunkering vessel
• Vessel holds the first ammonia bunkering class certificate from the China Classification Society (CCS)
• Conversion led by Jiangsu Andefu Energy Development, with design work by FKAB and cargo-handling supplier Gloryholder
• Ship-to-ship ammonia bunkering capability comes on top of existing LPG and vinyl chloride monomer cargo trades

A 5,500 m³ semi-refrigerated and semi-pressurised liquefied gas carrier has been converted in China into what its designer calls the world's first operational ammonia transport and bunkering vessel.

Swedish ship designer FKAB said in a press release that its FKAB Marine Design L21 ammonia carrier Shenghang Yongle can now perform ship-to-ship ammonia fuel bunkering, following a conversion led by Jiangsu Andefu Energy Development with cargo-handling supplier Gloryholder.

The Chinese-flagged vessel has received the first ammonia bunkering class certificate issued by the China Classification Society (CCS).

FKAB says several ammonia bunker vessel projects have reached the design, feasibility, or construction stage, but that Shenghang Yongle is the first to progress into operational readiness.

According to MarineTraffic, the 100-metre gas carrier sailed in the East China Sea from Qinzhou to Caojing on September 6.

Built by China Merchants Shipbuilding Industry's Dingheng shipyard and managed by Shenghang Shipping, the vessel was originally designed as a flexible liquefied gas carrier able to transport ammonia, LPG, and vinyl chloride monomer.

The conversion upgraded it into a dual-purpose vessel capable of both transporting liquid ammonia and delivering it as fuel through ship-to-ship bunkering.

At normal pressure (1 atm), Ammonia gas becomes a liquid around −33 °C.

FKAB says the gas carrier's cargo tanks have a minimum design temperature of −48°C, with two low-temperature reliquefaction systems on board, characteristics that gave the vessel a strong technical foundation for conversion.

Its existing cargo containment and handling capabilities were then adapted to meet the extra requirements of transferring ammonia as a marine fuel.

The work required modifications to the bunkering system, new operating procedures, risk assessments, and safety and emergency-response arrangements addressing ammonia's toxicity, material compatibility, low-temperature handling, and leak detection during bunkering, according to FKAB.

Ammonia is regarded as one of the more promising zero-carbon marine fuels of the future, but has yet to shake industry concerns over its toxicity.

FKAB says the lack of operational ammonia bunkering vessels remains one of the major gaps in the ammonia bunker supply chain, and that converting an existing ammonia-capable gas carrier shows how a practical bunkering asset can be developed from the current fleet.