China has completed the world's first commercial ship-to-ship green ammonia bunkering, transferring 1,000 tonnes of the fuel to Belgian shipowner CMB.TECH's newly delivered bulker Mineral Europa at an anchorage off Zhoushan on October 13 and 14.

The operation paired the dedicated bunkering vessel Shenghang Yongle with the 210,000 dwt Mineral Europa, the world's first ammonia-powered dry bulk carrier. For a sense of scale: 1,000 tonnes of bunker fuel is roughly a routine stem for a vessel of that size class, meaning the transfer demonstrated a full commercial operation rather than a token pilot.

The ammonia itself carries a verified green pedigree, according to the parties involved. Producer China Energy Engineering made the fuel at its Songyuan green hydrogen and ammonia project in Jilin province using renewable electricity, then moved it through Nanjing to Zhoushan. The operation brought together China Energy Engineering, CMB.TECH and Jiangsu Andefu Energy Technology — a chain the partners describe as running from renewable production to delivery on board an oceangoing vessel.

What matters commercially is that the word "commercial" is doing real work here. Prior ammonia transfers have been trials or single-party demonstrations; this one established a functioning supply relationship across three companies and two legs of inland and coastal transport.

How big can these transfers get?

Future operations could reach 2,000 or even 3,000 tonnes per transfer, said Li Jingguang, chairman of China Energy Engineering's hydrogen division.

"The offshore ship-to-ship ship-to-ship bunkering model offers remarkable advantages," Li said, pointing to the flexibility of servicing vessels at anchorage rather than alongside a terminal.

Those larger stem sizes, if realized, would bring ammonia bunkering into line with the volumes deep-sea bulkers and tankers expect from conventional fuel suppliers. No timeline accompanied the claim.

What does this mean for decarbonizing bulk shipping?

The timing suits CMB.TECH. Mineral Europa, delivered earlier this month, is now heading across the Pacific to Australia for commercial operations — its first revenue voyage will run on the fuel, not a shakedown on diesel.

CMB.TECH expects 21 ammonia-powered vessels to enter its fleet by 2029, including 18 bulkers. That is a firm order-backed commitment rather than an aspiration, and each of those vessels will need repeated ammonia stems at trading ports. The Zhoushan operation is the first evidence that such stems can be supplied at scale.

For carriers and charterers watching from the sidelines, the calculus remains cautious. Ammonia is highly toxic; Chinese maritime authorities supervised the operation and implemented special safety measures to handle the fuel. Every green transfer to date — this one included — has required regulatory hand-holding that conventional bunkering does not.

The economics also remain unproven. Neither China Energy Engineering nor CMB.TECH disclosed the price paid per tonne, and green ammonia currently carries a substantial premium over conventional marine fuels. Until those numbers surface, the commercial case rests on regulatory pressure and corporate decarbonization targets rather than cost parity.

What comes next?

The Zhoushan precedent gives port authorities elsewhere a working template for offshore ammonia transfer, and gives CMB.TECH a supply anchor as its ammonia fleet grows toward 21 vessels by 2029. Whether the model scales beyond Zhoushan — and whether the green premium narrows — will determine whether this first commercial stem becomes an industry standard or a one-off milestone.