In brief: Maersk is testing ethanol, a fuel the US already makes and exports in bulk, on container ships built to burn methanol.
Implications:
Supply: A second fuel for methanol-ready ships could mean more low-emission sailings for you to buy, on more lanes.
Claims: Ask which fuel and feedstock sit behind any low-emission sailing you pay for, because EU rules give crop-based fuel no credit.
Rules: The global method for scoring a ship fuel’s emissions is still open, and the IMO votes on its framework Dec. 4.
The News
Maersk loaded about 5,000 tonnes of bioethanol onto the container ship Maersk Halifax in Singapore, the largest ethanol bunkering done in a single operation to date, the Maritime and Port Authority of Singapore said. The fuel went aboard at PSA’s Pasir Panjang Terminal while cargo was being worked. The port authority will use the results to decide whether its methanol bunkering rules and meters can apply to ethanol.
Maersk Halifax is the first container ship in Maersk’s fleet converted to run on alcohol fuel. Before that, the newer Tangier Maersk took on 100% US corn ethanol from the producer POET in Houston, the first ship-to-ship ethanol fueling of a deep-sea container ship in the US. Both followed blend trials that began in 2025 on the Laura Maersk, first 10% ethanol with 90% e-methanol, then a 50-50 mix.
Maersk still calls these tests. It said wider use depends on fuel supply, regulation and whether ports and crews are ready. Its head of energy markets, Emma Mazhari, said in Singapore that no single fuel can decarbonize shipping on its own. Maersk is also trialing a rotor sail.
Why It Matters
Ethanol gives methanol-ready ships a second fuel while green methanol is scarce, though more of the fuel behind low-emission sailings could come from corn.
Ships waiting on fuel: Carriers have ordered ships that can burn methanol, and the container orderbook is at its highest share of the fleet since 2008, while green methanol plants have been slow to come online.
Little change needed: Those engines can take ethanol with little or no change, so the ships can burn something other than oil.
Supply on hand: The US already makes and exports ethanol in bulk, so the low-emission sailings carriers sell could grow.
Zoom In
The US already ships abroad about as much fuel ethanol as the world’s methanol-ready ships could burn.
A study by the National Laboratory of the Rockies, done under the direction of the ethanol trade group Growth Energy, estimates the existing methanol dual-fuel fleet could use nearly 6 million tonnes, or about 2 billion gallons, of ethanol a year if it switched fully, which the study treats as a ceiling rather than a forecast. The US exported 2.2 billion gallons of fuel ethanol in 2025, by our math from Energy Information Administration data. Even so, ethanol has no marine fuel specification yet, and the ISO standard for one is still being written.
Whether an ethanol sailing counts as low-emission depends on what the ethanol was made from and whose rules apply. Under FuelEU Maritime, which covers ships calling at EU ports, biofuels made from food and feed crops take the same emission factor as the most carbon-intensive fossil fuel, so corn ethanol earns a ship nothing on a European lane. Maersk and the port authority described the Singapore fuel as ISCC-certified bioethanol and did not name its feedstock.
Outside Europe, the IMO’s Net-Zero Framework, which would charge ships for emissions and reward cleaner fuels, was delayed a year, and the lifecycle rules that would score each fuel from field to tank are still being worked out.
Peer Insights
Some shippers buying low-emission sailings write a lifecycle cut into the tender and leave the fuel choice to the carrier.
Amazon, IKEA, Nike and Patagonia: pooled their demand in the Zero Emission Maritime Buyers Alliance, whose first tender required at least a 90% lifecycle cut and went to Hapag-Lloyd for waste-based biomethane between Singapore and Rotterdam in 2025 and 2026. Its second tender went to Hapag-Lloyd for e-methanol and North Sea Container Line for e-ammonia, with members committing for three to five years from 2027.
Volvo Cars: put almost 15,000 containers on Maersk’s ECO Delivery Ocean in 2023, which ran on biodiesel made from waste, with each saving confirmed by a certificate audited by PwC.
What’s Next
Nov. 23 to 27: The IMO’s technical group on greenhouse gases meets, with lifecycle fuel accounting still on its list.
Dec. 4: IMO members vote on adopting the Net-Zero Framework, which could not apply before 2028.
2030: FuelEU’s cap on the emissions of fuel used on EU voyages tightens to 6% below its reference level, from 2% now.
Photo: Wzhkevin, CC BY-SA 4.0, via Wikimedia Commons
