Ethanol could displace up to 2 billion gallons of marine bunker fuel annually across the world's existing methanol-capable fleet, according to a new assessment from the National Lab of the Rockies.

The lab's report, "Evaluation of Ethanol Use in Marine Shipping," sizes the near-term opportunity at 2 billion gallons "under high-substitution scenarios," drawing on the 112 methanol dual-fuel ships now in commercial operation.

NLR researchers examined molecular similarity between methanol and ethanol. They concluded ship operators could run a large dual-fuel methanol engine on ethanol without operational changes. The lab prepared the assessment with support from Growth Energy and the U.S. Grains and BioProducts Council.

What does the assessment say about engine compatibility?

Robert McCormick, NLR researcher and lead author, framed compatibility as the central technical hurdle. "Ethanol has compatibility with methanol infrastructure, and scalability could make it suitable for vessel applications," McCormick said in a release.

The report also credits ethanol with:

• Lower emissions than conventional marine bunker fuel
• Lower toxicity than methanol or conventional fuel
• Greater energy density than methanol
• Reduced environmental impact in spill scenarios

How does marine demand translate to U.S. corn margins?

Ryan LeGrand, president and CEO of the U.S. Grains and BioProducts Council, tied the marine finding directly to domestic agriculture. "Expanding marine fuel use could create additional demand for ethanol while providing another market for U.S. corn growers," LeGrand said.

The 2-billion-gallon ceiling would create a new export channel at a time when domestic blend-wall constraints cap growth in E15 and E85 markets. Producers along the Mississippi, Illinois and Ohio river corridors — the export hubs for corn-based ethanol — would capture the most basis upside if maritime demand materializes.

Ocean-terminal access already routes product to global fuel markets, and new maritime contracts would lock in grind demand outside the seasonal gasoline-oxygenate cycle.

Who backed the report?

Growth Energy and the U.S. Grains and BioProducts Council supported the NLR assessment, according to a release from both organizations. The two groups represent U.S. ethanol producers and corn growers and have lobbied for years to expand ethanol markets beyond motor fuel.

What stands between the assessment and adoption?

The report urges collaboration between ethanol producers and shipping companies on demonstration projects, fuel-blending specifications and classification-society approvals. The 112 methanol-fueled ships provide a ready fleet for pilot deployment, NLR said, provided fuel-price spreads between ethanol and methanol favor substitution.

Adoption will hinge on three factors:

• Port-side bunkering infrastructure for ethanol at major shipping hubs
• Carbon-intensity certification under international maritime rules
• Long-term contracting between producers, traders and shipowners

For U.S. ethanol plants, even partial capture of the 2-billion-gallon scenario would open a market segment that has historically tracked U.S. gasoline demand. Marine use would decouple a portion of grind from the seasonal swings of the driving season and tie ethanol pricing more closely to international freight rates and bunker fuel benchmarks.

Corn basis at river terminals would track the new demand channel alongside export sales to gasoline-oxygenate markets. The report's spill-impact comparison could weigh on classification-society approvals as port-state regulators review ethanol's environmental profile.