GCGF: Why Ethanol Deserves a Seat at the Alternative Bunker Fuels Table

(Manifold Times) While green marine fuels have had strong industry backing, ethanol’s benefits haven’t been highlighted enough for maritime use. Chris Chatterton makes his case on why that should change. -- Chris Chatterton, Maritime Advisor of Global Centre for Green Fuels (GCGF), believes ethanol should have a seat at the alternative bunker fuel table and he shares with Singapore-based bunkering publication Manifold Times why it deserves to be part of the conversation:

The Global Centre for Green Fuels, or GCGF, is a non-profit global think tank headquartered in Singapore. We were established in 2024 to accelerate the adoption of sustainable fuels across maritime, aviation, and land transport. Our work focuses on enabling real-world deployment of low-carbon solutions through data-driven policy, technical validation, and strategic industry collaboration. We help stakeholders – from regulators to shipowners – navigate decarbonisation challenges with practical, scalable fuel strategies.

MT: As its maritime advisor, why do you think ethanol should be considered as an additional maritime fuel?

Ethanol presents a pragmatic pathway to decarbonise shipping. It’s widely available globally, competitively priced, and can be used with existing methanol dual-fuel engine platforms – often with minor re-calibration. Importantly, ethanol offers very low lifecycle emissions, whether derived from crops, waste or lignocellulosic biomass. Ethanol’s clean combustion profile also helps reduce local air pollutants like SOx and PM (particulate matter). Given the urgency of the IMO’s 2030 and 2050 decarbonisation targets, ethanol stands out as an immediate, scalable, and practical solution.

MT: What’s the current status of the push on ethanol following the document submission, highlighting the use of ethanol as a marine fuel, from Brazil and IBIA at IMO MEPC 83?

That submission was a critical milestone. It called for three main actions: a) inclusion of ethanol in the GESAMP LCA Working Group for lifecycle assessment, b) a request for ISO to develop a marine fuel standard for ethanol, and c) updates to the IGF Code to reflect ethanol-specific safety and operational differences from methanol. The submission was well received and is now being processed through relevant sub-committees like CCC and MSC. GCGF is supporting this by coordinating technical input and promoting pilot demonstrations and engine testing.

MT: With lots of focus on LNG, methanol, ammonia and hydrogen as part of the future marine fuel mix, why do you think there hasn’t been much talk on ethanol and what do you think needs to be done to ensure it is part of the alternative fuel pool?

MT: As the IMO’s IGF Code already includes methyl/ethyl alcohols as marine fuel, are there specific advantages in using ethanol vs methanol? What are the specific risks of ethanol, compared with methanol?

While it’s true that ethanol has a low flashpoint similar to methanol and as addressed in the IMO IGF Code, it’s important to note that methanol’s flash point, already in use as a marine fuel, is slightly lower. So low flashpoint alone isn’t a disqualifier, it’s a characteristic that must be managed through proper standards and safety protocols. Importantly, ethanol has a significantly lower toxicity risk than methanol, making it safer for crew handling, spill and salvage scenarios.

Ethanol has lower energy density than fuel oil, but higher than methanol, which makes it slightly more efficient too. Therefore, what is needed is a robust, ethanol specific ISO standard that accounts for its unique properties such as water miscibility, energy content, and ignition characteristics. Importantly, ethanol also carries significantly lower toxicity risks than methanol, making it safer for crew handling and spill scenarios.

Modern dual-fuel engines designed for methanol and electronically controlled – like the Wärtsilä W25, W32, the Everllence (MAN) LGI series and several WindGD models – can be re-calibrated to ethanol with minimal hardware changes. It’s mainly a software calibration and minimal adjustments in the fuel supply system. Several leading OEMs have confirmed this compatibility, and we’re now working with engine OEMs to initiate formal testing and trials. The real opportunity lies in making ships “alcohol-ready,” giving owners flexibility between methanol and ethanol based on cost, supply, and route-specific decarbonisation goals. READ MORE