Draft IMO guidelines favour a limited split for methanol and ethanol, File Image. Image Credit: AI Generated / Ship & Bunker

• Draft IMO guidelines favour a limited split, keeping both fuels in one set of guidelines
• Lighter risk assessment for ethanol-only ships not taken up by CCC 12
• IBIA's Edmund Hughes says the two fuels "require different management" and this is now recognised in the revised draft guidelines
• Hughes moderates the regulatory panel at the IBIA Annual Convention in New York, November 10-12

The IMO is favouring a limited split between methanol and ethanol in its safety rules for alcohol-fuelled ships.

Until now the IMO has treated them as one, under interim guidelines issued in 2020 as MSC.1/Circ.1621.

That has made ethanol's rise as a marine fuel a good deal easier since it has been able to follow methanol into the same engines, tanks, and rulebook, with the two fuels also able to be blended in any ratio.

But methanol and ethanol are not the same fuel, and Brazil, with IBIA's backing, had argued that the differences are enough to carry meaningful consequences.

Safety Case

The focus on separating the two "has, in part, been led by Brazil with IBIA's support", Edmund Hughes, who represents IBIA at the IMO, told Ship & Bunker ahead of the meetings.

"This matter is firmly considered a safety issue whereby the properties and characteristics of ethanol and methanol differ to the extent that they require different management to ensure safety risks are effectively identified and mitigated within both the regulatory framework and by those who handle these fuels," he said.

"This is important as both ethanol and methanol are viable alternative fuels for shipping, and as the decarbonisation of international shipping will require all energy sources to be used, their uptake is expected to grow."

CCC Response

A draft revision of the guidelines was finalised earlier this month at the IMO's Sub-Committee on Carriage of Cargoes and Containers (CCC 12) in London, following an intersessional working group the week before, and remains subject to approval.

Brazil did not come away empty-handed, and the draft text says for the first time that methyl and ethyl alcohol fuels are distinguished where necessary to reflect their different hazards.

It cites methanol's neurotoxic effects, the intoxication risk from ethanol, and the way denaturants and other additives can alter either fuel as supplied.

The main practical difference in the draft is a new toxicity provision for methanol alone: a local alarm or visual indication at a vapour concentration of 200 ppm at the entrances to enclosed spaces the crew can readily access, such as fuel preparation rooms.

For bunkering, ships using either fuel would be fitted with a vapour return line so that tanks can be filled without releasing vapour, with new provisions for bunkering stations on open deck, in semi-enclosed spaces, and in enclosed spaces, and new conditions for fuel transfer aligned with the IGF Code.

Fitting the vapour return line is not intended to restrict operations where a truck or shore facility has none, and bunker supply ships remain outside the scope of the guidelines.

Not Taken Up

The more substantive ethanol-specific change proposed by Brazil has not made it into the draft.

That proposal called for a more proportionate risk assessment for ships certified only for ethanol, or for diesel-ethanol blends, with the working group taking the view that there is not yet enough experience with the guidelines to narrow the scope of the assessment.

A proposed table of exposure limits for the two fuels was also left out, on the grounds that the figures could mislead once denaturants are taken into account, with a general warning on the health risks of both fuels added to the introduction instead.

One proposal that would have hit both fuels was rejected as well: a requirement, borrowed from the ammonia guidelines, for emergency escape breathing equipment for every person on board was judged too strict for liquid alcohol fuels.

The draft revised guidelines are due for approval at the Maritime Safety Committee (MSC) in June 2027, and the working group's report shows the text is not yet settled, with an intersessional group to meet again next year and some member states still wanting the methanol requirements loosened, leaving room for further changes before then.

Some delegations pressed for the revision to go for approval this year and were told IMO procedure would not allow it, meaning the first ethanol-capable ships, including a very large ore carrier on charter to Vale due in early 2027, are set to enter service under the 2020 guidelines.

One Ship, Two Fuels

Ethanol is coming as a marine fuel either way, and in Ship & Bunker's reading the draft strengthens the case for building ships able to burn both ethanol and methanol.

With no lighter regime on offer for an ethanol-only vessel, an owner gains almost nothing in design terms by giving up methanol, and keeps the option to buy whichever of the two is the better choice on price or availability.

That option is worth more as ethanol bunker supply turns commercial.

The labels may yet cause some confusion: some engine makers describe their engine able to run on fuel oil, methanol, ethanol, or a blend of the two alcohols as "tri-fuel", while others in the market call the combination methanol dual-fuel.

Hughes moderates the regulatory and policy panel at the IBIA Annual Convention in New York on November 10-12.

For more information on the Convention, click here.