Clean marine futures: advances in alternative technologies

From significant progress in biofuel technology to the world’s first hydrogen-powered ferry, we dive into some of the most promising sustainable innovations currently taking place in the shipping industry – and what they might mean for its future. 

A problem area for the maritime industry of the near future will be smaller vessels. They run fast, spend a lot of time in port, and cannot rely on vast enormous economies of scale like main-haul ships do – none of which curries much favour with the IMO’s CII regulation. 

But feeders are important for decarbonisation. Most shipowners are reluctant to invest in emerging decarbonisation technology for their largest ships, but in the smaller size brackets, it is a less risky prospect. Samskip, a feeder line not afraid to have a little fun, recently discovered in testing that instead of blending, it is possible to run its vessels entirely on biofuel, with no retrofits. In a situation analogous to that of very low sulphur fuel oil (VLSFO) after January 2020, a non-cap-ex, high-op-ex option has been confirmed to exist.

Though the green-ness of biofuels is sometimes questioned, partner GoodFuels pledges to use only residues and waste, rather than crops, meaning Samskip can boast sailings with a 90% CO2 emissions reduction – no small feat amid an industry which still regards decarbonisation as a mid-term matter. 

Soon after, Samskip partnered up with Langh Ship for further testing aboard 750 TEU feeder Edith. Interestingly, both companies have independently conducted research into carbon capture systems (CCS) as well. Coupling biofuels with CCS brings about the tantalising prospect of a carbon-negative ship – one which, on a well-to-wake basis, actively subtracts atmospheric CO2.

But this might be a step too far for the duo, whose main goal is compliance. “A main advantage of changing to biofuel is that it generates no fossil carbon emissions,” said Laura Langh-Lagerlöf, Langh Ship’s managing director. “Therefore, we are able to comply with the new CII-regulations.”

A pleasant surprise was that each vessel’s engines stayed cleaner and required less maintenance thanks to the cleaner fuel – a valuable cost upside in a market which does little to incentivise the operating cost required. “The feedback from [Edith] has been nothing but positive,” said Langh-Lagerlöf. “Generally, we think that the maintenance costs for the main engine will decrease due to cleaner fuel. We expect less wear on cylinder barrels and the piston ring area, but this can of course be verified only later through experience.”

Project partner GoodFuels expects financing for biofuel will come directly from shippers. IKEA and BMW have already purchased a certain amount through GoodFuels’ GoodShipping scheme, and because biofuel can be blended into a conventional fuel supply, it can be used to offset the CO2 cost of their shipments in particular.

The new generation

For those with less patience for biofuel incrementalism, there are two options: green ammonia, and green methanol. 

Like biofuel, provenance is important, because until now, methanol has been made nearly exclusively via fossil fuels, with associated carbon emissions. But rather than waiting for oil majors to devise them a solution, Maersk has sidestepped them, funding green methanol projects in its bunkering locations. The result is that its newest delivery, a 2100 TEU feeder, can fuel up with methanol right out of the dock. 

“The green methanol market is still in its infancy and frankly we had not expected to be able to secure a maiden voyage on green methanol for this vessel,” said Morten Bo Christiansen, Maersk Head of Energy Transition.

The downside of methanol is that the optics are somewhat murky, given that methanol emits carbon at the funnel – even if it is net-zero from well-to-wake. In the past, it has been challenging to persuade the industry to understand this distinction.

Ammonia seems to mitigate this concern, being zero-carbon both at the manufacturing stage and the funnel. Unfortunately, the situation is more complicated, as ammonia is extremely toxic. A water-seeking chemical, it immediately bonds with water molecules in the eyes, nose and mouth; and in concentrations over 1,000ppm, it is immediately lethal. 

Now imagine spilling a tank of the stuff into the ocean. “A ship sinking with a cargo of ammonia could potentially sterilise cubic miles of ocean,” said Hydrogen Science Coalition co-founder Paul Martin, quoted in Recharge News

Image 6 Incident diagram

For the first time, shipping is able to see what hydrogen looks like in operation (Credit: Shutterstock)

Hydrogen in miniature

Thanks to Norway’s NorLed, shipping is for the first time able to see what hydrogen looks like in operation. It represents a major shift; the comparatively miniscule energy content means it makes little sense to burn hydrogen in an engine, making fuel cells the most likely route. Successfully scaled up, this would be a step-change on par with the shift from steamships to diesel engines. 

But scaling up is the problem. Unless stored either as a liquid at temperatures approaching those of deep space, or in extremely high-pressure gas tanks, hydrogen requires absurd amounts of space, which on a cargo ship would seriously dent its carrying capacity. 

Fuel cells, generating propulsion power with as much as double the efficiency of an engine, are a good way to claw back some of that lost cargo area. A new Norled hydrogen-powered ferry features 200kW of fuel cell capacity. "There are only two parties in the world that use liquid hydrogen as a fuel: Norled with MF Hydra, and the space industry using it as fuel for launches. This says something about the giant technology leap now taken for the maritime industry,” said Norled chief technology officer Erlend Hovland. “After a lot of development and testing, we are now looking forward to welcoming passengers on board for a zero-emissions journey between Hjelmeland and Nesvik.” 

Learn more about the biofuels and technologies discussed in this article at the upcoming 7th Clean Marine Fuel Forum & LNG Masterclass

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Charlie Bartlett is a maritime journalist.