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Important step towards sustainable shipping thanks to Ghent University research (Durf Denken article)

At last, a feasible solution for sustainable shipping is on its way. The very first tug running on green methanol, developed by researchers at Ghent University in collaboration with the Anglo Belgian Corporation, is ready to conquer and inspire the maritime world.

Methatug: that is the name of the first tugboat that is powered by green methanol. The ship is already sailing in the port of Antwerp. Finally, a feasible solution to switch shipping to green as well. After all, it is lagging behind; while electric cars are conquering the world, almost 100% of ships still run on fossil fuels.

No smooth energy transition in shipping

The turbulent energy transition in the shipping industry is certainly no secret to professor Sebastian Verhelst (research group Sustainable Thermo-Fluid Energy Systems). The law is an obstacle between technology and reality, together with practical difficulties – which is demonstrated in his years of research into renewable fuel. “The transition to green energy is a difficult process”, says Sebastian. “A number of important factors determine the feasibility: for example, we must be able to produce and stock the energy on a large scale.”

Sustainable, scalable and storable

Sustainable, scalable and storable, those are all key to green energy in other words. Sebastian: “The latter is often forgotten. What’s the use of solar energy if the sun doesn’t shine, or wind energy on days without wind. Fuel can be stored and is available at any time.”

The question is: which fuel? “Many people believe that our future lies in hydrogen or electricity. But the biggest challenge with these is the energy density”, explains Sebastian. “Hydrogen needs ten times more volume for the same energy than diesel or petrol. Electricity as much as twenty times.”

So, hardly realistic choices for heavy cargo ships, as high-energy consumers which require a high capacity. “Imagine that your ship runs on electricity: then you must fill half of it with batteries. Not only does that leave you with less space for cargo, it is also very heavy. You can work it out for yourself, when you know that an electric SUV already needs to transport batteries weighing 700 kg. Cargo ships like that actually require so much electricity that you need the power generated by at least three nuclear plants to recharge the batteries of a single ship.” Therefore, hardly sustainable in fact.

Little storage and limited impact

So, an engine powered by green methanol seems like the solution in the shipping industry. This fuel is sustainable, scalable and storable, and it has half the energy density of diesel. Yet, there are more reasons why the technology from Ghent University is an important milestone in the journey towards a solution for sustainable shipping. Sebastian: “You barely need to change the engine.”

Indeed, the technology is added to the existing motors. The process is called retrofitting. “Most ships serve for thirty years, or even longer. If we wait until they are out of service to replace them, we will be long overdue with our CO2 reduction. These engines can be used immediately.”

Additional benefit: with retrofitting the cost remains low. Not to mention the limited impact on the actual ships and crew. Sebastian: “So the ships get a dual-fuel system: we add a system, but leave the original diesel motor in place. That means that the ship can easily switch to diesel in case of an emergency. The dual-fuel system lowers the threshold for shipping, as an industry that is not always keen to change.”

Methanol based on local biomass

Methanol (CH3OH) is the simplest alcohol, and is a colourless and volatile liquid at room temperature. The great advantage of methanol is that there are various renewable options to produce it.

For example, methanol can be derived from biomass. This methanol is known as ‘biomethanol’ or ‘wood spirit’. You can also produce methanol from green energy: first, you produce green hydrogen and this is combined with CO2, which you can – ultimately – extract from the air. A final option is hybrid production, in which green hydrogen is combined with carbon from biomass.

Yet, there is criticism of the use of methanol because CO2 is released, although that should be put into context, according to Sebastian: “Since we start with carbon from biomass or the air, no ‘extra’ CO2 is released into the atmosphere. It is a question of circular CO2 which means it remains climate neutral.”

Swedish tug run on methanol

The Methatug is part of FASTWATER, the European research programme coordinated by Sebastian.  “Our goal is to make water transport more sustainable, and our efforts began in June 2020.”

Another partner in the project is Lund University in Sweden, where Sebastian is an associate. “In Sweden, we have already launched a pilot boat running on methanol – a boat that takes a pilot aboard a ship. This sails on locally produced biomethanol and already travels distances of hundreds of kilometres. 

The biomass that we use there is black liquor, a by-product from a key sector in Sweden: the wood industry. “We always look at the full picture: everything must come together. What’s the benefit of an alternative fuel if its production process isn’t green?” Other potential green fuels were investigated as well in Sebastian’s department.

But, with the Methatug, the first tug powered by methanol, we encountered a greater challenge: tugs are quite a bit bigger than pilot boats. So they sail with a totally different type and much heavier engine. The Methatug can store as many as twelve tons of methanol as fuel, without compromising space inside or functionality. And if necessary, the engine will also still run on diesel.

And now… targeting a new generation of methanol engines

The switch from diesel to dual-fuel engines is the first step. Meanwhile, Sebastian is working in both Lund and Ghent on research into the next-generation engines, running entirely on methanol. “Once the methanol market is ready, we can produce them on a large scale. That will be within five to ten years”, he announces with confidence.

More information on the FASTWATER project:


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