How turbocharging can make a difference in the hunt for future fuels

A turbocharger cartridge
We caught up with Raphael Ryser, Senior Expert Turbocharging and Engine Technology at ABB Turbocharging, to discover more about the part turbochargers can play when switching to alternative fuels.

At a time when we’re seeing more and more extreme weather events around the world, the need to embrace decarbonization to tackle climate change has never been more important. Switching from fossil fuels to alternative fuels such as hydrogen, ammonia and methanol will play a huge part when it comes to decarbonization and sustainability, but there are plenty of challenges along the way.

Raphael Ryser, Senior Expert Turbocharging and Engine Technology at ABB Turbocharging, recently presented at the Rostock Large Engine Symposium, discussing the value of turbocharging for combustion and performance when using alternative fuels on large engines. In this first of a two-part series, we caught up with Raphael to discover more about the part turbochargers can play when switching to alternative fuels, the challenges we’re likely to face over the coming decades, and why it’s so important that we act as quickly as possible.

Sustainability and decarbonization has been high, if not top of the agenda for many businesses. What’s your own personal view on the shift to a decarbonized solution?

I think there is no way around it, and there are two reasons for this. Number one is, of course, global warming; we’ve seen what has happened over the past 150 years and it doesn’t look very promising. Just look at all the weather situations which we’ve had in the past 20 years which we haven’t seen before, and the need to make a change becomes ever more apparent.

The second reason is the fact that fossil fuel reserves are also limited, and at some point when you have to start deep sea exploration it gets incredibly expensive. It also gets a lot more difficult to actually get reserves out of the ground, and from this point of view I also think it’s necessary to switch to alternative sources. The earlier we can do this, the less urgent it actually is, as we’ll have more time to think about suitable solutions. This is something we know from everyday situations – without urgency, you’re in a position to get better results.

So how does this tie in with your presentation at Rostock?

The main findings I wanted to present was the effect that fuels have on turbocharging, and what we can expect if we make a switch to alternative fuels. The second part of the presentation was the kind of solutions we’d have to look towards for the adapted conditions.

This could include the need to change certain ancillaries on an engine – with the injection systems and turbochargers most affected, and in certain cases the after-treatment systems will need looking at. We’ll also need to look at certain tuning parameters on the engine, but this is not so difficult.

Engine designers may need to make certain modifications or implement new layouts. It also depends on the actual fuel; changing from one liquid to another could require a change in specifications – perhaps different materials will be needed, for example. It all depends on the starting point as to the direction we need to take.

Turbocharging can play a critical role because it helps to control the combustion of fuels. This was one of the motivations for my research. As I read the papers from other companies and universities, I came to the conclusion that there was a gap, and that devices could be designed in a slightly different way if engineers had more freedom.

Which fuels are we more likely to adopt?

At the moment, that’s a difficult question to answer and it depends on the engine size and application. From what we currently know, hydrogen will be used in certain applications, ammonia is an option especially in marine, and if that doesn’t work then methanol is another alternative. It depends on a few different circumstances.

We already have experience of working with hydrogen, we understand the properties of the fuel but it’s still very much about the application. Depending on the mixture, hydrogen can be easy to control but it can also be very explosive, and you need to find the correct operating window where combustion is stable. That’s where turbochargers can offer support, helping to vary the amount of air that’s mixed with the hydrogen, and providing air to engines is our business. However, the biggest challenge remains with the overall infrastructure, rather than just the properties of the fuel itself.

Artwork depicting alternative fuels, with a container and a wind tunnel

Why is setting up an infrastructure to supply hydrogen, ammonia or other fuels more challenging than storing and supplying fossil fuels?

When considering supply, you need to think about the amounts of decarbonized fuel required – especially when it comes to shipping. A huge amount of fuel is required by the marine industry alone, which means even bigger amounts of those substances will need to be produced. If you want to convert all ships to use methanol, for example, you need to produce the same amount currently produced for other industries as a whole, just to feed the vessels. It’s a similar order of magnitude in the case of ammonia. Hydrogen, in addition, requires much larger volumes than fossil fuels, creating bigger issues when it comes to production and storage.

When you look at such numbers, it will take a long time simply to establish the infrastructure, and this also means you’ll need to find investors who believe in whichever particular technology. One of the biggest challenges is convincing multiple parties to come to an agreement that pushes an individual technology. They may come to a conclusion and push one of the fuels before the others, but at the moment it’s too early to tell, and it also depends on regulation.

It’s necessary that the whole supply chain works together, from ship operators, to regulatory bodies like the IMO, to fuel producers, to build up an infrastructure, otherwise it may not be possible to meet decarbonization and sustainability goals.

Which fuel looks like being the best option for decarbonization?

You need to ask certain questions, such as how the actual carbon content of the fuels should be measured. Is it just the carbon in the fuel itself, for example? Or are you also taking production into account? Look at ammonia – ammonia itself is carbon free, but – at the moment – needs to be converted from natural gas on land. That whole cycle is less efficient than if you just burn methane directly on the ship itself. And this will remain until we have enough regenerative sources to produce the ammonia.

It’s clear that it’s still too soon to champion any particular fuel as a leader when it comes to decarbonization, then, but Rafael has lots of other thoughts about alternative solutions, research and development and the technology required to make the change possible. Check out our second story in this two-part series, as we delve into the topic further.

Image credits: Picturepark/Michael Reinhard