Setting Course, an ABS Podcast

Ammonia as a Maritime Fuel

• American Bureau of Shipping • Season 1 • Episode 3

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Ammonia is one of several alternative fuels being evaluated by the maritime industry to help achieve net-zero emissions by 2050. While ammonia has the potential to be a zero-carbon fuel or a carrier for hydrogen fuel, the chemical is extremely toxic and has stringent handling requirements.

On this episode of Setting Course, Rene Laursen, ABS Director of Global Sustainability, joins host John Snyder, Managing Editor of Riviera Maritime Media, to discuss ammonia’s potential, its challenges and its path to broad adoption as a maritime fuel.

Key Points

  • Ammonia is being considered as an alternative fuel for shipping to achieve carbon neutrality by 2050.
  • It can be produced from renewable sources and does not emit carbon or CO2 when combusted.
  • Scaling up renewable electricity and, thus, green ammonia production is a challenge to meet the industry's fuel needs.
  • The cost of producing green ammonia is expected to be two to three times more expensive than traditional ammonia.
  • Ammonia can be used as a fuel in both four-stroke and two-stroke engines, but the combustion technology and pilot fuel requirements differ.
  • Storing ammonia on board ships is already taking place, and there are different tank systems available.
  • Safety measures and training are necessary due to the toxicity of ammonia.
  • The shipping industry is expected to see an increase in the use of ammonia as an alternative fuel in the coming years.

Guest
Rene Laursen serves as Director of Sustainability for ABS, leading the ABS Copenhagen Sustainability Center. In his current role, he supports shipowners in selecting the best technologies and fuel mixes for their fleet.

John Snyder (0:00)  
You're listening to Setting Course, an ABS Podcast. Join us as we navigate the latest trends, developments and challenges facing the rapidly evolving maritime and offshore industries. Catch every episode at www.eagle.org and podcast platforms everywhere. 

Hello and welcome to the show. I'm John Snyder, managing editor of Riviera Maritime Media and I'll be your host. Decarbonization continues to be a focal point for shipping and one of the compelling alternative fuels being considered is ammonia. However, it also has its challenges. Today, we're going to discuss ammonia as a marine fuel and some of those challenges with Rene Laursen. Rene is the director of fuels and technology at ABS. Rene, welcome to the show. 

Rene Laursen (1:00)  
Thank you, John.

John Snyder (1:02)  
So, Rene, let's jump right into it. Tell me a bit about ammonia. Why is it being considered an alternative fuel for shipping?

Rene Laursen (1:11)  
It's quite obvious that shipping is going to be carbon-neutral in 2050. That has just been agreed with within IMO. And we are now targeting solutions within shipping where we're going to use a carbon-free fuel or carbon-neutral fuel. And then the ammonia comes up as an attractive alternative to other carbon-neutral fuels like methanol, LNG that also can be produced without any impact on CO2 emissions, because it does not require any biogenic carbon for production. It comprises just nitrogen and hydrogen in its molecule. And therefore, it can basically be produced from renewable electricity either from solar or from hydropower or from wind. So, in terms of combustion, then there will not be emitted any carbon from the combustion and therefore not any CO2. So when a shipowner has, or is using ammonia on board, he can basically not do any more in order to eliminate the CO2 emissions. So this is why it's getting very interesting for ship owners to use ammonia as a fuel.

John Snyder (2:34)  
Now, you spoke about ammonia being produced from renewable sources, but today mostly ammonia is not produced that way.

Rene Laursen (2:44)  
No, today, ammonia is being produced from either methane or coal in a steam reforming process, where the methane is turned into hydrogen and then CO2 is emitted to the air. Nitrogen has been captured from the air. 78% of the air is nitrogen, so it's actually easy to capture nitrogen for the production of ammonia. The technology for production of ammonia is the Haber-Bosch process and that was invented in 1913 and came in commercial operation approximately 20 years after in 1930. So, this Haber-Bosch process is an old technology which is fully optimized. And this is the same process which is going to be used today in order to produce renewable ammonia based on renewable electricity.

John Snyder (3:52)  
But, of course, one of those the challenges then is getting enough renewable electricity to produce the green ammonia.

Rene Laursen (4:01)  
Yes, and that's the huge challenge is to scale up electricity production. I will say that, if you look around and see what is announced in terms of green ammonia projects, then we have gathered all announcements and found that approximately 130 million tons of green ammonia is going to be produced in 2030 to 2035 and that is a significant amount. If the whole of shipping is going to use green ammonia as a fuel, it will use it should use around 580 to 600 million tonnes per annum. So it corresponds approximately to a little less than a third of what is needed for the total shipping and that will be available probably around 2035-2040 in those quantities.

John Snyder (5:02)  
But of course, it could also be blended. As the fuel becomes available, the green ammonia becomes available, it could be blended as part of a decarbonization strategy.

Rene Laursen (5:18)  
Yes, if you're looking at green ammonia, then the production costs compared to the ammonia we use today, which we call either gray or brown, depending on how it is produced, then the cost will probably be two to three times more expensive in the future. So it will have a big cost impact for the shipowners to use this fuel. And that can be mitigated by using a blend — blend in fossil-based ammonia into the green ammonia. But you can also perhaps use a cheaper alternative, the same fuel which you're using today, which is very low sulfur fuel oil in the beginning and then have intermediate operation on ammonia. So you have a period operating on ammonia and a period operating on very low sulfur fuel oil. Very low sulfur fuel oil is probably a better option compared to gray or brown ammonia. Production of brown or gray ammonia is emitting something like 60% more CO2 than fuel oil. So, to use that as a fuel is really not an alternative, we will just increase the problem that that we are in.

John Snyder (6:44)  
Right so the current ammonia has a worse carbon footprint than very low sulfur fuel oil. 

Rene Laursen (6:53)  
Yeah, that's clear, simply because the Haber-Bosch process and the steam reforming process you're using — that requires energy and that is emitted directly to the air. So, there is an energy loss in this process. If you compare it to using methane directly, compared to steam reforming and Haber-Bosch process, then it's clear that it's much more energy efficient to use this form of energy as a fossil fuel instead of ammonia. Today, ammonia is being used as a fertilizer, it's also been used as a refrigerant in cooling systems on fishing ships and also fish factory. So, it is actually already available on some ships in the engine room and there is codes and regulation in order on how to deal with this ammonia on board ships.

John Snyder (7:55)  
Now, Rene what kind of propulsion technology are we talking about in using ammonia? I see Wärtsilä, for example, has announced availability of an ammonia dual fuel engine in the four-stroke category and WinGD and MAN are discussing their two-stroke alternatives, which will be released in the near future.

Rene Laursen (8:23)  
Yes, this is what we're going to see, first of all. The four-stroke engines, which are coming out from Wärtsilä, as you said, and also the two-stroke engine manufacturers, they will also be delivering engines that can operate on ammonia. The question is what kind of technology should you use for combustion of ammonia. And if you compare to the use of LNG, there's two ways to go there. For engine manufacturers, in order to develop those engine systems is a so-called Otto-cycle type of combustion that can also be used for combustion of ammonia. It has some disadvantages, but it certainly also have some advantages. The overall engine system will be less efficient with the Otto-cycle, basically. 

Otto-cycle is where you pre-mix air and fuel and you compress it within the engine system. And then you ignite it when you have the piston in top dead center position. The alternative is a diesel cycle. And here you have a high pressure of the fuel being delivered to the engine and you inject it while you have your piston in top dead center position and then you have ignition with pilot fuel or a spark and you'll get a much cleaner combustion without any fuel slip with a diesel process. 

The disadvantages with a diesel process is that you need a high pressure of the fuel being delivered to the engine. For ammonia, we are talking about the 600 bar supply pressure and you will have a need to develop pumps that is delivering this kind of supply pressure for the engine system and they have a cost. So, the alternative is to go to the Otto-cycle, which only require pressure in between five to 15 bar supply pressure, and that's a lot cheaper to develop pumps and compressors for that purpose. 

On the other hand, you can expect with the Otto-cycle that you get more fuel slip and for ammonia this is an issue because ammonia is toxic and you cannot emit that from the exhaust gas system. So, you will need to eliminate that in the exhaust gas system. And that can be done by applying an SCR system and SCR is also technology that can remove NOx in the exhaust gas system, but it works on using ammonia and if you know how much ammonia slip you have in your sources gas system then you can turn this ammonia into a NOx reduction. So, with Otto-cycle, it has a cost impact on the after treatment where the diesel cycle has a cost impact on the supply side. And the diesel cycle you will not have any fuel slip from the combustion — it will be a clean combustion with very limited amount of ammonia in there. So there’s not needed any after treatment for the ammonia slip.

John Snyder (11:42)  
Rene, you had mentioned pilot fuel and ammonia has been kind of characterized as a lazy fuel. Could you talk a little bit about how much pilot fuel you potentially could need?

Rene Laursen (11:55)  
Ammonia burns very, very slowly, so it's actually best suited for engines operating with low RPM and that is particularly interesting for two-stroke engines that operate today with an RPM around 70-100 RPM. If you look at the medium-speed engines, they're operating in perhaps 250 RPM. They're both suited, but two-stroke is better suited because they have a long period where it can burn the fuel. In order to ignite ammonia, ammonia has a very low cetane number. A cetane number is a fuel's ability to self-ignite. So, it would need support from the pilot fuel and the expectation is that the pilot fuel for the (two-stroke) engine will be in the range of 5%. Perhaps in the beginning will be slightly higher until engine makers find out how to optimize it. But there is test results that indicate that 5% can be reached. For engines operating with a high RPM, it's more difficult to reduce the pilot fuel. So, for medium-speed engines operating in range of 200-300 RPM, we will see a high amount of pilot fuel, perhaps 10-15 or even 20% pilot fuel will be needed for those type of engines.

John Snyder (13:28)  
So to reach that zero-emission goal, owners will have to look at perhaps fuels such as bio-diesel or something, some kind of biofuel.

Rene Laursen (13:41)  
Yes, they cannot reach 100% by using ammonia solely. I think also in the future we are going to look at well-to-tank emissions and also well-to-wake emissions. We're looking at the release of CO2 during production, transportation and use of ammonia. So, we're looking at the full chain there. And it's difficult even for green ammonia to reach the absolute zero. There will still be a little amount of CO2 that will be released. And also for combustion, you will have the impact there from the use of the diesel. This can be biodiesel, or it can also be synthetic diesel that can be used to ignite the ammonia. I would say the reason for using ammonia instead of let's say synthetic diesel is that the ammonia is more simple to produce. It does not require the same amount of energy, renewable energy, in order to produce an energy unit of ammonia compared to an energy unit of diesel. Diesel will probably be using something like two to three times as much energy for production of the same energy amount. So it's a matter of limiting the amount of pilot fuel as much as practically as possible.

John Snyder (15:13)  
Now, Rene what about storing ammonia as compared to traditional marine fuels?

Rene Laursen  15:19  
The storing of ammonia onboard ship is already taking place today. There's 20 million tons of ammonia which has been transported in LPG carriers, and there are 700 LPG carriers out there, which are suitable for transporting ammonia. So, tank systems for carrying ammonia is readily available today. These are the so called Type C tanks, it's a tank which is designed for a pressure of up to 20 bar. If you store ammonia in those tank systems, it will remain liquid in ambient condition up to 45 degrees (Celsius). The alternative is to use a Type A tank and these are tanks which are non-pressurized. It is designed for pressure of 0.7 bar. It is supported by a secondary barrier. And it's storing the ammonia in a liquid form at minus-33 degrees (Celsius). It does not take up the same amount of volume as the Type C tank. So, in terms of volume efficiency, it's a more attractive solution. But on the other hand, you will need something to deal with boil-off gas coming from ammonia. Bcause you store it at minus-33 degrees (Celsius), there is no cooling in the tank system, there's insulation. So it will keep on boiling and this ammonia there in a way performs — it has to be reliquefied and sent back to the tank system. It seems to be the most attractive solution for the bigger ship types because it's a cheaper tank solution and it does not take up the same amount of space as the Type C tank. 

John Snyder (15:39)  
So there's potentially some additional capex in investing in some kind of re-liquefaction technology. 

Rene Laursen (17:25)  
Yes, it will have a relatively big impact on the capex or the investment the shipowner is putting into a new ship design. You will need to have appropriate tanks for ammonia, you need to have a fuel supply system that is delivering ammonia to the engine system, you will need a bunkering system so you can bunker ammonia, and you really need a vent system — and all this is added cost for the ship, for the shipowner. The same also with the engine system. Designing an engine that is able to operate ammonia will not make the engine system cheaper. We will expect that there is a cost increase. What we see now is that it is expected to cost approximately 50% more than a conventional fuel oil engine. So, all in all, it is a significant amount in first cost that the shipowner will have to have to invest in order to get ammonia fueled ship.

John Snyder (18:28)  
And not only that, you're looking at increased costs, opex costs, because of projected price anyway of green ammonia.

Rene Laursen (18:36)  
Yes, when we come to 2050, then all the ammonia fuel is going to be a green ammonia and they will have an impact on the opex costs, perhaps two or three times the cost we see today. So, it will set a new standard for how we are going to design the ship. All the devices that can improve the efficiency of the ship, I would expect that those are going to be implemented on the ship design. We can we can expect to see that there's going to be wind-assisted propulsion system is going to be applied on top of the ship simply because that this can give some reduction in fuel costs. There's a better business case for this. There's also systems like air lubrication systems, small bubbles that have been injected below the hull of the ship that can lower the friction of the ship and give some improvement. The waste heat recovery system, which is using the heat in the exhaust gas system. And there are different other technologies which can give small improvements — paint and rudders, propellers — all those type of solutions we will expect to see implemented in new ship design.

John Snyder (19:56)  
So, energy efficiency — absolutely critical.

Rene Laursen (20:02)  
Yes, that's for sure. It's going to be the engineers’ centuries, the next two or three centuries here, because we are going to design the ship in a completely different manner. The business case moves when you have fuel costs increasing by a factor of two or three compared to today. And then suddenly, a lot of technology, which is on the on the edge, as mentioned before, they are becoming attractive to implement in new ship design.

John Snyder (20:35)  
Now, one of the challenges we haven't discussed actually is the toxicity of ammonia. And of course, the safety of seafarers. I was wondering if you could talk a little bit about that.

Rene Laursen (20:49)  
Yeah, ammonia is heavily toxic. It is transported today 20 million tonnes on board LPG carriers, and this is taking place over the last 60 years and with good results. There's very few incidents with ammonia leaks and casualties. But if you have a just a low amount of ammonia being released on board the ship, if it's above 300 ppm, it can have a critical impact on your health. So, this should absolutely be avoided. Ammonia in small quantities — five ppm is not dangerous and even up to 50 ppm is not dangerous. And it's easy to smell. And the recommendation is if you can smell ammonia, then move away from the area there. But if it's a bigger leak, then the seafarers, they will not be able to smell it immediately. We need to have a safety system that detects leaks. We need to have implementation of a system that can turn ammonia vapor, ammonia liquid into a water ammonia solution, which is not dangerous, and then send that to a drain system. All these systems are today being developed and are going to be implemented. The target for many of the projects where ABS is involved in is to collect ammonia vapor in case you have a leak there, and then get that away in a safe manner and store it in a dedicated tank system. The same also with liquid leaks. And then on board there's supposed to be also protection system for those who work there and in case there is a leak and they have to do maintenance on that part. Then there will be mask, gloves, glasses and suit which is able to withstand liquid ammonia, so they can be sure that there's no harm for them.

John Snyder (23:08)  
So, there's still quite a bit of work to do on ammonia, but things are progressing.

Rene Laursen (23:13)  
Absolutely. We see already now if we look in the market, there's a number of projects, which has been announced, which is going to be where the ship is going to be fueled by ammonia as small LPG carriers and as a bigger LPG carriers, the VLGC carrier up to 80-90,000 cubic meters and there is actually also a very large ammonia carrier on the way to be designed up to 150,000 cubic meter. So this will be coming. Shipowners have seen the market for ammonia is going to be present in the future. The areas where green ammonia is going to be produced is areas where there is a lot possibility of building up a lot of renewable electricity production in using solar cells and wind turbines. And these areas are desert areas. Its remote areas — that is Western Australia, it's Africa, it's Saudi Arabia, Oman, Chile. There's a lot of land there where you can put up these solar farms for production of ammonia. The thing is that when you have produced it, you have to transport it away in shipping and ship owners to have seen this market is coming. We from ABS have estimated that within the next 10 years, there will be a need for approximately 100 to 200 VLGCs just for transporting the additional ammonia coming from this production

John Snyder (25:03)  
So, quite an exciting market then. 

Rene Laursen (25:05)
Yes, absolutely. 

John Snyder (25:08)  
Now, Rene, with just a few minutes left in our podcast, I was wondering if you had any final thoughts for our listeners? 

Rene Laursen (25:16)  
Yes. You can say that if you're looking at ammonia, why when it's toxic? Why is that needed actually to use that on board a ship? I'd say in shipping, it's a relatively small amount of people who will be in touch with ammonia. So, training those is — it's a task which is possible to do within a relatively short time. The crew on board will need training dedicated to be able to handle with a different situation on ammonia. So, we'll say shipping is more or less ideal for ammonia. I cannot see ammonia being used in cars in the future — there will simply be too many people there is going to deal with ammonia. But on board ships, it seems to be able to work. And then it does not require any biogenic carbon for production of ammonia. Biogenic carbon is a limited source. We see it already, today, that the price on biogenic carbon for production of different chemicals is going up. Ammonia do not need that. So it is expected that ammonia is going to be, let's say, the cheapest alternative fuel out there in the future. 

John Snyder (26:39)  
Well, thank you for that, Rene, and thanks for joining me today on Setting Course, an ABS Podcast.

Rene Laursen (26:46)  
Thank you very much for letting me participate.

John Snyder (26:49)  
Thank you for joining us today on Setting Course, an ABS Podcast. If you're interested in learning more about today's topic, or listening to more episodes, visit www.eagle.org