Ammonia: Höegh Autoliners Cuts Through the Grey Area
Confusion over new fuels will not be helped by the fact that each one has a good and bad version. The science on grey ammonia, grey methanol, and palm oil biofuel show that these are probably worse for the planet, if adopted, than unfettered continuation of fossil fuel consumption. Conversely, green methanol, green ammonia and biofuel made using genuine wastes and residual products could create a substantial dent in production and consumption of fossil fuels. For this reason, clarity on which fuels shipping lines intend eventually to use is vital.
Höegh Autoliners is set on ammonia, CEO Andreas Enger explained, and is making a commitment to the fuel on which its peers are stopping short. “Ammonia is more scalable and will be cheaper than methanol, full stop,” Enger said. “We don't really want to take a strong position on green versus blue… [but] we have no intention of using grey ammonia. We might end up using it for testing.
“We would be happy … if mass balance is organized through certificates allowing us to swap the molecules. We would be happy to do that. But if it's using these vessels to scale grey ammonia consumption – no, we would not do it.”
Speaking several weeks before the verdict of IMO MEPC 83, Enger highlighted that green fuels, which are currently lacking, would be made available “...if there is a regulation in place that stimulates the demand and incentivises the shift from fossil fuel into green fuels.”
“This did not start as a mission to save the world – it started with needing new vessels to renew the fleet… figuring out what kind of vessel you have to build to make it sustainable in a 30-year expected lifetime. Chinese people are not buying EVs to save the world, they’re buying because they are cheaper. That’s why it’s so important that people actually create the technology that makes it.”
For this, the MEPC 83 outcome would be “absolutely key,” Enger said. “The decarbonisation of shipping will not happen because we build vessels like this – it will only happen if our customers are incentivised by regulation and market forces. We are not choosing the fuel on our vessels, customers are.”
After a divisive MEPC ending in a weak compromise, Enger is liable to be disappointed with the outcome. “Green energy, solar power in the right places in the world is coming down to a price level where it's totally feasible. But it will not happen as long as it's absolutely free to emit carbon,” Enger added.”
Image courtesy Höegh AutolinersTo Fight Tomorrow’s War
One of Höegh’s most forward-thinking measures concerns the inclusion of ammonia-capable tanks on its newbuilds. Despite much buzz throughout the market over supposedly ammonia-ready vessels, the term is nebulously defined at best. But the Aurora-class’ fuel tanks can be used both for LNG and ammonia, without requiring a retrofit.
This necessitates a highly advanced tank design. As one MAN ES expert explained in a recent conversation with Maritime Reporter, other requirements of ammonia lie with piping, the fuel feed system into the engine, and exhaust after-treatment for NOx, which ammonia combustion is expected to produce in far larger amounts than with other fuels. “The difference is the top end injection valve and stuff on the engine. So it's some small parts of the engine, and the piping,” Enger confirmed.
But in a field where some vessels are being designated ‘ammonia-ready’ merely by allocating space in their blueprint for a theoretical future ammonia tank, having one already fitted is quite the achievement. Enger said the presence of a technologically advanced ammonia-capable fuel tank foregoes the hardest aspect of retrofitting ammonia on a vessel and, he believes, makes Höegh’s Aurora-class vessels the most deserving of the ‘ammonia-ready’ accolade. The materials chosen for these tanks must not only withstand the corrosiveness of ammonia, but also the extremes of temperature and pressure which LNG handling entails.
Image courtesy Höegh Autoliners
“We went through the entire retrofit scenario and figured out the most difficult thing to do something about is the tank,” he explained. “Because ammonia has a higher density, it is heavier, and you need different structural strength in the hull, stability, different materials.
“The risk of ammonia in the engine room is, from a safety point of view, fairly manageable. The risk lies in the tank and during bunkering, where you have potential for large leakages.”
Enger admitted to Maritime Reporter that bunkering was a matter of some concern. “Ammonia is a toxic commodity that has to be taken very seriously,” he said. “Personally, I believe that bunkering is the riskiest aspect of operating on ammonia.
“It’s not creating a new fundamental risk that is new to shipping or to major ports… if it was impossible, you would have big issues with agriculture; with ocean fisheries that use ammonia for cooling their products. [But] any kind of sloppiness, any mishap with ammonia will get nuclear attention.”
Asked about Höegh’s strategy for refuelling, Enger suggested that the company may opt for bunkering operations in ports further away from cities, rather than at typical bunkering hubs, many of which are surrounded by dense urban populations. Any handling mishap would be met with an uncompromising response from Höegh, he explained. “I think we will need to be very specific about the ports where we bunker ammonia. If something goes wrong, we will seal the tanks and we won’t go there again.”
Image courtesy Höegh Autoliners