Green ammonia projects have gained significant traction, with several megaprojects in the Mena region such as Neom and Green Energy Oman aiming to export their product to Europe as a hydrogen carrier.

But the cost of cracking and potential efficiency losses could undermine the case for conversion back to hydrogen, potentially leaving direct use of green ammonia as the more attractive option for some producers, according to speakers at the recent World Hydrogen Mena conference in Dubai.

“The lowest-hanging fruit with [green] ammonia production is displacing grey ammonia, so that is the first thing you do,” said Jonathan Carpenter, vice-president, new energy services at UK-headquartered services firm Petrofac, at the event. He notes that ammonia could also be used as a shipping fuel or in power generation as these sectors seek to decarbonise.

“What is important is to have security of supply” Hoolwerf, Port of Amsterdam

“Only after you have done all of that would I consider starting to crack ammonia,” he argues, estimating that the entire process of producing hydrogen, converting it to ammonia for transportation and cracking the chemical back to hydrogen has a 20–25pc net efficiency.

And green ammonia production faces challenges, Carpenter notes. In addition to sizing the renewables and storage components of the plant to ensure the lowest cost of production, getting consistent hydrogen flows into the plant is another major consideration for designing green ammonia projects—which may be difficult owing to the intermittency of renewable energy input.

“Keep in mind that ammonia cannot be switched on and off every day,” agrees Syed Naqvi, CTO of India’s Acme Group. “The Haber Bosch process works on a certain temperature and pressure, and it is not possible to build it up every day, so you need to maintain a continuous supply of green gases and energy for producing ammonia.”

Liquid hydrogen

On a separate panel, Manfred Schuckert, head of automotive regulatory strategy at truck manufacturer Daimler, notes that the firm is looking into imports of liquid hydrogen as “the full supply chain will be done better once we are on the mass market.”

“We are not really looking into a single network of hydrogen stations; we are really looking throughout Europe, and so we have longer transportation distances to transport the hydrogen. And then once you look into consumption of 6–8t per refuelling station, then the natural way is more on the liquid side,” he argues.

Schuckert notes that, while the firm is targeting €4–6/kg ($4.3–6.4/kg) hydrogen at the pump, this price is unlikely to be achieved “at the beginning”, with regulatory tools such as the EU’s renewable energy directive driving initial take up.

Consultancy Aurora Energy Research calculated earlier this year that liquid hydrogen produced in Morocco and shipped to Germany could cost €4.58/kg—lower than alternative methods such as liquid organic hydrogen carriers (LOHC) and ammonia along the same route, estimated at €4.68/kg and €4.72/kg respectively.

Ruled out

One port into Europe has already decided not to focus on ammonia as a vector for hydrogen imports.

“Port of Amsterdam focuses on several non-ammonia pathways, most notably liquefied hydrogen, LOHCs and [solid hydrogen carriers],” Mark Hoolwerf, deputy director of port authority Port of Amsterdam International, tells Hydrogen Economist.

“Ammonia as a cargo is fairly non-existent in the port of Amsterdam,” he says, adding that the port of Rotterdam has infrastructure in place to supply its existing ammonia demand centres. He notes that ammonia is particularly tightly regulated for ports such as Amsterdam, which are close to population centres.

The port last October signed a memorandum of understanding with tank storage operator Evos and technology firm Hydrogenious to jointly establish an LOHC dehydrogenation plant as well as related storage and handling facilities by 2028.

While port of Amsterdam does not have any dedicated ammonia facilities, it has storage terminals that handle diesel and other oil products. “One big advantage we see for LOHCs is you can repurpose those facilities—besides the dehydrogenation plant, no further investment is needed to handle LOHCs. The port is, likewise, well-positioned for the handling of liquefied hydrogen,” Hoolwerf says.

However, Hoolwerf is less willing to write off ammonia as a carrier based on cost. “Looking at price estimates for different vectors, it can vary between researchers and can be based on assumptions that have a fairly large share of unknown factors,” he says, pointing to the cost of ammonia cracking as having a large degree of uncertainty.

Similarly, he notes that the potential cost differential between imports and local production—such as Dutch developer Hycc’s planned 100MW and 500MW electrolyser projects—is less of a concern in the near term. “What is important is to have security of supply, to have sufficient hydrogen to keep fuelling the industries that are already here and that we serve in the hinterland.”

The port of Amsterdam also has an existing CO₂ pipeline, which currently serves the horticulture sector, but could be expanded to provide feedstock for the production of e-fuels, as the port has several sources of biogenic CO₂. “That is really one of the big advantages we have as a port: nearly all of the ingredients are available, we just need green hydrogen.”

---

Author: Polly Martin