It’s versatile and abundant and you can store and transport it. Ammonia is seen by many as a future source of clean energy for the maritime industry. But for ammonia-fuelled shipping to become a reality, more work needs to be done.
Easier to store
The shipping industry is responsible for about 3% of global CO2 emissions.
A report from the IEA says that to hit zero emissions by 2050, hydrogen-based fuels - including ammonia - should account for 30% of maritime fuel.
There is no silver bullet for zero-carbon marine fuels, but ammonia is easier to store than its green fuel competitor hydrogen - it is also a safer way to transport hydrogen itself.
Japanese shipping and logistics company NYK Lines and IHI Power Systems are developing the world’s first tugboat that runs on ammonia.
"We have to achieve net zero by 2050," says Yokoyama Tsutomu, Senior General Manager at NYK Line's Green Business Group. "We have to eliminate greenhouse gas. Ammonia is the most advantageous solution because firstly it is zero emission and does not emit greenhouse gas and we already have some experience in transporting ammonia."
There are significant design challenges with ammonia as it is toxic to humans and aquatic life, but NYK is working to mitigate these concerns.
"Safety is our most important and fundamental top priority item," says Mr Yokoyama. "Currently what we are doing is, a physical assessment is in process which is held with Japanese governmental body, the Japanese coastguard. We are identifying the possible risk and also delivering the solution as well."
Made from hydrogen and nitrogen, ammonia is already widely used as a fertiliser and in cleaning products but the production process at the moment is far from clean.
Cleaning up the ammonia production process
At the Fukushima Renewable Energy Institute, Japanese engineering company JGC along with AIST used electricity produced from renewables to make so-called ‘green ammonia’.
Cleaning up the ammonia production process could have significant benefits.
JGC plans to build a green chemical plant in the Fukushima region to make the most of locally produced renewable energy as part of the drive to cut the CO2 currently produced by ammonia and eventually go even further.
"The amount of CO2 is 1 to 2% of world emissions," says Kai Mototaka, Group Manager at JGC Corp Sustainable Solutions. "But ammonia can be used for another sector, a new market for energy, power generation and shipping so we can reduce a huge amount of CO2, not just 1 to 2% but much more.
"We expect maybe 10 to 20% of whole CO2 emissions because it is used for the energy sector."
And, that's exactly what is in the pipeline in Hekinan.
In a world first, JERA, Japan’s largest power generator, will trial a project at its coal-fired thermal plant to use 20% ammonia, with the aim of running fully on ammonia by 2050.
Once operational the power plant will produce roughly enough electricity to serve the neighbouring city of Hekinan, a city with a population of around 70,000.
Ammonia is already used at the plant, so scientists have been able to lean on existing technology and knowledge.
Crucially, however, a new supply chain will have to be created, using traditional ammonia along with carbon capture - so-called blue ammonia.
"We have to make a new supply chain outside of Japan," says Takahashi Kenji, General Manager at JERA's Decarbonisation Section. "We are thinking blue ammonia and also we will develop green ammonia, but green ammonia is still in the development stage and the volume is relatively small."
Ammonia has significant potential, and while challenges - including the cost - remain, it is hoped that the price of renewable electricity will continue to fall making green ammonia a viable clean fuel for the future.