Wärtsilä has begun combustion trials using ammonia fuel. The aim is to explore the potential to use ammonia instead.
In the test, ammonia was first injected into a combustion research unit to investigate its properties. The tests will be continued on dual-fuel and spark-ignited gas engines. These will be followed by field tests in collaboration with ship owners from 2022, and potentially also with energy customers in the future.
Ammonia may offer a carbon-free fuel option. Although it is derived mainly from fossil sources today, in the future ammonia’s greenhouse gas footprint can be nearly eliminated if it is produced using electricity from renewable sources.
However ammonia has a number of properties that have to be managed. It ignites and burns poorly compared to other fuels and is toxic and corrosive, making safe handling and storage important. Burning ammonia could also lead to higher NOx emissions unless controlled either by aftertreatment or by optimising the combustion process.
Wärtsilä says it is investigating several future fuels, including synthetic methane, ammonia, hydrogen and methanol, because internal combustion engines can be adapted for different fuels. Dual-fuel or spark-ignited engines can burn liquified natural gas – from fossil, biomass or synthetic sources – while diesel engines can run on liquid biofuels, biodiesel or e-diesel.
Ammonia’s greatest potential is that it can be stored as a liquid at room temperature and as such has a higher energy density than hydrogen which must be stored as a gas since the boiling point of H2 is -252 degrees C. Because of its toxicity and corrosivity, the best application for NH3 is likely to be as a fuel cell feed to power electric motors in shipping. While it can burned, this will produces NOx which is not good for the environment