Based on initial results, the tests will be continued on both dual-fuel and spark-ignited gas engines. These will be followed by field tests in collaboration with ship owners from 2022.
‘The first tests have yielded promising results and we will continue to optimise combustion parameters,’ said Kaj Portin, general manager, Fuel & Operational Flexibility, Wärtsilä Marine.
‘This is an important step in making sure that Wärtsilä can provide the engine and fuel systems that ship owners need, whichever fuel they choose in the future.’
Ammonia is a promising, carbon-free fuel as shipping explores how to fulfil the International Maritime Organization’s vision of reducing greenhouse gas emissions from shipping by at least 50% by 2050.
Although ammonia 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.
Engines, fuel supply and storage
The tests are the latest step as Wärtsilä aims to develop a complete ammonia fuel solution comprising engines, fuel supply and storage. The company is working with ship owners, shipbuilders, classification societies and fuel suppliers to learn more about system and safety requirements, as well as fuel composition, emissions and efficiency.
Wärtsilä is developing ammonia storage and supply systems as part of a project to install ammonia fuel cells on Eidesvik Offshore’s supply vessel Viking Energy by 2023.
The company has also gained significant experience with ammonia from designing cargo handling systems for liquid petroleum gas carriers, many of which are used to transport ammonia.
Regulatory and class rules needed
Ammonia has a number of properties that require further investigation. 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. A regulatory framework and class rules will need to be developed for its use as a marine fuel.
Wärtsilä is investigating several future fuels, including synthetic methane, ammonia, hydrogen and methanol, with a view to providing complete flexibility across engines and the fuel chain. Internal combustion engines can be adapted to burn any fuel. Dual-fuel or spark-ignited engines are already capable of burning liquified natural gas - from fossil, biomass or synthetic sources – while diesel engines can run on liquid biofuels, biodiesel or e-diesel.
Wärtsilä has extensive experience in converting engines to other fuels, including diesel to dual-fuel, as well as engines capable of burning methanol and volatile organic compounds from crude oil cargoes. The modularity of modern engines means that conversions can be made with a very limited exchange of components.