Ammonia as fuel - Risks and considerations

What are the main risks, factors and areas of attention for engine manufacturers and operators involved in ammonia-fueled engines?


Hi @Paraschos.Liadis,

Ammonia is a flammable gas and very toxic. It required a suitable sensing system and safety systems such as proper ventilation and water spray to dissolve ammonia, etc.

Also, ammonia is very corrosive, so associated pipelines, valves, fittings, etc., shall be of certain requirements.

Ammonia as marine fuel might be CO2 and SOx emissions-free. However, might have other ship emissions like NOx and possible ammonia slip. Thus, post-treatment of the exhaust gases may be needed (catalyst and selective catalytic reduction - SCR might apply)


What about bunkering risks??
As ammonia is much more toxic that LNG, do you think that ports near cities will allow to do this ammonia bunker, or will it be necessary to go to ports/moorings far from cities?
For LNG bunkering not all port have clear requirements, and do not let to do it in all moorings.


My consideration with ammonia as a fuel is this. Ammonia has a relatively low calorific value. Which means that you would need much more ammonia to produce the same amount of energy (about twice as much). Which means larger fuel tanks - less space for cargo.

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As per 2020, data there are already special ammonia terminals in

  • 38 ports which export ammonia
  • 82 ports which import ammonia
  • 6 ports both export and import ammonia

These terminals provide a good starting point for an infrastructure of ammonia as a marine fuel.

Ammonia terminals in the Baltic Sea and North-West Europe.

Ammonia terminals in the Mediterranean Sea

Ammonia terminals in the Caribbean Basin and North America

Ammonia terminals in the Middle East and South Asia

Ammonia terminals in Asia Pacific and Oceania

Ammonia terminals in South America and SS Africa

Liquified ammonia can be stored in a compression tank (10 bar) or low-temperature tank (-33.6°C). In comparison to LNG and hydrogen, ammonia refrigerated storage temperature is above the cryogenic conditions of LNG and hydrogen.

Indeed, liquified ammonia has a relatively low volume energy density and requires a 4.1 times larger tank in comparison to conventional fossil fuels which leads to a loss of the transport capacity of the vessel.

Source: Ammonfuel Report– an industrial view of ammonia as a marine fuel by ALFA LAVAL, HAFNIA, HALDOR TOPSOE, VESTAS, SIEMENS GAMESA


Hello Queseasians,

Adding to the discussion the below publication :slight_smile:

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You may also refer to the DNV Ammonia as a Marine Fuel Safety Handbook developed by DNV and other industry stakeholders.

Ammonia as a Marine Fuel Safety Handbook (

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