Hello all!
Ammonia is considered as one of the most promising fuels for the long-term decarbonization of the maritime sector. As its adoption is still at a very early stage, numerous studies and papers have addressed concerns regarding its safe use, the availability of bunkering infrastructure, and the design of propulsion engines and auxiliaries. However, I have not yet come across any study exploring the impact of ammonia combustion emissions and ammonia slip (unburnt ammonia) on public health and air quality.
A recent study by MIT highlights this issue. According to the study, ammonia combustion generates nitrous oxide, a greenhouse gas about 300 times more potent than carbon dioxide. It also produces nitrogen oxides (NO and NO₂, collectively referred to as NOₓ) and can result in unburnt ammonia slipping out, forming fine particulate matter in the atmosphere. The nitrous oxide would persist in the atmosphere for over 100 years while the particulate matter may cause serious respiratory issues. Even the greenest ammonia generates nitrous oxide (N₂O) and nitrogen oxides (NOₓ) during combustion as well as ammonia escaping unburnt. In conclusion, while ammonia has the potential to be a nearly carbon-free maritime fuel, new emissions regulations are necessary to mitigate its impact on air quality and human health.
Wong_2024_Environ._Res._Lett._19_084002.cleaned.pdf (3.3 MB)