Ammonia has recently received increasing attention as a potential marine fuel that could drive the decarbonization of shipping. As a marine fuel, it can be used in both internal combustion engines and fuel cells.
In the context of a growing hydrogen economy, ammonia is also of interest as the cheapest way to transport hydrogen over long distances and in large volumes. It is a commodity chemical that is traded and produced worldwide; until now it has been used mainly for fertilizer production.
However, ammonia has so far not been used as a marine fuel. It is a carbon-free energy carrier, but it is also toxic. If ammonia is to be used in shipping, it has to be safe for people and the marine environment.
As explained, ammonia is advisable from the point of view of air pollution control, provided that both climate-damaging nitrous oxide and nitrogen oxide emissions are eliminated, thanks to the SCR catalyst.
In addition, strict safety standards are required to prevent leaks, as ammonia is highly toxic.
“Ammonia as a marine fuel can fully realize its climate protection potential if climate-damaging nitrous oxide emissions from production, transport and combustion are almost completely eliminated,” said Leif Miller, CEO of NABU.
“To ensure this, all greenhouse gases must be included in national and international regulations and prices. In addition, there must be strict safety standards for the use of ammonia as a marine fuel. It is true that the short- and long-term consequences of an ammonia accident are less far-reaching than those of an accident involving heavy oil or diesel fuel. However, the consequences for the marine environment would still be immense. ”
“Ammonia is a candidate for a future marine fuel, as it is a carbon-free post-fossil fuel and therefore likely to be cheaper than other post-fossil fuels,” the study has concluded.
“Due to its risk profile, its use may not be applicable in all segments of the maritime sector, e.g. passenger ships. It is likely that the maritime sector will turn to different post-fossil fuels in the future, depending on the market segment.”
“For ammonia to contribute to near-term emissions reductions in the maritime sector, the pace of engine development and subsequent deployment needs to be increased. In line with the precautionary principle and to incentivize new technologies to avoid all GHG emissions, environmental integrity needs to be ensured through stringent regulations covering all greenhouse gases and especially including N2O.”
Although ammonia is not widely used as a fuel in shipping, investments in ammonia infrastructure are not wasted investments. Ammonia will play an important role in decarbonizing other sectors in the hydrogen economy. Therefore, timely financial and legal promotion of green ammonia production under the necessary environmental and safety requirements would not be considered a wrong decision for climate protection in the future, unlike investments in LNG infrastructure, the study further notes.
Klünder suggested that, in addition to regulating greenhouse gases, the German government should work with the International Maritime Organization (IMO) to ensure the immediate creation of a control zone for nitrogen oxides in all oceans in order to pave the way for completely emission-free shipping.
According to Klünder, this regulation could be initiated immediately at the IMO, as it is a proven measure that is already having an effect in the North and Baltic Seas and in American coastal waters.