A project that would research how to reduce nitrous oxide emissions from the combustion of ammonia has been selected by Japan’s national research and development agency, “NEDO”.
Ammonia is a compound gas at room temperature composed of one nitrogen atom and three hydrogen atoms giving it the formula NH3.
It is attractive as a potential marine fuel as it is carbon free and can be made using renewable energy, hydrogen sourced by splitting water with electricity and nitrogen from the atmosphere. However, combustion leads to the production of nitrous oxide (NO2) which is a powerful greenhouse gas in and of itself – it is about 300 times more warming than carbon dioxide.
The Japanese companies, Hitachi Zosen and NYK therefore note that reducing NO2 emissions is essential to realise an ammonia-fuelled ship through the development and popularisation of nitrous oxide reactors.
Hitachi Zosen is said to have a “strong track record and know-how” in catalyst technology, including in the development of a marine vessel system for removing nitrous oxides. Hitachi Zosen is said to be developing catalysts and equipment to reduce NO2 in marine two-stroke engines. A two-stroke engine is an engine that burns once per rotation (one reciprocation of the piston) and is characterised by having a small number of parts.
NYK plans to install the Hitachi Zosen-developed reactor on an ammonia fuelled ship that is scheduled to be delivered in November 2026. NYK will conduct safety and performance verification on demonstration voyages and class society Class NK will carry out safety verification of the reactor and basic research on the development of international guidelines.
