In general, large ships use a lot of oil. This means that they cause serious environmental pollution. And what accounts for a considerable portion of the pollutants is NOx. They are introducing an ever tighter emission limit on NOx, and starting in 2016, International Maritime Organizatio (IMO) will adopt a drastically strengthened regulation for NOx. Moreover, we need to brace up for expansion of ECA (Emission Control Areas). As there exists a study that has developed a way to improve on the matters, we’d like to share it with you. 

NOx is quite common, as it is included in automobile exhaust. When it comes to ships, however, it’s a totally different story. For NOx discharged from ships is no to be compared in quantity to the gas emitted from automobiles. Increasing efforts are put in addressing such environmental questions, and the spotlight lately given on green IT ships is getting related research in full gear. Thus, people have embarked on initiatives to upgrade to eco-friendly and green ships.

The research team got their hint from the fact that NOx decomposes when it reacts with “AdBlue” urea solution, that is, ammonia. Consequently, the researchers came to think that they could develop a filtering system which would decompose NOx. And they named it SCR (Selective Catalytic Reduction) system and a reaction mechanism.

The research team applied solution polymerization and thereby succeeded in synthesizing WO3 powder with nanoparticles designed for NOx gas sensor. The powder is attached to the sensor to detect NOx, and the sensor automatically sprays “AdBlue” urea solution (ammonia) to the ceramic filter. When this filtering system is installed in the exhaust outlet, the discharged NOx automatically converts to nitrogen and water as it goes through the filter.

Currently, ceramic filter and nano powder have been developed. And by working further on the project, they aim to create a total system that will include detection sensor, control, and injector.