Catalytic abatement technology can reduce NOx emissions from shipping

Emissions of Nitrogen Oxides (NOx) are harmful to both humans and the environment and to reduce emissions, it is necessary to purify exhaust gases. Mathias Magnusson thesis, which he will defend on May 28, shows that catalytic converters can reduce NOx emissions from shipping.

A SCR catalyst that Mathias Magnusson has designed and tested with.

Six years ago, when he began his research on NOx emission control in shipping, it was not really a big issue in the industry or academia.
- When I went through my education here at Chalmers, there was no specific focus on the environmental impacts of shipping. The fact that I was fed with information about environmental problems awakened my curiosity – what about shipping?

He began investigating the SCR (Selective Catalytic Reduction), a catalyst system in which urea is added to the exhaust gas and reacts with the nitrogen oxides over the catalyst to form nitrogen and water. The system has been used on board some Swedish ships for about a decade, but it is still not widely used.
- When I started looking at this, I saw that there was plenty of research done for truck engines and thermal power plants, but not on shipping. International regulations for NOx emissions from shipping have not been so strictly regulated, says Mathias Magnusson.
The international regulations have been developed within the International Maritime Organization (IMO) and it is now discussed within the IMO regarding when the strictest NOx regulation, i.e., 80 percent reduction of NOx emissions, should take effect. For newly built ships the year is set to 2016 or a future date.

One reason the SCR system is still not used to any great extent is that there are doubts as to whether the technology is technically mature, and it's also a cost issue. In his PhD thesis, Mathias tries show that catalytic converters can be a good method to reduce emission of nitrogen oxides. In a chemistry lab, he has examined how well the catalytic converter cleans the exhaust gases at different temperatures, gas concentrations and gas flow rates. Then he has interviewed suppliers and ship owners who have used the technology to find out what they think about the SCR technology. Then he has compiled a large amount of on-board measurements to see how much NOx the catalysts can reduce in reality. Finally, he has designed a SCR catalyst that has been tested at Chalmers. The goal is to examine how additives in fuel, lubricating oil and urea affect the catalyst’s ability to purify exhaust gases from nitrogen oxides.
- This is an important issue, if the fuel sulfur content is too high or if there are impurities or additives in the urea this can influence the catalyst and make it work less efficient. Sulfur is a fantastic universal catalyst killer. The less sulfur, the better for the catalyst, says Mathias Magnusson.

After completing a Master of Science degree from Mechanical Engineering and a Master in Naval Architecture, Mathias Magnusson began as an industrial doctoral student at the Swedish Maritime Administration and he has now been at Chalmers for more than four years. On 28 May, he defends his thesis “NOx Abatement Technique for Marine Diesel Engines; Improved Marine SCR Systems “.
- There are many nice colleagues here and I have had the opportunity to learn many new things. But being a PhD is no bed of roses. There is a lot of experimental research, and – if an experiment work out as planned you get a lot of information to work with for a long time to come, but it takes a long time to fix an experiment so that it works. Sometimes it flows smoothly and sometimes you struggle.


On Friday May 23 Mathias Magnusson will defend his thesis, at Chalmers Lindholmen, house Saga, lecture room Alpha between 10AM and 1PM. The dissertation seminar is open for the public.
Mathias Magnusson, Lighthouse co-financed researcher.