Investigation of gaseous ammonia for NOx control by SCR on an experimental basis

My dissertation argues which of the two reducing agents, urea or pure ammonia, is better suited for reducing NOx emissions in Marine SCR applications. While the question might seem straight forward, there are several upsides and downsides to them both. What proves a challenge with marine diesel engines are the low exhaust gas temperatures, making it a brain twister to reduce NOx across varying engine loads by any respectable amount. Still, theoretically, pure ammonia should be able to do this, or? To put this claim to the test, a micro scale SCR system is designed and built by a team of competent individuals, including myself. A series of NOx reduction tests are then carried out under conditions similar to a diesel SCR process, using gaseous ammonia as reducing agent. While results are varying it is confirmed that pure ammonia does indeed perform well at low temperatures. NOx reduction rates are impressive considering the system is not optimized with regard to dimensioning. Results are presentative but with potential for improvement