Publication Date



School of Engineering and Computational Sciences


Engineering: Mechanical


SCR, Selective Catalytic Reduction, NOx, Urea


Computer-Aided Engineering and Design


Aqueous Urea used in Selective Catalytic Reduction (SCR) Systems undergoes three sequential processes that result in ammonia being produced to reduce harmful NOx emissions: Water evaporation, Urea sublimation, and Urea decomposition into ammonia and isocyanic acid. While these phases can be simplified by modeling the Urea as pure water, accuracy is sacrificed to do so. In order to make SCR modelling both accurate and simple, this project set out to find an equation that could represent all three processes. Simulations were run in ANSYS and Particle to generate a set of data, then an empirical equation was created to model these results. The final equation accurately models the evaporation and sublimation phases of Urea in SCR Systems. The decomposition process was not incorporated into the equation but will be the subject of future work.