Modeling Transport Phenomena in Selective Catalytic Reductant Catalytic Converter with NH3 as Reductant for NO Degradation

In the current study, reduction of nitrogen oxide from exhaust gas in the presence of NH3 as reductant on selective catalytic reductant (SCR) impregnated catalytic converter was simulated using Comsol© software. Mass transfer (one-dimensional) and heat transfer (three-dimensional) governing equations were taken into account to model the unsteady state behavior of the catalytic converter. Modeling results of reaction rate indicated good agreement with the experimental data. Results showed that the cumulative conversion exceeded 98 percent for both NO and NH3 components in the outflow gas emitted from the converter. In addition, temperature distribution graphs showed that the exhaust gas temperature varied from 450 K at the converter inlet to 550 K at the outlet. According to the results, the temperature tolerance inside the converter was less than 20 °C. Moreover, radial temperature gradient was sharper than axial one because of lesser energy accumulation in the direction of the convective flow.