NO reduction mechanism in microreactor with cantor fractal structure

With the rising emission of NO and particulate matter in vehicle exhaust, the atmosphere is gradually deteriorating and human health is being impacted. In order to reduce the NO emission in automobile exhaust devices, a tubular microreactor with a Cantor structure was studied in this paper. The NO conversion rate and concentration were evaluated by considering the fractal principle, reactant concentration ratio, inlet velocity and channel temperature. Increasing the fractal dimension could promote the mixing of reactants and make the distribution of species concentration in the channel more uniform. When the NO flux at the inlet of the microreactor channel was a constant, increasing the concentration of NH3 could significantly improve the reaction efficiency. Results show that the effect on the reaction results was best when the NO inlet velocity was lower and the NH3 inlet velocity higher. For example, when uNO=0.025 m s−1 and uNH3=0.05 m s−1, the conversion rate of NO was as high as 98%. Porosity had little effect on the reaction results. Through comparison of the NO concentration at the outlet at different channel temperatures, it was concluded that increasing the temperature in the channel is most helpful in improving the reaction efficiency. © 2022 Society of Chemical Industry (SCI).