Analysis on chemical reaction kinetic model of ASC for a diesel engine aftertreatment system
PANG Bin
YAN Caicai
LIANG Hengshan
LÜ Zhihua
DAI Ziyang
Abstract：To meet the increasingly stringent requirements for NOx emissions and NH3 slip,based on the reaction mechanism of ammonia slip catalyst(ASC)combined with reactor tests,the conversion process and products of NH3 over ASC are analyzed.By introducing inhibition factors related to NO concentration in the reactions of NH3 oxidation to N2 and N2O to distribute the NH3 oxidation pathways,an ASC kinetic model is established and simulated,and verified by bench tests.The simulation results show that when the reaction temperature is lower than 350 ℃,the main products of NH3 oxidation are N2 and N2O;the volume fraction of generated N2O reaches the maximum at 250 ℃.When the reaction temperature exceeds 350 ℃,the selectivity of NH3 oxidation products increasing NOx emission.Reactor tests and bench tests indicate that the ASC kinetic model can predict the volume fraction of NOx and N2O downstream of ASC,and the prediction error is no less than±10％for NH3 oxidation conversion rate.The model can accurately reflect the experimental characteristics of ASC.
Keywords：diesel engine aftertreatmentASCNH3 oxidationvolume fraction of NOxvolume fraction of N2O
Publication Date：2026-02-28
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：8( 38-44,55 )