Modeling and Simulation of a Low Temperature NOX Adsorber Catalyst
Forrest Liu, BASF
Forrest Liu, Xinyi Wei, Steve Steeley, Manish Sharma
Typical diesel exhaust systems containing Selective Catalytic Reduction catalysts (SCRs) are effective at reducing NOX emissions once catalysts are warmed up. With the upcoming Bin-30 emission regulations in North America and the Euro VI/VII regulations in Europe/Asia along with the complicated RDE test cycle in Europe/Asia, there is a need to reduce NOX emissions during the cold-start part of the test cycles (first 40 seconds or so). Therefore, there is a need to develop a catalyst which can capture NOX at low temperature and release it at higher temperatures.
This poster describes the development of a model for the Low-Temperature NOX Absorber (LT-NA) catalyst, which works along with the SCR catalyst to improve the system level NOX conversion performance over the test cycle. This catalyst model describes the adsorption and desorption processes for NOXand HC at low temperature, and the oxidation of HC, CO and NO with oxygen and/or NO2. The model has been validated with lab reactor steady-state and engine FTP cycle tests. The model can be used to optimize the development of LT-NA based emission after-treatment systems. This model has been developed to be used with CATSIMTM, which is the BASF proprietary modeling software.