Catalytic Mechanism Of Diesel Particulate Filter Regeneration Based On Cerium Fuel Additives

It is well known that Diesel Particulate Filter(DPF) is an effective way to control particulates emission. But it has not still been widely applied because of the problems that the filter is easy to heat damaged during regeneration, high energy consumption and higher fuel quality requirements when operating. Fuel-borne catalyst makes particulates deposited inside the porous wall regenerate by the active metal component in fuel, which can reduce the particulate ignition temperature to about200℃, and also reduce the peak temperature of the regeneration process. Thereby it can lower the consumption of regeneration energy and avoid thermal damage of the filter. In this paper, a fundamental study on catalytic regeneration mechanism of cerium additives within DPF is performed, which has the important theory signification and engineering value.This paper is supported by National"863"Program (2008AA11A116) and National Natural Science Foundation of China (50876027). The kinetic model of particulate catalytic regeneration based on cerium additives has been researched and verified using numerical simulation and experiment. Finally, PSR model of software CHEMKIN was applied to investigate the impact of CeO2on ignition temperature and oxidation rate of the particulate. The main research work and innovations are as follows:(1) Based on the structure, properties and catalytic nature of CeO2, and physical and chemical processes of heterogeneous catalysis within DPF, contact between catalysts and soot particles has been considered to be the determinants about particulate oxidation rate.(2) Based on the existing kinetic model of regeneration and a geometric parameter about contact between catalysts and particulates, the kinetic model of particulate catalytic regeneration has been derived. Furthermore, the model is reasonable by validating the predict results.(3) Applied the software CHEMKIN to research catalytic regeneration of particulate, the simulation results show that CeO2can reduce the ignition temperature of particulate and increase the oxidation rate by the function of storage and release oxygen, quality and dispersion of CeO2have a significant impact on the catalytic properties.