Numerical Analysis of Hydrocarbon Adsorption and Desorption Behavior on NOx Selective Reduction Catalysts Using Supplemental Hydrocarbon under Diesel Transient Condition

NOx reduction was estimated on various axial distributions of precious metal through a catalyst based on a numerical model of diesel NOx selective reduction by HC which takes into account the adsorption and desorption of HC. We had a qualitative agreement with the experimental results. We can obtain the behavior of distributions of adsorbed HC amount by our calculations, which we hardly obtain by experiments. This is a very useful information for a design of HC-SCR systems. We have developed a new method of optimization of diesel selective NOx reduction systems with a supplemental HC to improve the efficiency of HC-SCR.