The Study of Fuel Cracking Effect on NOx Absorber Catalyst; the Diesel NOx Reduction System

A NOx absorber and a fuel cracking catalyst were combined to investigate whether this could increase the low temperature activity of a NOx absorber system. Before engine exhausted gas tests, the activity and properties of the NOx absorbing catalyst were examined by simulated gas and temperature programmed desorption. Diesel fuel cracking catalysts were designed to maximize the hydrogen productivity. From the hexadecane reaction experiments for these catalysts, it was found that the hydrogen generation amount was significant even at 200°C. Engine bench test results with the diesel fuel cracking catalysts confirmed the improvement of NOx removal efficiency. In case of high NOx capacity with prolonged regeneration interval condition showed the best results. It reflects the importance of optimization of the NOx absorber and the pre-oxidation catalyst, the regeneration strategy.