Catalytic combustion of diesel soot: Experimental design for laboratory testing

In order to abate diesel soot particles many catalysts have been studied at several industrial and academic laboratories. However, the comparison of kinetic data obtained with such catalysts is not straightforward, due to the different experimental conditions used in the activity measurement carried out by each research group. Temperature-programmed analysis is the most common technique used to determine catalytic activity for soot oxidation. For a given catalyst, the temperature-programmed oxidation profile depends on variables such as heating rate, oxygen partial pressure, gas flow rate, catalyst:soot weight ratio, type of contact between the catalyst and the soot, and existence of energy and/or mass transfer limitations during the analysis. This work presents a systematic study of the influence of all these testing variables on the TPO profile, and the optimum testing conditions to obtain good reproducibility during the kinetic study. Both experimental and computer simulation results are included to assist researchers in the comparison of results obtained under different experimental conditions.