Kinetics of Soot Oxidation on Potassium-Copper-Vanadium Catalyst

Abstract Combustion of carbonaceous materials such as Diesel engine soot, carbon black and graphite on a potassium-copper-vanadium catalyst supported on α- alumina has been studied. Catalyst characterization by thermal analysis and X-ray diffraction indicates the formation of mixed K/Cu/Cl and K/V/O phases after calcination at 700° C. The presence of KCl has been also detected. Soot combustion experiments show a dramatic effect of the catalyst, burn off temperatures being about 300° C lower than those obtained with thermal combustion. Kinetics of soot catalytic combustion has been investigated in a differential flow reactor. A linear dependence on both soot mass and oxygen partial pressure has been found. Comparable reaction rates with the same dependence on the reactant concentrations have been determined also in the case of carbon black. The apparent energy of activation for the catalytic process is 85–100 kJ/mol. The kinetic equation enables to describe the process of catalytic combustion up to conversions of 50%.