Kinetics of the catalytic combustion of diesel soot with MoO3/Al2O3 catalyst from thermogravimetric analyses

Catalytic combustion of diesel soot was performed over a 15-wt.% MoO3/Al2O3 catalyst in a thermogravimetric analysis (TGA) system, at distinct heating rates and particulate concentrations. Kinetic parameters were then estimated for several experimental conditions, based on a first-order kinetic model and on the numerical integration of the differential mass balance equations. The estimated values of activation energies lie between 139 and 163 kJ/mol, in accordance with published data for similar systems. The analysis of the parameter estimates shows that the so-called compensation effect is a mere consequence of parameter correlation, which can be easily removed through reparameterization of the Arrhenius equation. Finally, it is shown that the proposed kinetic model provides suitable fits for the available experimental data. Besides, it is shown that thermogravimetric analysis, with simultaneous parameter estimation, can improve the statistical significance of the obtained results and lead to better understanding of the analyzed process.

Graphical abstractCatalytic combustion of diesel soot was performed over a molybdenum catalyst in a thermogravimetric analysis (TGA) experiment. Based on a first-order kinetic model, kinetic parameters were estimated for several experimental conditions, providing a suitable adjustment of the available experimental data. The analysis of the estimates of parameters shows that the so-called compensation effect is a mere consequence of parameter correlation, which can be easily removed through reparameterization of the Arrhenius equation. Finally, it is shown that thermogravimetric analysis, with simultaneous parameter estimation, can improve the statistical significance of the obtained results and lead to better understanding of the analyzed process.Figure optionsDownload full-size imageDownload as PowerPoint slide