Kinetics of the catalytic thermo-oxidation of asphaltenes at isothermal conditions on different metal oxide nanoparticle surfaces

Thermogravimetry analyses have been employed to study the catalytic effect of different metal oxide nanoparticles on the thermo-oxidative decomposition of asphaltenes at isothermal conditions. Three metal oxide nanoparticles were considered in this study, namely: NiO, Co3O4 and Fe3O4. Results showed that the presence of nanoparticles decreased the activation energy of asphaltenes oxidation and enhanced the reaction rate. It appears that the thermo-oxidative reaction is metal oxide specific. The obtained kinetic data showed that NiO has the highest reaction rate followed by Co3O4 and then Fe3O4, which suggests a change in the reaction mechanism.

Graphical abstractIsothermal conversion for thermal oxidation of asphaltenes at 360 °C without nanoparticles and at 300 °C in the presence of nanoparticles.Figure optionsDownload full-size imageDownload high-quality image (138 K)Download as PowerPoint slideHighlights► Metal oxide nanoparticles enhanced the reaction rate of asphaltene thermo-oxidation. ► The thermo-oxidative reaction is metal oxide specific. ► NiO nanoparticles have the highest reaction rate. ► Differences in activation energy for different nanoparticles suggest different reaction mechanisms.