Investigation of serial reaction kinetics and changes of group compositions of vacuum residues in continuous oxidization

The serial reaction kinetics and the changes of the constituents of Daqing vacuum residue (DVR) and Huansanlian vacuum residue (HVR) have been studied during continuous oxidization at 210–310°C. The experimental results show that at constant temperature the contents of saturate constituents and aromatic constituents of the residues decrease clearly, asphaltenes and toluene insolubles increase obviously and resins increase at first and then decrease gradually during continuous oxidization. The higher the oxidizing temperature, the more remarkable the change of constituent contents. The results of kinetic study demonstrate that the apparent rate constants and the activation energies of various constituents of DVR are 0.01157–2.225 h−1 and 19.91–79.32 kJ/mol, respectively, and those of HVR are 0.003089–0.09928 h−1 and 14.81–55.01 kJ/mol, respectively. The change of vacuum residual group composition during continuous oxidization could be well explained by the kinetic model of the serial reaction presented in this paper and the constituent contents predicted by the model conforming reasonably well with the experimental ones.