Kinetics and thermodynamics of microalgae residue oxidative pyrolysis based on double distributed activation energy model with simulated annealing method

Non-isothermal thermogravimetric analysis (TGA) at four heating rates of 10, 20, 30 and 40 K min(-1) under oxidative atmosphere was employed to investigate the characteristics of microalgae residue oxidative pyrolysis. The double distributed activation energy model (DAEM) was used to analyze the oxidative pyrolysis kinetics of microalgae residue and the simulated annealing method was employed for the estimation of the model parameters. The results showed that the double DAEM could describe the kinetic experimental data of microalgae residue oxidative pyrolysis very well whilst the simulated annealing method was effective for determining the kinetic parameters of the double DAEM. The kinetic process of microalgae residue oxidative pyrolysis could be considered as two partially overlapped pseudo-sub-processes. The mean values of activation energy distributions were 179 and 259 kJ mol(-1) for the first and second pseudo-sub-processes. The thermodynamic parameters of microalgae residue oxidative pyrolysis processes at the different heating rate were studied based on the obtained kinetic parameters.

Automated summary

This study investigated the oxidative pyrolysis of microalgae residue using non-isothermal thermogravimetric analysis and the double distributed activation energy model. Results showed that the process could be considered as two partially overlapped pseudo-sub-processes, with distinct activation energy values. The simulated annealing method was effective in determining the kinetic parameters for the double DAEM model.