Non-isothermal Determination of the Pyrolysis Kinetics of a Mixture of Olive Residue and Polystyrene

Abstract

Pyrolysis of olive residue, polystyrene and their mixture (1:1 weight ratio) were investigated by thermogravimetry. Experiments were conducted under N₂ atmosphere at four heating rate of 2, 10, 20, and 50 K/min from room temperature to 900 K. The results showed that the thermal degradation temperature range of olive residue was 430–660 K, while that of polystyrene was 580–800 K. In general, we can note that the domains of degradation are well differentiated. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. The maximum degradation temperatures of polystyrene in the mixture were higher than the polystyrene pure. The calculated residue was found to be higher than experimental. These experimental results indicate a significant synergistic effect during pyrolysis of mixture of olive residue and polystyrene at the high temperature region. The kinetic studies were performed using the Friedman kinetic-modeling equation. The overall activation energies were: 165 and 219 kJ/mole for hemicellulose and cellulose, respectively; 180 kJ/mole for polystyrene; and 160, 215, and 166 kJ/mole for hemicellulose, cellulose, and polystyrene in the mixture, respectively. Thus, it has been found that there exists an overall synergy, when two materials were pyrolyzed together.

Keywords:

• kinetic
• non-isothermal
• olive residue
• polystyrene
• pyrolysis