Activation energy of Douglas fir char gasification by carbon dioxide

Abstract

The activation energy of Douglas fir wood char gasified in carbon dioxide was determined. Activation energies were found for chars that had been pyrolyzed in nitrogen at 600, 750, and 900°C. A thermogravimetric analyzer provided the weight versus temperature data used to obtain the activation energies. The Coats-Redfern integral method of kinetic analysis was used to extract the activation energies from the data. This method can be used to obtain an activation energy from a single weight versus temperature trace for a constant heating rate. An overall apparent activation energy of 723 ± 60 kl/mole and a natural log of the pre exponential factor of 68.8 ± 6.2 was determined from the data collected for all three chars. The different char preparation temperatures did not appear to affect the activation energy.