Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1197997 | Journal of Analytical and Applied Pyrolysis | 2011 | 8 Pages |
Abstract
Thermogravimetric measurements in air of fir wood impregnated with diammonium phosphate in the concentration range 2-20% and heating rates between 5 and 20Â K/min show the existence of three sequential stages: wood decomposition, induction and char oxidation. The additive causes an anticipation in the decomposition stage up to about 100Â K, a reduction in the maximum rate up to a factor of three and an increase in the charred solid residue from about 30 to 60%. The total duration of the induction and oxidation stages is also increased. The experimental curves are interpreted by either a three-step mechanism (one reaction for each stage) or a seven-step mechanism (three reactions for decomposition and two reactions for the induction and oxidation stages). The estimated kinetic parameters are independent from the heating rate but vary with the diammonium phosphate concentration. However, for both mechanisms, the activation energies of the various steps remain practically constant except for the decomposition of the cellulose component or the decomposition step, depending on the complexity of the mechanism.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Carmen Branca, Colomba Di Blasi,