TEMPERATURE PROFILES AND WEIGHT-LOSS IN THE THERMAL-DECOMPOSITION OF LARGE SPHERICAL WOOD PARTICLES

The thermal decomposition of relatively large particles of pine wood has been studied. By use of spherical particles of different sizes (2-5.6 cm in diameter), the experimental solid conversion values and the temperature at different points of the solid are analyzed for different heating rates of the system. The experimental results have been compared with those calculated with a simple model, which involves the solution of the heat and mass balances and the kinetic equations, using experimental values as boundary conditions. A good agreement has been obtained for particles up to 4 cm in diameter. For larger particles the mass transfer resistance inside the solid and the existence of secondary reactions may acquire an appreciable importance.