Modelling and measurements of the pyrolysis of large wood particles

The influence from structural changes, heat transfer properties of dry wood and pyrolysis mechanism on the pyrolysis of large wood particles were stud ied. Measurements of temperature distribution and mass loss were performed on cylindrical samples of dry birch wood during pyrolysis in an inert atmos phere at 700 degrees C. A model of wood pyrolysis was modified to include s tructural changes. Comparisons of measurements and model simulations show t hat the inclusion of a shrinking model reduces the time of pyrolysis substa ntially. The varying interior heating rate was found to influence the choic e of pyrolysis mechanism. Of four pyrolysis mechanisms found in literature, only one was found to be in agreement with the measurements. (C) 2000 Else vier Science Ltd. All rights reserved.