Heat transfer characteristic of wheat straw particle during the pyrolysis

The internal heat transfer within wheat straw particles is essential to the pyrolysis yield and energy consumption of wheat straw. To investigate this pyrolytic property, the paper first investigates the shape of particles after crushing and show a very pronounced platy structure, especially in the particle size range of 3 - 20 mm. Therefore, a thin rectangular model is more appropriate to describe the particle. On this basis, a mathematical model of heat transfer during pyrolysis of particle is developed and the thermal behavior of the interior of particles is analyzed with the heat of pyrolysis as a heat sink for the interior. The results of the calculations show the importance of platy structural features for heat transfer processes as well as for particle fragmentation. Finally, the residence time of the wheat straw in the pyrolysis reactor is slightly greater than the heating time of the wheat straw particle.