Kinetic Parameters of Biomass Pyrolysis – Comparison between Thermally Thick and Fine Particles of Biomass

In this study, kinetic parameters of fast and slow pyrolysis is compared. For fast pyrolysis, cylindrical wood pieces of 20 mm diameter and 50 mm length is pyrolysed in a tube furnace at temperatures ranging from 300°C to 500°C. Solid, liquid and gas products are collected and the yields are calculated. For slow pyrolysis, thermogravimetric analysis (TGA) is used using sawdust from the same biomass. Using the experimental data from two different methods the kinetic parameters are calculated such as activation energy and pre-exponential factor for the two different pyrolysis methods. For fast pyrolysis the parameters are found to be E = 32.5 kJ/mol and A = 35/min and for slow pyrolysis Es = 50.48 kJ/mol and As = 3179.86/min. The large difference between the values show that kinetic studies and modelling work using thermogravimetric analysis data is not suitable for commercial scale simulation. Also, the pre-exponential value for fast pyrolysis shows that the kinetic equation used from flash pyrolysis is not exactly suitable for this situation. Therefore, it is recommended that more studies on the kinetic parameters of fast pyrolysis of thermally thick biomass need to be done.