Characterization of char and soot from millimetric wood particles pyrolysis in a drop tube reactor between 800 °C and 1400 °C

• Char and soot from wood particles pyrolysis in a DTR were characterized.
• Char and soot characteristics change with temperature and residence time.
• Gasification kinetic parameters of char and soot from wood pyrolysis were determined.
• Gasification experiments in TGA were modeled using a semi-empirical approach.
• Conversion times in industrial conditions were estimated by model extrapolation.

Char and soot characterization was performed for samples obtained from beech particles pyrolysis in a drop tube reactor at various temperatures and residence times. Firstly, an experimental study was performed and highlights the variation of char and soot composition and reactivity with operating conditions. A structure ordering with temperature for soot samples was also experimentally put into evidence. These variations are believed to be consequence of structural changes during char thermal annealing and soot formation process, affecting both carbonaceous matrix and mineral matter. Secondly, a semi-empirical model was developed and validated with thermogravimetry experiments. This model was then used for conversion time estimation in conditions representative of an entrained flow reactor, and shows that a complete conversion of char and soot is possible in a few seconds under severe operating conditions.