Biomass fast pyrolysis in a drop tube reactor for bio oil production: Experiments and modeling

Chamseddine Guizani (1) , Sylvie Valin (1) , Joseph Billaud (1) , Marine Peyrot (1) , Sylvain Salvador (2)

1 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
2 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement

Woody biomass fast pyrolysis in Entrained Flow Reactor (EFR) is studied both with experiments in a lab-scale drop tube reactor (DTR) and simulations with a 1-D model. The parameters of the study are temperature (450-600 degrees C), woody biomass particle size (370-640 mu m) and gas residence time (12.6-20.6 s). The most critical phenomena affecting the bio-oil yield are considered in the model: heating of the biomass particles, slip velocity of the biomass particles varying with biomass/char properties, biomass pyrolysis and tar cracking. The analyses of all products - char, bio-oil and gas - also brought information on the advancement of the pyrolysis and cracking for the different tests. The reactor temperature and particle size were found to have a major influence on the pyrolysis product distribution. The production of bio-oil reaches a maximum of 62.4 wt.% at 500 degrees C for the 370 mm particles. The particle conversion advancement is then estimated at 94% at the reactor exit. The bio-oil yield is lower at higher temperatures for a constant particle size due to tar cracking. At 550 degrees C, increasing the particle size from 370 mm to 640 mu m induces a decrease of the bio-oil yield from 48.3 to 34.8 wt.%, which was shown to be due to incomplete pyrolysis of the particles, because of a too short residence time as well as a too long heating time of particles. The pyrolysis conditions - temperature, particle size - were not found to have any significant influence on the bio-oil properties, such as acidity.

Mots clés: Modeling; Biomass; Fast-pyrolysis; Drop tube reactor; Experiments

Domaines: Génie des procédés

Chamseddine Guizani, Sylvie Valin, Joseph Billaud, Marine Peyrot, Sylvain Salvador. Biomass fast pyrolysis in a drop tube reactor for bio oil production: Experiments and modeling. Fuel, 2017, 207, pp.71-84. ⟨10.1016/j.fuel.2017.06.068⟩. ⟨hal-01581812⟩