Oxidative pyrolysis of pine wood, wheat straw and miscanthus pellets in a fixed bed

Xuan-Huynh Pham (1, 2) , Bruno Piriou (2) , Sylvain Salvador (3) , Jeremy Valette (2) , Laurent van de Steene (1, 2)

1 HUST - Hanoi University of Science and Technology
2 UPR BioWooEB - BioWooEB
3 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement

Oxidative pyrolysis is a key step in the autothermal operation of many fixed-bed reactors for staged gasification and advanced carbonisation. In these reactors, biomass is converted into charcoal, condensates and permanent gases inside a moving Oxidation Zone (OZ) which also produces energy to self-sustain the process. Oxidative pyrolysis of three different biomass types: pine wood, miscanthus and wheat straw pellets, was performed in a batch 20 cm diameter fixed bed reactor. Results showed that the OZ consumed 11% to 14% of the stoichiometric air to self-sustain the process and reached a peak temperature around 720 °C whatever the biomass. The propagation velocity and thickness of the OZ were inversely proportional to the ash content and to the bulk density of the biomass. Ash was also shown to influence the yield and composition of the resulting products due to a catalytic effect on primary and secondary pyrolysis reactions.

Mots clés: Oxidative pyrolysis; Oxidation zone; Fixed bed; Biomass; Smouldering

Domaines: Sciences de l'ingénieur [physics]

Xuan-Huynh Pham, Bruno Piriou, Sylvain Salvador, Jeremy Valette, Laurent van de Steene. Oxidative pyrolysis of pine wood, wheat straw and miscanthus pellets in a fixed bed. Fuel Processing Technology, 2018, 178, p.226-235. ⟨10.1016/j.fuproc.2018.05.029⟩. ⟨hal-01806681⟩