Mathematical modelling of slow pyrolysis of a particle of treated wood waste.
Low-temperature pyrolysis is a possible method for the disposal of wood waste treated with chromated copper arsenic (CCA). A mathematical model (heat and mass transfer) including chemical reactions of the thermal degradation of a particle of wood is presented. A spherical particle is heated by a convective nitrogen flow. The progress of the pyrolysis process is characterized by three main steps: (1) drying of the wet sample; (2) heating of the sample until ignition of pyrolysis reactions; (3) pyrolysis and subsequent production of char and volatiles. The mathematical model is based on the volume averaging concept and it uses Shafizadeh and Chin [F. Shafizadeh, P.S. Chin, Thermal deterioration of wood, wood technology: chemical aspects, ACS Symposium Series 43 (1977) 57-81] pyrolysis model to describe the reaction pathway. It is solved by the line method, taking time as the preferred variable. Our model predicts intra-particle profiles for several variables (temperature, moisture content, concentration of wood). Simulations are presented with a spherical particle of 1cm radius.
Ratte
J
J
Thermya, 1 Rue Nicolas Appert, Villenave D'Ornon, France.
Marias
F
F
Vaxelaire
J
J
Bernada
P
P
D000465:Algorithms; D001152:Arsenicals / Q000737:chemistry; D002857:Chromium / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D003890:Desiccation; D004058:Diffusion; D004735:Energy Transfer; D017745:Incineration / Q000706:statistics & numerical data*; D007220:Industrial Waste / Q000032:analysis*; D007700:Kinetics; D015233:Models, Statistical; D015203:Reproducibility of Results; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry; D014934:Wood
D001152:Arsenicals; D007220:Industrial Waste; D014867:Water; D002857:Chromium; D003300:Copper