Char-formation kinetics in the pyrolysis of sawdust in a conical spouted bed reactor

Both the generation of a microporous structure and char formation kinetics have been studied in the pyrolysis of sawdust of Pinus insignis in a conica l spouted bed reactor, in the range 350-700 degrees C. The BET surface area (representative of the physical evolution of the solid) and the C/H ratio of the solid (representative of the chemical structural change) have been t aken as conversion indices. From the measurement of the C/H ratio of the so lid (the more significant variable), it has been determined that the reacti on order is 0.5 and that the kinetic constant is between 0.18 min(-1) at 35 0 degrees C and 1.26 min(-1) at 700 degrees C. However the value of the con stant is almost independent of temperature, at 1 min(-1) in the range 500-7 00 degrees C. (C) 2000 Society of Chemical Industry.