Chemical kinetics of Japanese cedar, cypress, fir, and spruce and characterization of charcoal

Abstract

Thermogravimetric and differential thermal analyses techniques have been applied to investigate the thermal degradation characteristics and chemical kinetics of Japanese cedar, cypress, fir, and spruce. The decomposition of the components could be modeled by an Arrhenius kinetic expression. The kinetic parameters were extracted from the thermogravimetric data using least-squares techniques. The heating rates used for the analyses were 10°, 5°, and 0.33°C/min; and the activation energy and reaction order of the above woods were 7.54, 8.39, 2.87, and 7.88 kJ/mol and 0.71, 0.64, 0.44, and 0.63, respectively. Finally, carbonization was done to produce charcoal from these woods under various operating conditions, and the charcoal was characterized in respect to yield, heating value, electrical conductivity, and X-ray diffraction. The quality of the charcoal from fir was the best among the four types of wood. The charcoal produced is inferior to binchotan (white charcoal) in respect to electrical conductivity and crystalline structure.