The role of reaction temperature is investigated on the degradation dynamic
s of wood chips of different varieties, exposed to radiative heat fluxes in
the range 31-80 kW m(-2). Average heating rates vary from about 20 to 120
K min(-1), with steady temperatures between 600 and 900 K. At low temperatu
res, softwoods (redwood, fir, pine), on the one hand, and hardwoods (beech,
chestnut), on the other, present dynamics quantitatively similar, apart fr
om the lower devolatilization rate of chestnut with respect to beech wood.
On the whole, the softwood devolatilization rate is slower and attains its
maximum at longer times (higher temperatures). As the reaction temperature
is increased, it is essentially the ratio between the percentage of holocel
lulose and the other components in the wood chemical composition which main
ly determine the degradation characteristics. (C) 2001 Elsevier Science B.V
. All rights reserved.