Weight loss dynamics of wood chips under fast radiative heating

The role of reaction temperature is investigated on the degradation dynamics of wood chips of different varieties, exposed to radiative heat fluxes in the range 31-80 kW m2. Average heating rates vary from about 20 to 120 K min1, with steady temperatures between 600 and 900 K. At low temperatures, softwoods (redwood, fir, pine), on the one hand, and hardwoods (beech, chestnut), on the other, present dynamics quantitatively similar, apart from 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 holocellulose and the other components in the wood chemical composition which mainly determine the degradation characteristics.