Table 1 Temperature ranges of wood pyrolysis and combustion

>100°C

The evaporation of chemically unbound water.

160-200°C

The three polymeric components of wood begin to decompose slowly. Gases formed at this stage are non-combustible (mainly H₂O).

200-225°C

Wood pyrolysis is still very slow, and most of the gases produced are non-combustible.

225-275°C

The main pyrolysis begins and flaming combustion will occur with the aid of a pilot flame.

280-500°C

Gases produced are now volatile (CO, methane etc.) and smoke particles are visible. Char forms rapidly as the physical structure of wood breaks down.

>500°C

Volatile production is complete. Char continues to smoulder and oxidise to form CO, CO₂ and H₂O.