This study focuses on the energy potential and combustion process of torrefied wood. Samples were prepared through the torrefaction of five types of wood: Ash, beech, oak, pine and spruce. These were heated for 2 h at a temperature of 300 °C under a nitrogen atmosphere. Torrefied wood was prepared from wood samples with dimensions of 100 × 100 × 20 mm3. These dimensions have enabled investigation of torrefied wood combustion in compact form. The effect of the external heat flux on the combustion of the samples was measured using a cone calorimeter. The observed parameters, include initiation times, heat release rate and combustion efficiency. The results show that increasing the external heat flux decreases the evenness of combustion of torrefied wood. At the same time, it increases the combustion efficiency, which reached an average value of approximately 72% at 20 kW m-2, 81% at 30 kW m-2 and 90% at 40 kW m-2. The calculated values of critical heat flux of the individual samples ranged from 4.67 kW m-2 to 15.2 kW m-2, the thermal response parameter ranged from 134 kW s0.5 m-2 to 297 kW s0.5 m-2 and calculated ignition temperature ranged from 277 °C to 452 °C. Obtained results are useful both for energy production field and for fire safety risk assessment of stored torrefied wood.
Keywords: combustion; fuel; heat release rate; torrefied wood.