Abstract
Biocarbon, produced from renewable biomass, possesses unique physical and chemical properties that allow
its utilization in metal production to replace conventional reductants, thereby reducing the carbon footprint and
enhancing sustainability in metallurgical industries. However, there are risk related self-ignition and firing of
biocarbon with toxic emissions along values chains from production to end users. This study investigates the
combustion characteristics of wood biocarbon using a cone calorimetry. During cone calorimetry tests, the heat
release rate (HRR), peak HRR, total heat release (THR), mass loss, and CO and CO₂ release profiles were
monitored for two particle size ranges: 0.5 ≤ d ≤ 1 mm and 4 ≤ d ≤ 6.3 µm. Significantly different results were
observed based on particle size, demonstrating distinct flammability and combustibility behaviour. The smaller
particle size yielded a higher THR 55.8 MJ/m², compared to the larger size (40.8 MJ/m²). Conversely, the smaller
particles resulted in a lower peak HRR (28.7 kW/m²) than the larger particles (30.2 kW/m²). These differences
are attributed to variations in bulk density and surface area within the sample holder. The higher bulk density of
the smaller particles limits heat transfer but increases the total sample mass, thus increasing the THR. In both
particle sizes, an ash layer formed on the surface, which likely hindered heat and mass transfer during the
conversion of the underlying carbon material. These findings provide valuable data for assessing the ignition,
combustion, and flammability properties of biocarbon. Results from the current study are valuable for assessing
properties of biocarbon related to ignition, combustion and flammability