The large-scale storage of biomass pellets is challenging due to health issues, material loss, and the risk of fire and explosions. The thermal conductivity is a material property which plays a key role in determining the self-heating properties of biomass. Meanwhile, understanding the thermal conductivity and the affecting factors help to better understand and reduce the risk of self-heating and fire explosions. This poster investigates the effect of particle size distribution and bulk density on the thermal conductivity of biomass pellets.