Safe storage of selected fuels with regard to their tendency to spontaneous combustion

•Fossil fuels and solid biofuels have tendency to spontaneous combustion.•We used methods based on Frank-Kamentskii theory of thermal explosion.•Five samples of coal and biomass were evaluated by oven test according to EN 15188.•Results were evaluated and extrapolated in two different ways depending on the type of fuel.•Storage of wood materials is safer than coal storage.

European standard EN 15188 is dedicated to the assessment of the tendency of solid flammable substances to spontaneous combustion. Fossil fuels and biofuels that substitute them are a frequent reason of fires caused by spontaneous combustion. Even though having different properties, both types of fuels can be assessed according to this standard by the method of the determination of the dependency of self-ignition temperature against the ratio of volume to surface area of geometrically exactly defined solid body, or based on the theory of thermal explosion according to Frank-Kamenetskii. The comparison of calculated values confirmed the agreement of both methods results, and the tendency of fuels to spontaneous combustion can be assessed by them.