Comminution of carbon particles in a fluidized bed reactor: A review

•Comminution impact on fluidized bed combustion of carbon fuels have been reviewed.•Factors that affect comminution in fluidized bed reactor have been discussed.•Fines generation and their afterburning increase coarse char combustion rate.•Carbon loss via elutriation is crucial in low reactive fuels.•Initial particle size and distribution change depending on fuel type.