Char attrition is the main mechanism for the fine char generation in PFBC The char attrition rates were significantly different for each of the two coal chars tested. Specific char attrition rate increased with the surface porosity of burning char particles. A coal with higher ratio of telocollinite/inertinite contents formed chars in PFBC with larger pores or higher porosity during devolatilization, which resulted in a higher specific attrition rate.