Over the years, circulating fluidized bed systems have been designed for chemical conversion and energy recovery due to the ability of allowing continuous processing. While many CFB technologies are well established,a number of emerging technologies in recent years are utilizing the CFB concept, such as chemical looping combustion, novel continuous temperature swing adsorption, and transport gasifiers. A major uncertainty in these new technologies is the effect that attrition of bed material has On the overall process economics and system operability. This work presents a review of the study of attrition for CFB systems, including relevant material properties, basic modeling and prediction, as well as particle population balance techniques. Because some of these new processes use novel materials, this work focuses on applying fundamental material properties to the understanding of attrition. Published by Elsevier B.V.