The different modes and sources of attrition relevant to fluidized bed combustion and gasification are surveyed. The broad spectrum of attrition mechanisms and phenomenologies is comprehensively described. The survey addresses attrition of the different types of solids employed in fluidized bed combustion and gasification: solid fuels, sorbent materials, inert bed solids (ash and ballast materials, e.g. sand). Moreover, the survey considers attrition of bed solids that are currently employed in modern solids looping processes aimed at CCS-ready conversion of solid fuels, e.g. sorbents in carbonate looping and oxygen carriers in chemical looping combustion and gasification. The analysis specifically addresses the important topic of the mutual interaction between attrition and the progress of chemical reactions. The current status of modeling of attrition phenomena and the available tools to account for attrition in comprehensive population balance models of fluidized bed combustors and gasifiers are presented. © 2013 Woodhead Publishing Limited. All rights reserved.