An internally circulating fluid bed for attrition testing of Ca looping sorbents

Particle breakage, i.e. attrition, inevitably occurs in most processes involving the transport of solid particles, such as Ca looping processes. Attrition can have nefarious effects on the operation of such systems as it affects the hydrodynamics of the system and increases the need for gas clean-up. Therefore characterizing the particles' tendency to break, i.e. their friability, is essential for the design and development of Ca looping processes. Although a number of friability testing methods exist and have been used to produce satisfying results, it is argued here that existing methods cannot easily provide a full characterization of the friability of Ca looping sorbents. A new friability testing method is proposed in this work to overcome this difficulty, based on the use of an internally circulating fluid bed (ICFB). A prototype apparatus was built and the feasibility of this method evaluated.