Attrition and microstructural characterization of limestones for fluidized bed combustion application

An experimental program was set up to assess the extent of fragmentation and attrition of two different limestones under simulated fluidized bed combustion conditions with sulfur capture. A combination of techniques based on bench-scale tests was used. In particular, a novel apparatus and procedure for the characterization of the fragmentation behavior under high velocity impact conditions was used. The sorbent samples were also characterized from the standpoint of their chemical and microstructural features, to correlate the attrition propensity with the sorbent texture. Differences between the attrition behavior of the two limestones are discussed in the light of a phenomenological model of sorbent particle sulfation/breakage.