Attrition of sorbents during fluidized bed calcination and sulphation

The attrition behavior of two different limestones during calcination and s ulphation in fluidized beds has been investigated by a combination of exper imental techniques. The aim of the study is to shed light on the interactio ns between sorbent attrition and the change of particle mechanical and morp hological properties associated with the progress of chemical reactions. A number of different experimental techniques have been used to characterize breakage mechanisms relevant to particle attrition in different sections of industrial fluidized bed reactors operated at atmospheric pressure. Primar y fragmentation and abrasive attrition were characterized in situ by means of experiments carried out in a bench-scale fluidized bed reactor operated batchwise. Fragmentation under high velocity impact conditions was studied ex situ by means of single particle impact tests on pre-conditioned samples at room temperature. Scanning electron and optical microscopy analyses of the particles and EDX mapping of polished particle cross-sections were used to relate topography and internal composition of sorbent particles to the attrition mechanism. (C) 2000 Elsevier Science S.A. All rights reserved.