Attrition Characteristics of Limestone and Lime for in-Situ Desulfurization in a Circulating Fluidized Bed Combustor

In circulating fluidized bed combustors the particle size distribution of limestone might be important and should be managed to optimize in-situ desulfurization efficiency. In a attrition reactor for the American standard test method (ASTM) D5757-95, the attrition characteristics of various limestone and lime samples were investigated. 3 different limestones and limes generated in a fixed bed reactor operated at 700^oC were used to study attrition characteristics, such as particle size distribution, average particle size, attrition index and so on. The particle attrition of lime was more active than limestones which were generally used in circulating fluidized bed combustor. The attrition index of lime samples taken by ASTM D5757-95 was higher than those of limestone samples. The average particle sizes of limestone and lime samples decreased with increasing attrition. About 40-70 wt% samples of limestone and lime were entrained and lost.