Limestone particle attrition and size distribution in a bench scale bubbling fluidized bed

Attrition of limestone particles in bubbling fluidized bed has significant influence on cyclic CO₂ capture ability of sorbents. The limestone particle attrition and size distribution characteristics were investigated experimentally in a bench scale fluidized bed. The effects of initial particle sizes, fluidized velocity, attrition time and temperature on limestone attrition characteristics were studied. An empirical fitting correlation was proposed to describe the relationship of cumulative mass fraction of limestone fines (R) and attrition time (t). The results show that the fines generation rate decreases and particle size reduction rate increases with increasing initial size. Chipping of large particle takes predominant position when fluidized velocity exceeds the minimum fluidization velocity resulting in more prominent reduction of particle size. After 4 hours attrition, particle size reduction and fines generation rate become constant. It is suggested that cumulative mass fraction of limestone fines (R) increases with attrition time with a function of decaying exponential correlation.