Attrition of CaO-based pellets in a 0.1 MWth dual fluidized bed pilot plant for post-combustion CO2 capture

Abstract

This work investigates the attrition of CaO-based pellets in pilot-scale calcium looping cycles for post-combustion CO2 capture. Two groups of pellets with size 250–600μm were prepared from Canadian and Spanish limestones using 10% calcium aluminate cement as a binder. The results showed that all groups of pellets experienced a significant extent of attrition as ~50% of the sorbent fed to the system was collected as fragments with particle size smaller than 250μm. The attrition of pellets was found to be comparable to that of limestone tested under similar conditions. The results also indicated the same tendency of attrition for all groups of pellets, with attrition extent being relatively insensitive to limestone type used for pelletization or injection method of sorbent to the system. The attrition trends suggest that the improvement in the mechanical strength of the pellets was marginal compared to that of limestone.