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

• Pilot-scale calcium looping process was demonstrated for post-combustion CO2 capture.
• Limestone and aluminate cement pellets were used as sorbents.
• The attrition of pellets is relatively insensitive to limestone type.
• 10% binder did not offer higher mechanical strength for pellets compared to limestone.
• The attrition of pellets is comparable to their parental limestone.

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 250–600 μm 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 250 μm. 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.

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