Evolution of sorptive and textural properties of CaO-based sorbents during repetitive sorption/regeneration cycles: Part II. Modeling of sorbent sintering during initial cycles

A new model describing the evolution of sorptive and textural properties of a CaO-based sorbent during repetitive sorption/regeneration cycles has been developed. The proposed model considers the morphology of nascent monodisperse CaO and the sintering of sorbent grains upon the assumption of the surface mass-transfer mechanism. In addition, the obtained model allows predicting the change in the textural properties of the sorbent (e.g. the values of specific surface area and mean pore size) during the sorption/regeneration cycles. The obtained results show that the model of surface sintering is well applicable to the description of the decay of the sorbent sorption capacity in initial several cycles, while the previously developed model of the volume sintering provides good prediction of this decay only after several cycles. It can be assumed that during the cycling, the sintering of the sorbent switches from the surface to the volume regime.