Calcium looping is a developing CO2 capture technology. It is based on the reversible carbonation of CaOsorbent, which becomes less reactive upon cycling. One method of increasing the reactivity of unreactivesorbent is by hydration in the calcined (CaO) form. Here, sorbent has been subjected to repeated cycles ofcarbonation and calcination within a small fluidised bed reactor. Cycle numbers of 0 (i.e., one calcination),2, 6 and 13 have been studied to generate sorbents that have been deactivated to different extents.Subsequently, the sorbent generated was subjected to steam hydration tests within a thermogravimetricanalyser, using hydration temperatures of 473, 573 and 673 K. Sorbents that had been cycled less prior tohydration hydrated rapidly. However, the more cycled sorbents exhibited behaviour where the hydrationconversion tended towards an asymptotic value, which is likely to be associated with pore blockage. Thisasymptotic value tended to be lower at higher hydration temperatures; however, the maximum rate ofhydration was found to increase with increasing hydration temperature. A shrinking core model has beendeveloped and applied to the data. It fits data from experiments that did not exhibit extensive pore blockagewell, but fits data from experiments that exhibited pore blockage less well.
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