A Modified Random Pore Model for Carbonation Reaction of CaO-based Limestone with CO₂ in Different Calcination-carbonation Cycles

In this work, a modified model was presented. The simulation results showed that the modified model was capable to predict the whole conversion-time curve of the carbonation reaction in long series of calcination-carbonation cycles, particularly at short reaction times, including the sudden transition between the first fast regime and the second product layer diffusion controlled slow regime. In comparison with the model of Grasa, to determine the value of conversion corresponding to the transition between regimes (X_k-D) was unnecessary in the modified model. In addition, compared with the models of Sun and Benedett, the modified model proposed here was capable of predicting with a reasonably good accuracy the carbonation rates obtained in the relevant range of reaction times and conditions in long series of calcination- carbonation cycles, and concept to be successfully applied.