Parametric Study of the CaO−Ca12Al14O33 Synthesis with Respect to High CO2 Sorption Capacity and Stability on Multicycle Operation

This study focuses on the effect of various parameters of the synthesis procedure of the CO2 sorbent—CaO−Ca12Al14O33 derived from calcium acetate—on the CO2 sorption ability and lifetime. The synthesis procedure consists of the calcination of the acetate CaO precursor (step 1), the precipitation of the CaO with aluminum nitrates (step 2), followed by calcination at 500 °C for nitrates removal (step 3) and the calcination at 900 °C for the synthesis of Ca12Al14O33 (step 4). It has been shown, by employing TGA, that the applied difference in the calcination conditions (900 °C/2 h, 850 °C/1 h, 750 °C/0.5 h,) for the decomposition of the CaO acetate precursor (step 1) is not adequate to affect the sorption fixation and stability results. On the other hand calcination history of the precipitate and the addition of water in between the two calcination steps (nitrates removal and Ca12Al14O33 synthesis reaction) are of high importance for ensuring sorption capacities higher than 6.5 mol CO2/kg of sorbent in the f...