New kinetic model for the rapid step of calcium oxide carbonation by carbon dioxide

• Published in: Journal of thermal analysis and calorimetry 2014-06, Vol.116 (3), p.1181-1188
• Main Authors: Rouchon, Lydie, Favergeon, Loïc, Pijolat, Michèle
• Format: Article
• Language: English
• Subjects: Analysis; Analytical Chemistry; Calcium carbonate; Calcium oxide; Carbon dioxide; Carbonation; Chemical and Process Engineering; Chemistry; Chemistry and Materials Science; Engineering Sciences; Inorganic Chemistry; Lime; Measurement Science and Instrumentation; Nucleation; Partial pressure; Physical Chemistry; Polymer Sciences; Reaction kinetics
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-013-3544-y

Carbonation of solid calcium oxide by gaseous carbon dioxide was monitored by thermogravimetry. A kinetic model of CaO carbonation is proposed in order to interpret the first rapid step of the reaction. By taking into account, the existence of large induction period as well as the sigmoidal shape of the kinetic curves in this kinetic-controlled region, a surface nucleation and isotropic growth kinetic model based on a single nucleus per particle is proposed, and the expressions of the fractional conversion and the reaction rate versus time are detailed. The induction period is found to have a linear variation with respect to temperature and to follow a power law with respect to CO 2 partial pressure. The areic reactivity of growth decreases with temperature increase, and increases with CO 2 partial pressure increase. A mechanism of CaCO 3 growth is proposed to account for these results and to determine a dependence of the areic reactivity of growth on the temperature and the CO 2 partial pressure.