Reaction Kinetics of CO₂ Carbonation with Mg-Rich Minerals

Abstract

Due to their low price, wide availability, and stability of the resulting carbonates, Mg-rich minerals are promising materials for carbonating CO(2). Direct carbonation of CO(2) with Mg-rich minerals reported in this research for the first time could be considerably superior to conventional liquid extraction processes from an energy consumption perspective due to its avoidance of the use of a large amount of water with high specific heat capacity and latent heat of vaporization. Kinetic models of the reactions of the direct CO(2) carbonation with Mg-rich minerals and within simulated flue gas environments are important to the scale-up of reactor designs. Unfortunately, such models have not been made available thus far. This research was initiated to fill that gap. Magnesium silicate (Mg(2)SiO(4)), a representative compound in Mg-rich minerals, was used to study CO(2) carbonation reaction kinetics under given simulated flue gas conditions. It was found that the chosen sorbent deactivation model fits well the experimental data collected under given conditions. A reaction order of 1 with respect to CO(2) is obtained from experimental data. The Arrhenius form of CO(2) carbonation with Mg(2)SiO(4) is established based on changes in the rate constants of the chosen deactivation model as a function of temperature.