(335aa) Reaction kinetics of magnesium-silicate based CO2 sorption

1School of Civil and Environmental Engineering, Georgia Institute of Technology,Atlanta, GA 30332, U.S.A, 2Department of Chemical and petroleum Engineering, University of Wyoming, Laramie, WY 82071,U.S.A., 3 Caterpillar's Product Development Center of Excellence, TC-E / 854, P.O. Box 1875, Peoria, Illinois 61656,U.S.A

Mineralization can be adopted as the potential CO2 sequestration process, which is the process of chemical weathering by alkaine-earth minerals to form stable carbonate minerals existed in a plenty of quantities in the Earth crust. The adsorptive performances of carbonation reaction of magnesium silicate (Mg2SiO4), which is a main constituent of the olivine, was carried out to estimate its potential application for the separation of CO2 in the presence of water vapor. The water vapor was found to play a significant catalytic role to improve the carbonation rate, and experimental results revealed that carbon dioxide can be bound into Mg2SiO4 minerals to form stable surface carbonates. Reaction activity of Mg2SiO4 was carried out by varying the temperature and residence time. Based on the changes of CO2 concentration with time during sorption, the reaction kinetic model of Mg2SiO4 carbonation reaction was developed. The reaction order was found to be approximately 1 for CO2. The activation energy derived for the Arrhenius equation of Mg2SiO4-based carbonation is 58.3 ± 5.8 kJ/mol based on the changes of reaction rates with temperature in the range of 100-200 oC. Consequently, this study will basically lay groundwork for the chemical mechanism of mineral carbonation with carbon dioxide in the presence of water vapor as well as provide relevant information for the practical application of CO2 sequestration by stable adsorption on mineral silicates.