Mineral carbonation of red gypsum for carbon dioxide sequestration

Abstract

Reduction of carbon dioxide (CO2) emissions into the atmosphere is a key challenge in order to mitigate the anthropogenic greenhouse effect. A CO2 emission causes lots of problems to human health and increases the global warming, CO2-uptake decreases these environmental issues. Mineral carbonation process is an alternative method during which industrial wastes rich in calcium (Ca) or magnesium (Mg) react with CO2 to form a stable carbonated mineral. In this research the feasibility of CO2 mineral carbonation by the use of red gypsum, as a Ca-rich source, was technically evaluated using autoclave mini reactor. For this purpose, the effect of a wide-range of key procedure variables such as reaction temperature, reaction time, particle size, stirring rate, CO2 pressure, and liquid to solid ratio, on the rate of mineral carbonation were studied. The results show that the maximum conversion of Ca (98.8%) is obtained at the condition that has optimum amount of these variables. Moreover, the results confirmed that red gypsum has high potential to form calcium carbonate (CaCO3) during the process of CO2 mineral carbonation. It was concluded that mineral carbonation process using red gypsum could be considered as an attractive and lowcost method in industry to mitigate considerable amount of CO2 from the atmosphere, which is the main issue in the current and coming years.