Carbon Dioxide Sequestration by Mineral Carbonation Using Alkaline Rich Material

Abstract

Mineral carbonation is the carbonation of alkaline silicate Ca/Mg minerals, which is replica of the regular weathering processes. Mineral carbonation comprises of the reaction between the minerals and carbon dioxide to form a safe and stable mineral carbonate product. The present investigations deal with the usage of industrial alkaline rich waste (IAW) containing considerable amount of metal oxides as the possible raw material for the carbonation process. The suitability of applying the aqueous scheme of mineral carbonation by using steel slag is studied. The material is economical and is available easily near the large point sources of carbon dioxide emissions, and due to the chemical instability tend to react with carbon dioxide. Various process variables were considered to check the extent of carbonation like the temperature, pressure, liquid to solid ratio, reaction time. Chemical analysis was conducted to check the extent of carbonation. The experiments were carried out in artificial carbonation reactor. The particle size of the samples considered was less than 90 microns and distilled water was used as the medium to carry out carbonation. A maximum of 44% of carbonation was achieved for steel slag at a temperature of 100 ˚C, carbon dioxide pressure of 10 Kg/cm2, liquid to solid ratio of 6 and reaction time of 2 hours.