Characteristics of Metal Cation Carbonation and Carbon Dioxide Utilization Using Seawater-Based Industrial Wastewater

In this study, carbon capture and utilization (CCU) technology was used to capture CO₂ in simulated industrial flue gas using industrial wastewater from a refined-salt production plant. Also, captured CO₂ was converted to metal carbonate salt which has a potential to be used as valuable product in another industry. In order to increase the purity of the products, the target ions were first separated from the industrial wastewater using pH control. And, three amine-type absorbents were used to transport CO₂ to the metal ions for carbonation reaction. However, for that which cannot make precipitated salt with ionic CO₂ species, direct carbonation method was applied. X-Ray Diffraction, Field-Emission Scanning Electron Microscopy, and Thermogravimetry/Derivative Thermogravimetry were used to investigate properties of the products. Mg and Ca product were comprised of nesquehonite- (purity: 95.150%) and calcite-dominant (purity: 96.51%) mixtures, respectively. Under the experimental conditions, the number of mole of CO₂ converted to valuable material in the total process was 0.9546 mol per 500 ml industrial wastewater.