CO₂ Utilization through High Purity Metal Carbonate Production Based on Target Metal Separation

Abstract

This study deals with the Carbon Capture and Utilization (CCU) technology using alkanolamine absorbents solutions and pretreated brine solution which is produced as wastewater in refined salt production facility. Alkanolamine solutions were saturated by 15 vol% CO₂-N₂ mixed gas which assumed to be industrial flue gas emitted from normal coal-fired power plant. Unlike direct carbon fixation method, all of the experiments were performed under normal temperature range (298.15 - 343.15 K) and ambient pressure (101.325 Pa). Ca²⁺ ions contained in pretreated brine solution is used as metal ion supplying source. 30 wt% of aqueous monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA) solutions were used as absorbents, respectively, Also, calcium ions included in the wastewater was separated by using sodium sulfate producing calcium sulfate. After that, carbon dioxide was carbonated by the reaction between calcium sulfate. Though Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) analysis, precipitated salts were turned out to be calcite.