Research Progress on CO₂ Capture Materials and Mineral Carbonation Technologies from Coal Gasification Slag

Abstract

Coal gasification slag (CGS), an important by-product of the coal chemical industry, is rich in elements such as silicon, carbon, calcium and magnesium with a unique mineral composition, and has become an important raw material for CO₂ capture and mineralization. Utilization of CGS as a precursor for CO₂ capture material synthesis and CO₂ mineralization can significantly reduce the costs of traditional technologies, achieve the high-value utilization of CGS, and promote the synergistic reduction of pollution and CO₂ emissions in the coal chemical industry. Herein, a comprehensive review on the research progress regarding CO₂ capture and mineralization using CGS was provided. The synthetic strategies and mechanisms of silicon-based, carbon-based, and carbon-ash composite adsorbents derived from CGS for CO₂ capture were presented in detail, while the effects of different treatments on the structural properties and CO₂ capture capacity of adsorbents were summarized and compared. In addition, the mechanisms and the research progress on different technologies using CGS for CO₂ mineral carbonation were introduced. Finally, the problems existing in the application research of CGS in CO₂ capture and mineralization were discussed. It was recommended that more in-depth studies should be conducted focusing on performance enhancement, preparation process optimization, coupling technology development for the preparation of CO₂ capture materials and mineralization from CGS, as well as economic feasibility evaluations.