Simulation and optimization of CO2 mineralization for sustainable cement production

Abstract

The cement industry is responsible for a significant portion of global CO₂ emissions, primarily due to the calcination of limestone and the combustion of fossil fuels—both of which result in unavoidable process-related emissionsGiven the scale and persistence of these emissions, conventional mitigation strategies are insufficient, underscoring the urgent need for advanced technologies such as carbon capture, utilization, and storage (CCUS). Among CCUS pathways, CO₂ mineralization offers a promising solution by converting carbon dioxide into stable mineral carbonates useable in construction materials. Furthermore, integrating alternative solid fuels and plastic waste in cement production, along with utilizing cement by-products as CO₂ absorbents, has gained increasing interest. This study simulates a CO₂ mineralization unit within a plug-flow reactor. The system is further extended to separate unreacted materials and products for potential reuse. Key operating parameters—pressure, temperature, molar ratios, and residence time—were systematically optimized. At 1 bar, 303 K, molar ratios of CO₂, KOH, and N₂ to CaCl₂ of 2.06, 4.05, and 7.08, respectively, and a residence time of 45.0 s, a CO₂ conversion of 98.3 % was achieved. The results demonstrate the potential of the proposed approach to significantly reduce the carbon footprint of cement manufacturing through effective CO₂ utilization. Furthermore, three different cases were evaluated through a comprehensive techno-economic analysis: Case 1 involved CO₂ sourced from SRF (Solid Recovered Fuel) with natural gas as the energy input; Case 2 considered CO₂ captured from a cement plant using natural gas; and Case 3 combined CO₂ from a cement plant with SRF as the energy source.