Energy-efficient production of Ca(HCO2)2 via antisolvent crystallization and optimized amine-catalyzed CO2 hydrogenation: Combined techno-economic and environmental assessment

초록

The conversion of carbon dioxide (CO2) into value-added products such as calcium formate (Ca(HCO2)2) through carbon capture and utilization (CCU) technologies has emerged as a promising strategy for mitigating global warming. For industrial feasibility, both economic competitiveness and effective CO2 conversion must be achieved. To address the high energy consumption and cost associated with conventional Ca(HCO2)2 production, particularly in the energy-intensive evaporation step, an integrated CO2 hydrogenation process was developed. The implementation of antisolvent crystallization, an optimized amine separation system, and an enhanced catalytic strategy contributed to improved overall process efficiency. Through precipitation experiments and process modeling, the optimal acetone-to-water ratio was determined to be 1:1, which balances product yield and energy consumption. Techno-economic analysis (TEA) confirmed that this ratio provides the lowest production cost, while life-cycle assessment (LCA) revealed a trade-off between economic performance and environmental impact, with slightly lower CO2 emissions observed at a 0.75 ratio. Use of acetone as an antisolvent led to a 63% reduction in steam consumption compared to conventional water evaporation. Moreover, the complex distillation-based amine recovery process was replaced with a simplified phase separation method, improving operational simplicity. Catalytic system improvements further increased hydrogenation performance. TEA and LCA demonstrated a 24% reduction in production cost (518 USD/tCa(HCO2)2) and a 57% decrease in global warming potential (GWP, 1.72 kgCO2-eq/kgCa(HCO2)2) relative to traditional CO-based processes. These results highlight the environmental sustainability and economic viability of the proposed approach, indicating its potential for practical implementation in CCU applications.

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