Process Design and Technoeconomic Analysis of Integrated Electrochemical CO ₂ Conversion to Ethanol

The pressing need to mitigate anthropogenic CO2 emissions from hard-to-abate sectors, such as cement manufacturing, has intensified the pursuit of carbon capture and utilization (CCU) technologies. This study addresses a critical gap in the system-level integration of CO2 capture, electrochemical conversion, and downstream product separation for ethanol production. An integrated process model was developed, coupling rate-based Aspen Plus simulations of postcombustion CO2 capture from cement flue gas with a custom Excel-based electrolyzer model employing Cu3Sn catalyst membrane electrode assemblies. Electrochemical conversion was simulated at a Faradaic efficiency of 64.3% for ethanol at an industrially relevant current density of 900 mA cm–2. Downstream separation, including extractive distillation, was used to achieve fuel-grade ethanol purity (≥99.5 wt %). Technoeconomic analysis revealed limited economic viability under baseline assumptions, with a net present value (NPV) of −2008 USD per tonne of CO2, driven primarily by high electricity demand (120 GJ per tonne ethanol). Sensitivity analyses demonstrated that reducing the cell voltage and securing electricity prices below 25 USD/MWh could shift the process into profitability under certain conditions. These findings highlight the necessity of co-optimizing capture, conversion, and separation technologies in tandem, and highlight the critical role of electrolyzer efficiency and electricity pricing in determining the commercial feasibility of CO2-to-ethanol pathways.