Integrated Bipolar Membrane Electrodialysis and Electrolysis for CO ₂ Capture and Conversion

ABSTRACT Decarbonization of seawater using carbon capture and conversion technologies remains a significant process engineering challenge. Here, we present an integrated system for combined CO ₂ capture and conversion, which couples bipolar membrane electrodialysis (BMED) with a CO ₂ electrolyzer (CO ₂ E) in a single system (BMEED). Electrochemical extraction and conversion of dissolved inorganic carbon (bicarbonate) are demonstrated using concentrations ranging from seawater level (0.0025 M) to carbon capture absorbents (0.5M), achieving a specific energy consumption of 3.90 kWh/kg‐. Integrated BMEED achieved a to CO conversion selectivity of 98% and a specific energy consumption of 34.00 kWh/kg‐CO. By comparison, two independent subsystems exhibit 98% selectivity and 39.22 kWh/kg‐CO, which is 17% higher. Techno‐economic analyses reveal BMEED reduced the levelized cost of CO production by 42% compared to the stand‐alone carbon capture and conversion subsystems. Integration shifts CO production from a non‐profitable baseline to a profitable scenario of $193/ton‐CO. BMEED demonstrates the advantages of process intensification for CO ₂ capture and conversion and establishes a promising, energy‐efficient electrochemical pathway.