A sustainable bipolar membrane electrodialysis process for effective conversion of CO2 and NaCl brine into NaHCO3

Climate change demands innovative carbon capture and utilization (CCU) strategies, yet converting captured CO 2 into high-value products while managing industrial waste remains elusive. Here, we demonstrate a single-step, energy-efficient bipolar membrane electrodialysis (BMED) system integrated with CCU, enabling the simultaneous conversion of NaCl brine and CO 2 into high-purity sodium bicarbonate (NaHCO 3 ) with unprecedented efficiency, but without requiring external alkali sources or energy-intensive thermal regeneration steps. By optimizing key parameters – such as current density and CO 2 aeration rate, and gas–liquid flow ratios – we achieved a bicarbonate concentration of 1.186 mol/L in the alkaline chamber, coupled with 57.65% carbon sequestration efficiency and an energy consumption as low as 3.1 kW·h/m³ CO 2 (or 716.9 kW·h/t NaHCO 3 ). This approach not only recovers valuable sodium resources from brine but also enhances CO 2 absorption through electrochemical mechanisms, potentially reducing global carbon emissions by up to 20% in brine-intensive industries. Our work paves the way for scalable, sustainable CCUS technologies, transforming waste streams into economic assets and advancing the fight against climate change. Integration of BMED with CO 2 sequestration for NaHCO 3 production from NaCl brine. Energy-efficient and sustainable CO 2 utilization for marketable products. Optimization of key operational parameters for improved efficiency.