Coupling Electrodialysis with Microbial Electrosynthesis Enables High rate, High titer, and Cost effective Acetate Production from CO2

Microbial electrosynthesis (MES) presents a promising strategy for the electrochemical conversion of CO2 into multicarbon compounds. However, its practical application is hindered by low production rates, low product titers, and high product costs. In this study, an electrolytic bubble column MES reactor was integrated with electrodialysis (ED) to enable simultaneous acetate production, extraction, and concentration. The in situ acetate extraction alleviated product inhibition markedly, resulting in an average acetate production rate of 4.32 g/L/d and a maximum acetate concentration of 98.1 g/L, exceeding most reported data by an order of magnitude. The reactor achieved a gas uptake efficiency of 100% during the stable operation phase and a coulombic efficiency of 83.6% in the whole operation process. Moreover, the system achieved a 98.7% reduction in NaOH consumption per unit of acetate compared to MES systems without electrodialysis. These results highlight the significant potential of the integrated electrodialysis and microbial electrosynthesis system for industrial-scale applications.