Fouling management in oceanic carbon capture via in-situ electrochemical bipolar membrane electrodialysis

To assist reaching net-zero emissions, the dissolved carbon in ocean can be extracted to enable an indirect air capture. An electrochemical bipolar membrane electrodialysis (BPMED) is a sustainable method for such The BPMED enables pH-swing that manipulates oceanic carbonate-equilibrium using electricity. However, at alkaline-pH, in-situ process suffers from inorganic fouling within stack, increasing cost of In current work, we investigate management strategies including control (i.e., membrane- configuration and current-flow rate optimization) removal methods. Fouling methods CO2(g) sparging, CO2 (aq) cleaning, back-pressure, flow increase, acid-wash are investigated under accelerated conditions. stack containing BPM-AEM pairs shows 4 × lower than BPM-CEM while carbonate-extraction faradaic efficiency similar both configurations. From scaling methods, only acid wash combined with back-pressure removed all fouling, recovering cell voltage pressure drop their initial values. Upon total increased even more due trapped gas inside netted spacers. Cleaning via gaseous decreases pH, dissolving hydroxide/carbonate-based but carbonate-removal significantly which not preferred. Applying higher rates decelerated buildup was enough remove fouling. Using stacks combination periodic cleaning has potential as resilient BPMED.