Rufer et al. (2025): Carbonate/Hydroxide Separation Boosts CO₂ Absorption Rate and Electrochemical Release Efficiency
Simon Rufer, Tal Joseph, Zara Aamer, Kripa K. Varanasi, IN: ACS Energy Letters, https://doi.org/10.1021/acsenergylett.5c00893
Electrochemical CO₂ capture systems using hydroxide solutions face stiff performance trade-offs, as the hydroxide ions necessary for rapid CO₂ absorption reduce the current efficiency of subsequent electrochemical CO₂ release. In this work, the authors propose a carbonate/hydroxide separation step between CO₂ absorption and release to provide a concentrated carbonate stream for efficient electrochemical release and a separate hydroxide stream for rapid absorption. They combine experiments on CO₂ absorption, nanofiltration separation, and electrochemical release to build a comprehensive model that illustrates system performance trade-offs.