Carbonate Regeneration Using a Membrane Electrochemical Cell for Efficient CO₂ Capture

The use of atmospheric CO₂ as a chemical feedstock is a promising way to decarbonize the chemical and transportation sectors, which currently rely heavily on fossil fuels. This transition demands new technologies to reduce the energy required to capture and separate CO₂. Here, we develop and demonstrate an alternative method of carbonate solution regeneration using an anion exchange membrane electrochemical cell. This process simultaneously regenerates the CO₂ capture solution on the feed side, while enriching a stream of H₂ with CO₂ on the permeate side of the cell. Preliminary results show a CO₂ transport faradaic efficiency of 50% (100% CO₃ ^2- transport) when supplying a pure K₂CO₃ solution at current densities up to 60 mA·cm^-2. A small cathode gap benefited cell operation by preventing membrane transport of OH^-, although with an increased ohmic resistance. This represents a step forward in the application of electrochemistry to drive processes that are critical to CO₂ valorization.