Carbon Dioxide Capture Using an Electrochemically Driven Proton Concentration Process

he development of sustainable CO₂ capture technologies is critical to address issues associated with global warming. In this context, the concept of an electrochemically driven proton concentration process is developed for the capture of CO₂ based on modulation of the proton concentration in an electrochemical cell by a proton intercalating MnO₂ electrode. The pH sensitivity of CO₂ hydration is leveraged such that CO₂ is absorbed as bicarbonate and carbonate ions at high pH values and desorbed as gas at low pH values. The electrochemical work requirement for the proposed proton concentration process to desorb CO₂ captured from a flue gas stream is estimated to be 33.2 kJe/mol CO₂, suggesting that this process is competitive with other similar electrochemical-based approaches. The experimental results show that the generated current in a symmetrical electrochemical cell with fabricated electrodes is effectively translated into proton intercalation/deintercalation reactions through reversible cycles, resulting in modulated proton concentrations.