Carbon Dioxide Capture Using an Electrochemically Driven Proton Concentration Process

Abstract

Summary: The 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.

Keywords

• CO2 capture
• electrochemical cell
• proton concentration process
• thermodynamic modeling
• MnO2 electrode