Reduced reagent regeneration energy for CO2 capture with bipolar membrane electrodialysis

Post combustion CO2 capture with reagents such as amines, sodium carbonate and sodium hydroxide is the most mature CO2 capture technology. One of the major challenges facing post combustion CO2 capture is the high energy requirement for reagent regeneration. Thermal regeneration energy is in the range of 3-4 MJ/Kg CO2 captured. We were able to achieve reagent regeneration energy as low as 1.18 MJ/Kg CO2 with the help of electrodialysis with bipolar membrane separation (EDBM). This value is significantly lower compared to thermal regeneration. Also, switching from toxic reagents like amines to alkali absorbents like sodium carbonate and sodium hydroxide will save reagent costs. This technology will be particularly attractive in the future as membrane prices go down. These traits not only make this technology economically feasible, but also environmentally benign.