Feasibility of CO2 desorption and electrolytic regeneration of potassium carbonate solution in an anion exchange membrane cell

Abstract

In this work, an electrolytic process was introduced for coupled regeneration of potassium carbonate (K2CO3) solution and water electrolysis by using an anion exchange membrane cell. The process made the CO2 separation from O2 much easier with respect to the existing cationic exchange membrane process. The solution of K2CO3 was used in the cathode chamber to simulate the solution after absorbing CO2. The solution of sulfuric acid (0.1 mol/L H2SO4) was charged in the anode chamber. The feasibility of the process was discussed. The effects of various operation parameters, including temperature, current density, and electrolysis time, were studied. The results indicate that both the yield rate of CO2 and the current efficiency increase initially and decrease afterward with temperature. The yield rate of CO2 increases while the current efficiency decreases with the current density. A low current density can reduce the energy consumption for producing the same amount of CO2. The processes using anion exchange membrane electrolysis can regenerate the absorbent solution to achieve 89% current efficiency, and the simultaneous production of three pure gases, CO2, H2, and O2, makes this method promising.