Simultaneous Sodium Hydroxide Production by Membrane Electrolysis and Carbon Dioxide Capture

The simultaneous process of NaOH production via electrolysis of NaCl and CO₂ capture was investigated due to the expectation of reduction in capital cost. It was found that seawater concentration of NaCl solution was adaptable to be used as both anolyte and catholyte and that 90 °C was the most proper temperature for NaOH production among the test conditions in this work. Under these electrolyte and temperature conditions, the simultaneous NaOH production and CO₂ capture processes were conducted and more than 98.83 % of OH⁻ was reacted with CO₂ to yield aqueous carbonate solutions. Additional electrochemical CO₂ capture tests were carried out depending on the different CO₂ concentration of mixed gases.