Development of an Electrochemical Acidification Cell for the Recovery of CO2 and H2 from Seawater

Based on continuous electrodeionization (CEDI) technology, a novel hybrid electrochemical acidification process has been developed to extract large quantities of CO2 from seawater. This indirect approach acidifies seawater to recover CO2 from bicarbonate. The electrolytic regeneration of cation exchange resin allowed simultaneous and continuous ion exchange and regeneration to occur within the cell along with control of the seawater pH. Lowering seawater pH was found to be proportional to the applied current to the cell, and the CO2 in the acidified seawater was readily removed at pH less than 6.0. In addition, the cell produced a portion of hydrogen gas without additional energy penalties.