Conversion of saline water and dissolved carbon dioxide into value-added chemicals by electrodialysis

We demonstrate a new approach that simultaneously converts dissolved carbon dioxide and high salinity waste-water to desalinated water and value-added chemicals in the form of inorganic acids and carbonate salts. A four compartment electrodialysis cell module using anion exchange and cation exchange membranes, and a Pt/Jr-coated Ti anode and Ti mesh cathode was used to produce HCI and NaHCO3 products from CO2 and NaCI feed. Cell operation consisted of feeding the cell with carbonic acid (CO2 dissolved in water) and a saline solution of sodium chloride. Under an applied voltage clear production of inorganic carbon salts and acids was demonstrated. The product fluxes for HCI and NaHCO3 were similar to 0.05 mM cm(-2) h(-1) on average. A mathematical model for this electrodialysis cell configuration was developed to better understand limitations within the cell which are not available from experimental data including concentration profiles within the intra-membrane channels. (C) 2017 Elsevier Ltd. All rights reserved.