A multi-compartment electrochemical reactor, which simultaneously converts carbon dioxide (dissolved or gaseous CO₂) and high salinity waste-water to value-added chemicals, in the form of inorganic acids, carbonate salts and desalinated water, is demonstrated. The electrocehmical approach operates in electrodialysis or electrolytic mode and uses anion exchange and cation exchange membranes, and a Pt/Ir-coated Ti anode and Ti mesh cathode (for dissolved CO₂) or Pt/C-coated gas diffusion cathode electrodes (for gaseous CO₂) to produce acid and base products from CO₂ (or CO₂/O₂) and an aqueous NaCl feed. The electrodialysis mode operates with carbonic acid feed while the electrolytic approach electrochemically converts carbon dioxide from the gas phase. With the gaseous conversion of carbon dioxide, a non-selective catalyst (carbon-supported Pt) was used to reduce the oxygen into hydroxyl ions which further reacted with CO₂feed to form bicarbonate and carbonate species.

Under an applied voltage (~ 6 V) clear production of inorganic carbon salts and acids was observed. The product fluxes for HCl and NaHCO₃ were ~ 0.05 mM cm^-2 hr^-1 on average for the case of dissolved CO₂ and ~ 3.50 mM cm^-² hr^-1 for the case of gaseous CO₂ showing an enhancement factor of about 70x in the flux rates with the use of gaseous CO₂.

The bench-top (3.24 cm² electrodes) cell has been successfully scaled up (1,500x) to a 5,000 cm² NORASCAND^® commercial-scale electrolytic cell. Chemicals such as hydrochloric acid and bicarbonate salts have potential uses in many applications including oil and gas exploration and production where the chemicals as well as the desalinated water can be used in resource extraction. Coupling of CO₂ removal and water treatment as presented here has potential applications in both conventional and unconventional oil and gas operations. Evolution of the technology from the conceptual bench-top reactor to initial scale up efforts and the current status of technology will be presented during the meeting.