Abstract: A dual-pathway system for CO2 capture in both acidified and basified streams is provided. The system may be embodied in an off-shore stand-alone facility to allow for the operation of oceanic CO2 capture to be more efficient and cost effective. Systems maintain high environmental standards by containing all intermediate acidic and alkaline solutions in a closed system so that the effluent discharged back into the ocean is at the similar pH and salinity as the feed oceanwater, with only CO2 removed. Acid and base produced by an electrodialyzer unit is used to achieve oceanwater decarbonization via gaseous CO2 removal and solid CaCO3 precipitates removal. The system is configured to require the processing of a very small fraction of the total oceanwater intake for the acid-base generation process.

Abstract: Systems and methods of gas-liquid contactors for direct ocean capture and/or direct air capture are described.

Abstract: Disclosed are electrochemical systems that include an electrodialyzer and a vapor-fed CO2 reduction (CO2R) cell to capture and convert CO2 from ocean water. The electrodialyzer includes a stack of bipolar membrane electrodialysis (BPMED) cells between end electrodes. The electrodialzyer incorporates monovalent cation exchange membranes (M-CEMs) that prevent the transfer of multivalent cations between adjacent cell compartments, allowing continuous recirculation of electrolytes and solutions, and thus providing a safer and more scaling-free electrodialysis system. In some embodiments, the electrodialyzer may be configured to replace the water-splitting reaction at end electrodes with one-electron, reversible redox couples in solution at the electrodes. As a result, in the entire electrodialyzer stack, there is no bond-making, bond-breaking reactions and there is no gas generation, which significantly simplifies the cell design and improves operational safety.