Direct Air Capture Using Electrochemically Regenerated Anion Exchange Resins.

Direct air capture (DAC) aims to remove CO directly from the atmosphere. In this study, we have demonstrated proof-of-concept of a DAC process combining CO adsorption in a packed bed of amine-functionalized anion exchange resins (AERs) with a pH swing regeneration using an electrochemical cell (EC). The resin bed was regenerated using the alkaline solution produced in the cathodic compartment of the EC, while high purity CO (>95%) was desorbed in the acidifying compartment.

Electrochemical Regeneration of Spent Alkaline Absorbent from Direct Air Capture.

CO capture from the atmosphere (or direct air capture) is widely recognized as a promising solution to reach negative emissions, and technologies using alkaline solutions as absorbent have already been demonstrated on a full scale. In the conventional temperature swing process, the subsequent regeneration of the alkaline solution is highly energy-demanding. In this study, we experimentally demonstrate simultaneous solvent regeneration and CO desorption in a continuous system using a H-recycling electrochemical cell.