Flow System with Liquid Active Sorbents for Electrochemically Mediated Carbon Capture

Abstract

Within the field of carbon capture, electrochemically driven methods have drawn increasing attention due to their ability to operate at ambient temperature, their efficient scaling, and potentially low energetic cost. An important consideration in such systems is the method of gas contacting to enable efficient CO 2 separation from the feed gas. Previous flow-based electrochemical processes that enable large-area gas contacting and desorption of concentrated CO 2 at a point location all utilize water as the solvent and can require significant water feeds due to high evaporation rates. Here, we demonstrate the use of liquid, redox-active sorbents in a flow system that can decouple the electrode size from gas contacting area. The concept sorbent is a nonvolatile, liquid quinone species that can be reversibly reduced and oxidized to capture and release CO 2 , respectively. In this initial study, we employ the liquid quinone with sodium salts to achieve sorbent capacities near 2.5M CO 2 and couple this sorbent to a ferrocene-derived counter electrolyte in a continuous capture – release process. Through this, we illustrate considerations in the salt choice, counter-electrolyte, and system design to best enable this concept sorbent, and discuss many opportunities for future optimizations.

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Identifiers

DOI

10.1149/ma2022-01272416mtgabs

Journal

ECS Meeting Abstracts

Year

2022