Advancing integrated CO ₂ electrochemical conversion with amine-based CO ₂ capture: a review

Abstract

This review paper provides an overview of the fundamental and applied aspects of advancing carbon dioxide electrolysis for the integrated amine-based CO ₂ capture and conversion.

Abstract

Carbon dioxide (CO ₂) electrolysis is a promising route to utilise captured CO ₂ as a building block to produce valuable feedstocks and fuels such as carbon monoxide and ethylene. Very recently, CO ₂ electrolysis has been proposed as an alternative process to replace the amine recovery unit of the commercially available amine-based CO ₂ capture process. This process would replace the most energy-intensive unit operation in amine scrubbing while providing a route for CO ₂ conversion. The key enabler for such process integration is to develop an efficient integrated electrolyser that can convert CO ₂ and recover the amine simultaneously. Herein, this review provides an overview of the fundamentals and recent progress in advancing integrated CO ₂ conversion in amine-based capture media. This review first discusses the mechanisms for both CO ₂ absorption in the capture medium and electrochemical conversion of the absorbed CO ₂. We then summarise recent advances in improving the efficiency of integrated electrolysis via innovating electrodes, tailoring the local reaction environment, optimising operation conditions ( e.g., temperatures and pressures), and modifying cell configurations. This review is concluded with future research directions for understanding and developing integrated CO ₂ electrolysers.