Emerging Breakthroughs in Membraneless Electrochemical Carbon Capture Technologies

M. Rahimi, A. Hassan
University of Houston,
United States

Keywords: carbon capture, electrochemical processes, EMAR, CO2 separation, membraneless

Summary:

Climate change mitigation necessitates the development of effective carbon capture technologies, which include separation and concentration of CO2. Today's maturing thermochemical technologies have exceedingly high energy requirements and rigid form factors that restrict their versatility. Using renewable electricity, rather than heat, as the energy input to drive CO2 separation and concentration provides a compelling alternative to surpass these limitations. A wide range of electrochemical processes was recently developed for carbon capture from various sources, including high-concentration streams such as power plant flue gas and dilute streams like air and seawater. Electrochemical carbon capture (ECC) processes rely on redox reactions to desorb CO2 through an electro-swing mechanism. Due to this unique desorption mechanism, ECCs offer several advantages, including lower energy requirements, eliminating the need to operate at elevated temperatures, and minimizing the rate of absorbent degradation. Additionally, ECCs offer the inherent advantages of electrochemical systems, such as modularity, scalability, and ease of retrofitting. In this presentation, I describe the emerging science and research progress underlying ECC processes and assess their current maturity and trajectory for carbon capture from various sources. An electrochemically mediated amine regeneration process and a pH-mediated method, inspired by vanadium redox flow batteries, will be discussed in further detail. These systems have demonstrated efficient and continuous CO2separation from various sources, paving the way for sustainable carbon capture technologies.