(535b) Using Techno-Economic Modeling to Chart Pathways to Cost-Competitive Electrochemical CO2 Separation

Deep, society-wide decarbonization is a grand challenge of the 21^st century, requiring the development, manufacture, and deployment of transformative carbon-neutral and carbon-negative technologies on a global scale. Carbon dioxide (CO₂) capture coupled with storage or utilization is projected to play a key role in mitigating and even reversing carbon emissions. Present-day carbon capture processes rely on thermochemical cycles where solvents/sorbents absorb and release CO₂ at lower and higher temperatures, respectively. While functional and available at commercial scale, these embodiments are energetically intensive and typically rely on fossil fuel derived heat for CO₂ desorption, ultimately limiting efficacy. Electrochemical approaches may enable lower energy CO₂ separations, as electrode potential can be modulated to selectively activate sorbents rather than temperature that impacts the entire capture media. Moreover, such systems may enable direct integration of renewables, modular deployment, and operation at (or near) ambient conditions.

To begin to close the gap in understanding the performance and costs of various capture platforms, we have developed modeling frameworks that enable system-level comparisons between conceptual electrochemical CO₂ capture (eCCC) technologies and the incumbent thermochemical, amine-based capture technologies. With a focus on “4–stage” eCCC systems (i.e., comprising of an electrochemical reactor, absorption column, and flash tank), we integrate a reactive absorption model with a simplified electrochemical reactor model to predict the levelized cost of capture of each platform at the pilot plant scale. The model allows for an investigation of the property sets, operating parameters, and target cost factors that result in conditions where electrochemical systems compete with amine-scrubbing systems on an economic basis. Extending further, the model can be used to elucidate performance-determining relationships between constituent components, configurations, and operating envelopes of eCCC when capturing >1 Mtpa CO₂. In addition, the conditions (i.e., gas flow rates, CO₂ concentration, etc.) and scales where eCCC may be better suited to CO₂ separation than existing technologies can be outlined. Ultimately, this modeling effort seeks to inform molecular and device engineering campaigns, providing researchers with a means of navigating the multi-dimensional design space.