October 22
@
4:00 PM
–
5:00 PM
Fikile Brushett
Chemical Engineering
Massachusetts Institute of Technology
Cambridge, MA
Towards electrochemical carbon dioxide capture using soluble, redox-active carriers
Fikile Brushett
Deep, society-wide decarbonization is a grand challenge of the 21st 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 desorb CO2 at lower and higher temperatures, respectively. While functional and available at the 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 impact the entire capture media. In addition, such systems may enable direct integration of renewable energy sources, modular deployment, and operation at ambient conditions.
While there are several promising electrochemical approaches for CO2 separation, I will focus on systems that exploit soluble, redox-active carriers with CO2 binding strengths that vary with changes in oxidation state. Within this nascent field, most efforts seek to discover stable carrier molecules and electrolyte formulations that enable high separation capacities and energetically-efficient operation. However, at this early stage of development, modeling frameworks hold value in describing key relationships between molecular properties, cell performance, and system design. Such knowledge may, in turn, inform ongoing molecular and device engineering campaigns, giving researchers a means of estimating carrier molecule effectiveness and reactor performance. In this talk, I will describe our efforts to develop thermodynamic, electrochemical, and techno-economic models to articulate the performance-determining relationships between constituent components, configurations, and operating envelopes of electrochemical CO2 separation systems. I will also provide examples of how these insights gained can focus experimental efforts.