(353b) On the Good Practices of Electrochemical Reactive CO2 Capture

Upgrading anthropogenic CO₂ from concentrated point sources or directly from the atmosphere is a valuable approach in closing the carbon cycle. Existing processes capture the CO₂, concentrate it into pure gas streams, transport it, and then convert it into fuels and chemicals in a separate process plant. This sequential approach results in higher energy and operating costs which can be reduced by integrating the capture and conversion steps to directly reduce the captured CO₂-bound adduct to value-added products. The capture and direct reduction of the captured CO₂-bound adduct is called Reactive CO₂ Capture (RCC). Understanding of RCC has been obscured by the higher intrinsic complexity of the system. The CO₂ capture media is a complex space of several buffer reactions that allow the co-existence of different carbon species in solution depending on CO₂ loading, temperature, pressure, and pH. In order to design improved capture agents and catalysts for integrated CO₂ capture and conversion, it is essential to identify the carbon source and the primary factors influencing product formation on a RCC catalyst. Using a gas-tight rotating cylinder electrode and leveraging a reaction-transport model developed in our group we characterize our cell to identify the active species undergoing reduction. In this talk, we discuss the reaction-transport model in detail. We also show ways to integrate the understanding of CO₂ loading, temperature, pressure, and pH to determine equilibrium speciation and further discuss the effect that these different conditions have on transport, thermodynamics and kinetics of RCC systems.