Modeling of CO2 Capture by Electro-Swing Reactive Adsorption from Low-Concentration Streams

This article investigates the performance of Faradaic electro-swing reactive adsorption (ESA) for CO2 capture using simulations. Traditional methods such as amine scrubbing face energy efficiency challenges, particularly at low CO2 concentrations. ESA, which uses electricity for CO2 regeneration, offers a promising alternative due to its isothermal operation and scalability. The study models ESA using quinone-based redox-active CO2 carriers in an electrochemical cell with an ionic liquid electrolyte, allowing reversible adsorption and release through voltage control. The model estimates system productivity and energy consumption, considering transport and chemical kinetics. Key findings show that operating parameters, such as applied potential and gas flow rate, have a significant effect on efficiency. Applying a potential of −1.3 V improved the adsorption capacity, reducing CO2 capture time compared to −1.1 V. At a 1% CO2 concentration and a low flow rate, effective capture resulted in a productivity of 1.6 kg/(m3·day) with an energy consumption of 0.6 MWh/tCO2. However, higher gas flow rates reduced capture efficiency due to CO2 transport limitations in the ionic liquid. Optimization of electrode design is essential to improve ESA efficiency.