Scaling Supercapacitive Swing Adsorption of CO₂ Using Bipolar Electrode Stacks

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Carbon capture technologies are crucial for mitigating climate change.
• Supercapacitive swing adsorption (SSA) offers a promising electrochemical approach for CO2 removal.
• Bipolar electrode stacks are key components in advancing SSA module design.

Purpose of the Study:

• To investigate the scalability and performance of SSA modules with varying numbers of bipolar electrode pairs.
• To evaluate the impact of module design on CO2 sorption capacity, adsorption rates, and productivity.
• To assess the energy efficiency and consumption of scaled SSA systems.

Main Methods:

• Construction of SSA modules with 2, 4, 8, and 12 bipolar electrode pairs using BPL 4 × 6 activated carbon.
• Testing under simulated flue gas conditions (15% CO2 / 85% N2) at different voltages (2–12 V).
• Measurement of sorption capacities, adsorption rates, productivity, energy efficiency, and energy consumption.

Main Results:

• All SSA modules demonstrated reversible adsorption with consistent capacities (≈58 mmol kg⁻¹) and rates (≈38 µmol kg⁻¹ s⁻¹).
• Module productivity increased significantly with the number of cells, from 70 to 390 mmol h⁻¹ m⁻².
• Energy efficiency improved from 67% to 84%, and energy consumption decreased from 142 to 60 kJ mol⁻¹ as the number of electrodes increased.

Conclusions:

• SSA modules with bipolar electrodes can be scaled effectively without compromising adsorptive performance.
• Increasing the number of bipolar electrodes enhances both productivity and energetic performance of SSA systems.
• The study confirms the viability of scaled bipolar electrode SSA modules for efficient carbon dioxide capture.