Theoretical and experimental validation of an electrochemical-mediated integrated system for CO₂ capture and compression

The carbon dioxide capture and compression processes represent the most energy-intensive stages in the carbon capture and storage (CCS) process, which are usually treated independently in the existing studies. Integrating the CO₂ capture and compression stages is a possible way to effectively reduce the compressor size and the total energy consumption of the CCS process. The recent development of electrochemically mediated amine regeneration (EMAR) technology provides a promising approach for this integration due to the strong driving force of the electrochemical reaction and the copper–amine complexation reaction. In this paper, we propose an electrochemical-mediated integrated system for CO₂ capture and compression and verify its pressurized operation performance both theoretically and experimentally. A thermodynamic model was developed to analyze the energy performance of the system and a bench-scale flow-cell system was designed to verify its ability to output CO₂ under pressurized conditions. The thermodynamic modelling results indicated that the energy consumption of the integrated system is significantly affected by different operational paths. At lower pressures, CO₂ bubbles are easier to form and the system tends to operate in 3-steps, higher pressures lead the system to function in 4-steps. Furthermore, the total energy consumption of the CCS process can be reduced by releasing CO₂ at a suitable pressure. The results of the bench-scale flow system indicated that a 40% increase in release pressure resulted in a nearly constant driving voltage and released CO₂ amount, thereby demonstrating its capacity to release pressurized CO₂. In conclusion, the results demonstrate the feasibility of the electrochemical-mediated integrated system, which provide an innovative low-energy pathway to support the achievement of global carbon neutrality.