CO2 capture and electrochemical upgrade of MEA-based solution: Life cycle assessment and techno-economic analysis

Monoethanolamine (MEA), used as the capturing solvent, significantly enhances CO2 absorption efficiency, representing a promising advancement in the electrochemical conversion of CO2 into value-added products. Assessing the economic and environmental feasibility of this technology emerges as an imperative step along its industrialization process. Here we conducted the life cycle assessment and techno-economic analysis of the approach of direct electrochemical conversion of MEA-based solutions, as well as alternative gaseous CO2 and (bi)carbonate electrolysis systems. The results reveal that the electrochemical CO2 reduction process is the determining factor in the energy consumption distribution among the various systems. And the direct electrochemical conversion of MEA-based solutions offers enhanced energy and environmental benefits compared to alternative pathways. The MEA-based system, while exhibiting a higher electrolysis energy consumption of 25.61 GJ, also achieves the highest energy production of 10.77 GJ. The net energy ratio (the ratio of the net energy input to the energy output) and net greenhouse gas emissions of MEA-based systems stand at 2.5 and − 0.761 t CO2-eq/t CO2, respectively, representing the lowest among the three systems assessed. In addition, its system net present value slightly surpasses that of the other systems, indicating promising prospects for industrialization. Furthermore, sensitivity analysis reveals that operating parameters such as current density and cell voltage are pivotal factors in MEA-based systems, with the former determining the required electrolysis cell area and the latter dictating the energy consumption during electrolysis. This study emphasizes the environmental and economic viability of MEA-based solutions direct electrolysis, offering a framework for its industrialization and future advancements.