Unraveling the energy‐saving mechanism of microwave‐enhanced CO ₂ desorption via dielectric swing‐induced hot‐spots

Microwave (MW)‐assisted CO 2 desorption is an emerging energy‐saving technology for absorbents regeneration, however, its industrial application remains constrained by an inadequate understanding of the underlying energy‐saving mechanisms and a lack of quantitative data on energy efficiency. To comprehensively elaborate the mechanism of MW‐enhanced CO 2 desorption, this study develops a theoretical model of MW hot‐spots based on the dielectric swing of the absorbents with or without CO 2 loading. The desorption performance of CO 2 from monoethanolamine (MEA) under MW heating and conventional heating conditions was investigated to validate the proposed model and the mechanism of microscopic enhanced CO 2 desorption. Furthermore, using the obtained desorption kinetic data, a techno‐economic assessment of the MW desorption process was conducted via process simulation. The results reveal that the selective heating effect of MWs significantly reduces the energy consumption of the process by 31.5%, consequently lowering the CO 2 capture cost from $60.8/t CO 2 to $42.8/t CO 2 .