Foam-driven interface optimization for intensified CO2 absorption: Experimental and molecular insights into surfactant–MEA hybrid systems

Enhancing the CO 2 absorption efficiency of aqueous amine solutions while maintaining low energy penalties remains a central challenge for sustainable post-combustion carbon capture. In this study, a foam-interface regulation strategy is proposed by introducing five typical surfactants into monoethanolamine solutions. By integrating a multiscale approach encompassing dynamic foam analysis, CO 2 absorption-desorption testing, spectroscopic characterization, and molecular simulation, this study elucidates the physical mechanisms through which surfactants enhance CO 2 mass transfer via interfacial regulation. The results showed that the addition of surfactants significantly improved foam stability and interfacial area, increasing carbon dioxide absorption efficiency by up to 20 % and initial absorption rate by approximately 40 % compared to the pure MEA system, with 0.05 wt% being the threshold concentration for most systems. Notably, 13 C nuclear magnetic resonance and Fourier-transform infrared spectroscopy confirmed that the chemical absorption pathway remained unaltered, indicating a physical enhancement mechanism via interfacial structuring. Furthermore, molecular dynamics simulations revealed strengthened hydrogen bonding networks near the H 2 O–surfactant interface. This work demonstrates a low-dosage, interface-driven route to intensify CO 2 absorption without compromising solvent regenerability, offering a promising avenue for sustainable carbon capture process design.