Regeneration capability and mechanism of 2-(Methylamino)ethanol-based water-lean amine absorbent for efficient CO2 capture

Abstract

This investigation innovatively develops a water-lean blended amine system through multidimensional performance evaluation and reaction mechanism elucidation. The experimental protocol commenced with screening MAE (2-(Methylamino)ethanol) blended with five organic amines, where M15D15 (15 wt% MAE + 15 wt% DETA) and M15A15 (15 wt% MAE + 15 wt% AMP) emerged as prime candidates due to their exceptional cyclic capacity and rapid desorption kinetics, respectively. Subsequent phase behavior optimization via n-propanol (PrOH) incorporation revealed critical solvent composition effects. The optimized M15D15P45 formulation (MAE/DETA/PrOH = 15:15:45 wt%) demonstrated remarkable capability metrics: 81.2 % enhancement in CO₂ absorption capacity and 129 % improvement in cyclic capacity compared to benchmark 30 wt% MEA aqueous solution, with regeneration energy consumption reduced to 2.05 GJ·t⁻¹CO₂. Post six absorption–desorption cycles, the system retained 95.2 % initial capacity, showcasing exceptional stability. ¹³C NMR spectral analysis confirmed PrOH’s dual functionality as both phase separation promoter and active reaction participant through carbamate formation. Kinetic profiling further revealed MAE’s superior regeneration responsiveness over DETA. In conclusion, the M15D15P45 absorbent system demonstrates excellent regeneration capability and outstanding stability, with significant potential for future development.