Regulation of Aminoethylethanolamine (AEEA)-Based Nonaqueous Phase Change Absorbents for Efficient and Energy-Saving CO2 Capture

Abstract

Nonaqueous liquid–liquid CO₂ phase change absorbents (CPCAs) have garnered significant attention due to their potential for efficient and energy-saving CO₂ capture in the amine-scrubbing process. This study introduces a novel nonaqueous CPCA that utilizes aminoethylethanolamine (AEEA) as the main amine absorbent, dimethyl sulfoxide (DMSO) as the organic solvent, and N-ethylmorpholine (NEM) as the phase separator. To mitigate the high viscosity of the rich phase in CPCA, diethanolamine (DEA) is introduced as a viscosity regulator, which reduces the viscosity by 79.3% by weakening the intermolecular hydrogen bonding in the CO₂ products. Notably, the optimized CPCA of A₂₀E₁₀D₄₀N₃₀ demonstrates a high cyclic capacity of 2.94 mol·kg^–1 and a low regeneration energy consumption of 1.79 GJ·t^–1 of CO₂. Overall, the efficient CO₂ capture performance, low regeneration energy consumption, and minimal corrosivity make this CPCA a promising candidate for industrial CO₂ capture applications.