Performance Evaluation of Newly Developed Absorbents for Solvent-Based Carbon Dioxide Capture

Solvent-based absorption using aqueous monoethanolamine (MEA) is the most mature and commercially available carbon dioxide capture technique. However, high capital cost and large energy consumption required for solvent regeneration still remain major disadvantages, which results in delaying the worldwide large-scale deployment of this technology. Several newly developed absorbents have been recently proposed to solve the main issue for the energy-efficient capture process. In this work, several advanced solvents, i.e., aqueous and water-lean amino acid salts (potassium lysinate, potassium prolinate, or potassium sarcosinate) and blends of amines with glycol ethers, were selected as the representatives for aqueous, non-aqueous, and phase-change systems. The CO2 absorption-desorption performance of these absorbents was characterized. The relative heat duty of those CO2-loaded absorbents was also evaluated and compared to conventional aqueous 30 mass % MEA. Preliminary results indicate that non-aqueous and phase-change absorbents investigated in this work have huge potential in reducing energy consumption of regeneration, at about 40-60% reduction.