Superior gravimetric CO₂ uptake of aqueous deep-eutectic solvent solutions

Area of Science:

• Chemical Engineering
• Environmental Science
• Materials Science

Background:

• Industrial processes generate significant carbon dioxide (CO2) emissions.
• Traditional CO2 capture methods often involve energy-intensive regeneration and material degradation.
• Monoethanolamine (MEA) is a widely used but suboptimal absorbent for CO2 capture.

Purpose of the Study:

• To evaluate a novel deep eutectic solvent (DES) based on [ImCl][EDA] as a CO2 absorbent.
• To compare the performance of the [ImCl][EDA] DES with the industry standard MEA solution.
• To assess key performance metrics including CO2 uptake, kinetics, regeneration enthalpy, and degradation.

Main Methods:

• Preparation of a 30% (w/w) [ImCl][EDA] deep eutectic solvent in water.
• Gravimetric analysis to determine CO2 uptake capacity.
• Kinetic studies to evaluate absorption rates.
• Thermogravimetric analysis (TGA) to assess regeneration enthalpy and degradation.

Main Results:

• The [ImCl][EDA] DES exhibited superior gravimetric CO2 uptake compared to MEA.
• The DES demonstrated desirable absorption kinetics.
• Lower regeneration enthalpy was observed for the [ImCl][EDA] DES.
• The DES showed lesser degradation than the MEA solution under tested conditions.

Conclusions:

• The [ImCl][EDA]-based DES presents a highly effective and stable alternative to MEA for CO2 capture.
• This DES offers significant advantages in terms of efficiency and sustainability for carbon capture technologies.