Experimental and predictive analysis of deep eutectic solvent gel membranes for efficient CO₂ separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Global warming necessitates efficient Carbon Dioxide (CO2) capture technologies.
• Membrane-based CO2 separation is recognized for its energy efficiency.
• Ionic liquids, while effective, face limitations due to cost and toxicity.

Purpose of the Study:

• To fabricate and evaluate Deep Eutectic Solvents (DES) gel membranes for CO2 separation from CO2/CH4 mixtures.
• To explore DES as a sustainable alternative to ionic liquids in gas separation.
• To investigate the physicochemical properties and gas transport behavior of DES-based membranes.

Main Methods:

• DES gel membranes were fabricated using choline chloride, glycerol, Pebax1657 polymer, and polyvinylidene fluoride supports.
• Fourier transform infrared spectroscopy (FTIR) confirmed DES synthesis.
• X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyzed membrane structure.
• Gas permeation tests (CO2, CH4) were conducted at varying temperatures and pressures.
• Density Functional Theory (DFT) modeled DES-gas molecule interactions.

Main Results:

• The synthesized DES-gel membranes effectively separated CO2 from CO2/CH4 mixtures.
• Highest CO2 permeability values reached 138.98 Barrer (pure gas) and 93.17 Barrer (mixed gas).
• Physicochemical properties of DES were characterized across a temperature range (293.15–343.15 K).

Conclusions:

• DES gel membranes present a viable, cost-effective, and environmentally friendlier alternative to ionic liquid membranes for CO2 capture.
• The study validates the potential of DES in developing advanced membrane technologies for gas separation.