Progress, Challenges, and Opportunities in Ionic Liquid-Modified Polymer Membranes for CO₂ Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Anthropogenic CO2 emissions drive the need for effective carbon capture and utilization (CCU).
• Membrane-based CO2 separation is energy-efficient but faces selectivity-permeability trade-offs and plasticization.
• Ionic liquids (ILs) offer high CO2 solubility, stability, and tunability for enhanced membrane performance.

Purpose of the Study:

• To review recent advancements in ionic liquid-functionalized polymer membranes for CO2 separation and conversion.
• To highlight strategies for overcoming limitations in membrane-based CCU.
• To discuss integrated systems for simultaneous CO2 capture and catalytic transformation.

Main Methods:

• Review of recent studies on polymerized ILs, mixed matrix membranes, and hollow fiber configurations.
• Analysis of IL incorporation effects on gas transport, selectivity, and membrane stability.
• Discussion of integrated CO2 capture and conversion systems.

Main Results:

• IL functionalization significantly improves CO2 separation performance (transport and selectivity).
• ILs enhance membrane stability and enable integrated capture-conversion processes.
• Advances include polymerized ILs, mixed matrix membranes, and hollow fiber designs.

Conclusions:

• Ionic liquid-functionalized membranes represent a next-generation platform for CO2 separation and utilization.
• Addressing challenges like IL leaching, polymer compatibility, and thermal stability is crucial for future development.
• Further optimization is needed for industrial implementation of these advanced membrane systems.