Solid with infused reactive liquid (SWIRL): A novel liquid-based separation approach for effective CO₂ capture

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Economical carbon dioxide (CO2) capture necessitates energy-efficient separation techniques.
• Current liquid-based CO2 capture methods often require water dilution or complex mixing, increasing operational costs.
• Mass transport limitations in mesoporous solid adsorbents hinder efficient CO2 capture.

Purpose of the Study:

• To introduce a novel liquid-infused surface (LIS) approach for immobilizing reactive liquids for CO2 capture.
• To develop a cost-effective and energy-efficient CO2 separation strategy.
• To evaluate the performance of the SWIRL-amine system under realistic flue gas conditions.

Main Methods:

• Utilizing a liquid-infused surface (LIS) to immobilize reactive amines on a textured, thermally conductive solid substrate.
• Employing a high surface-area to volume ratio (A/V) continuum geometry for enhanced gas-liquid contact.
• Testing the SWIRL-tetraethylenepentamine (TEPA) system's CO2 capture capacity and stability at flue gas temperatures and concentrations.
• Investigating the effect of water vapor on CO2 capture performance and system stability.

Main Results:

• The SWIRL approach effectively immobilizes reactive liquids, creating a micrometer-thick liquid layer with high A/V.
• SWIRL-amine eliminates the need for water dilution or costly mixing, simplifying the process.
• SWIRL-tetraethylenepentamine (TEPA) demonstrated stable, high CO2 capture capacities at typical power plant CO2 concentrations and flue gas temperatures.
• The system avoids energy-intensive temperature swings required by other capture methods.
• Water vapor was found to enhance CO2 capacity of SWIRL-TEPA without negatively impacting stability.

Conclusions:

• The SWIRL technology presents a promising, low-energy strategy for economical CO2 capture.
• SWIRL-TEPA offers a stable and efficient alternative to current liquid-based CO2 capture methods.
• The ability to operate at flue gas temperatures and tolerate water vapor makes SWIRL a potentially scalable solution for industrial CO2 emissions reduction.