Microencapsulation of advanced solvents for carbon capture

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• Novel water-lean solvents like CO2-binding organic liquids (CO2BOLs) and ionic liquids (ILs) are designed for energy-efficient CO2 capture.
• High viscosity and phase instability of these solvents hinder their application in conventional process equipment.
• Encapsulation offers a potential solution to overcome these processing challenges.

Purpose of the Study:

• To develop and demonstrate Micro-Encapsulated CO2 Sorbents (MECS) for improved CO2 capture.
• To address challenges associated with handling viscous or phase-changing CO2-absorbing solvents.
• To investigate the efficacy of encapsulating ionic liquids (ILs) for CO2 capture.

Main Methods:

• Development of micro-encapsulated CO2 sorbents (MECS) with CO2-permeable polymer shells (100-600 μm diameter).
• Screening and custom formulation of polymer shell materials (silicone and acrylate) compatible with water-lean solvents.
• Fabrication of MECS and evaluation of CO2 absorption rates compared to liquid films.

Main Results:

• Identified common polymers incompatible with MECS production.
• Developed promising custom silicone and acrylate formulations for encapsulating water-lean solvents.
• Achieved a 3.5-fold enhancement in CO2 absorption rate using an encapsulated ionic liquid compared to a liquid film.

Conclusions:

• Micro-encapsulation is a viable strategy to overcome processing challenges of advanced CO2 capture solvents.
• Custom silicone and acrylate polymer shells show potential for producing effective MECS.
• Further development of shell materials and fabrication techniques can further improve CO2 absorption rates.