Solid Amine Adsorbent Prepared by Molecular Imprinting and Its Carbon Dioxide Adsorption Properties

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Developing efficient adsorbents for carbon dioxide (CO2) capture is crucial for mitigating climate change.
• Solid amine adsorbents offer advantages over liquid systems but often suffer from pore blockage and diffusion limitations.
• Polyethylenimine (PEI) is a promising amine for CO2 adsorption due to its high capacity, but its application in solid adsorbents requires structural optimization.

Purpose of the Study:

• To synthesize a novel solid amine adsorbent with enhanced CO2 adsorption capacity and stability.
• To investigate the mechanism of CO2 imprinting and the role of amine functional groups in adsorption.
• To evaluate the performance of the adsorbent under humid conditions and assess its regeneration capabilities.

Main Methods:

• Preparation of a carbon dioxide imprinted solid amine adsorbent (IPEIA-R) by cross-linking CO2-preadsorbed PEI with glutaraldehyde.
• Characterization of the adsorbent using FTIR, FT-Raman, and 13C NMR spectroscopy.
• Evaluation of CO2 adsorption capacity, regeneration performance, and stability under humid conditions.

Main Results:

• The imprinting process effectively utilized CO2 as a template, and reduction of imino groups enhanced CO2 adsorption.
• The synthesized adsorbent exhibited a high CO2 adsorption capacity of 8.56 mmol/g in the presence of water at 25°C.
• The adsorbent demonstrated excellent regeneration performance, maintaining its capacity after 15 adsorption-desorption cycles, and avoided pore blockage issues.

Conclusions:

• The developed CO2 imprinted solid amine adsorbent shows superior performance compared to traditional PEI-based adsorbents.
• The imprinting strategy and post-synthesis modification are effective in enhancing CO2 capture efficiency and stability.
• This material presents a promising solution for efficient and regenerable carbon capture, particularly under humid industrial flue gas conditions.