Preparation of a Solid Amine Microspherical Adsorbent with High CO₂ Adsorption Capacity

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Solid-amine materials are crucial for carbon dioxide (CO2) capture from industrial flue gas.
• Developing efficient and regenerable adsorbents is key to mitigating greenhouse gas emissions.

Purpose of the Study:

• To synthesize and characterize a novel solid-amine microsphere for CO2 capture.
• To evaluate the adsorption capacity, kinetics, and regeneration performance of the synthesized material.

Main Methods:

• Synthesis of poly(ethylenimine) (PEI) microspheres via a one-pot W/O emulsion system.
• CO2 adsorption experiments under humid conditions at varying temperatures and pressures.
• Kinetic modeling using the Avrami model to elucidate adsorption mechanisms.
• Swelling and regeneration studies to assess material stability and reusability.

Main Results:

• The PEI microsphere exhibited a high CO2 adsorption capacity of 7.28 mmol/g at 20 °C and 0.1 bar in the presence of moisture.
• The Avrami kinetic model (R2 > 0.99, n between 1-2) indicated both physisorption and chemisorption mechanisms.
• The material demonstrated rapid swelling (equilibrium in 30 s, 271% swelling ratio) and excellent regeneration efficiency (94.63% after six cycles).
• A high breakthrough to saturation capacity ratio of approximately 84% was achieved.

Conclusions:

• The synthesized PEI microsphere is a highly promising adsorbent for CO2 capture from flue gas.
• Its remarkable adsorption capacity, fast kinetics, and efficient regeneration highlight its potential for industrial applications.
• The material's performance under humid conditions and its recyclability make it a viable option for carbon capture technologies.