Structure Design of Low-Temperature Regenerative Hyperbranched Polyamine Adsorbent for CO₂ Capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Solid amine adsorbents are crucial for CO2 capture.
• Traditional adsorbents often require high temperatures for regeneration, increasing energy costs.
• Developing efficient and low-temperature regenerative adsorbents is essential for practical CO2 capture.

Purpose of the Study:

• To synthesize a novel hydroxy-functionalized hyperbranched polyamine adsorbent (0.16OH-HBPA).
• To evaluate the CO2 adsorption capacity and low-temperature regeneration performance of 0.16OH-HBPA.
• To investigate the mechanism behind the improved regeneration performance.

Main Methods:

• Hyperbranched polymers (HBP) were synthesized via a one-pot reaction.
• HBP was cross-linked and functionalized to create 0.16OH-HBPA.
• CO2 adsorption capacity and regeneration efficiency were tested under various conditions.

Main Results:

• 0.16OH-HBPA demonstrated a high CO2 adsorption capacity of 4.05 mmol/g at 25 °C with 10% CO2 concentration in water.
• The adsorbent achieved 73% alkyl amino utilization efficiency.
• Excellent regeneration performance was observed at 85 °C under pure CO2 gas, significantly lower than traditional adsorbents.

Conclusions:

• The hydroxyl groups in 0.16OH-HBPA cooperatively adsorb CO2, forming stable carbamic acid and suppressing urea formation.
• This mechanism enables low-temperature regeneration, overcoming a key limitation of existing solid amine adsorbents.
• 0.16OH-HBPA presents a promising material for efficient and cost-effective CO2 capture technologies.