Separation of High-Purity C₂H₂ from Binary C₂H₂/CO₂ Using Robust Al-Based MOFs Comprising Nitrogen-Containing...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient separation of acetylene (C2H2) from carbon dioxide (CO2) is crucial for industrial processes.
• Aluminum-based metal-organic frameworks (Al-MOFs) are emerging as promising materials for gas adsorption and separation.

Purpose of the Study:

• To investigate the performance of three nitrogen-containing Al-MOFs (CAU-10pydc, MOF-303, and KMF-1) for C2H2/CO2 separation.
• To identify the key structural features responsible for selective C2H2 adsorption.

Main Methods:

• Synthesis and characterization of three Al-MOFs.
• Gas adsorption isotherms to determine C2H2 and CO2 uptake capacities.
• Dynamic breakthrough experiments for evaluating separation performance.
• Computational simulations (Canonical Monte Carlo, DFT) to analyze pore surface interactions.

Main Results:

• KMF-1 exhibited the highest C2H2/CO2 selectivity (6.31) due to superior C2H2 uptake (7.90 mmol g-1) and lower CO2 uptake (2.82 mmol g-1).
• Dynamic breakthrough experiments confirmed KMF-1's superior separation performance, yielding >99.95% pure C2H2.
• Computational simulations indicated that secondary amine groups in KMF-1 are key to differentiating C2H2 and CO2 adsorption.

Conclusions:

• KMF-1 demonstrates exceptional performance for separating high-purity acetylene from CO2 mixtures.
• The presence of secondary amine groups in KMF-1's pore structure is critical for selective C2H2 adsorption.
• KMF-1 represents a promising adsorbent for practical acetylene/carbon dioxide separation applications.