Nitrogen-Containing Heterocyclic Aluminum-Based Metal-Organic Frameworks for Methane Adsorption and Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Coal-bed methane (CBM) contains significant amounts of nitrogen, requiring efficient separation technologies.
• Developing selective adsorbents for methane (CH4) and nitrogen (N2) separation is crucial for CBM utilization.

Purpose of the Study:

• To synthesize novel nitrogen-containing heterocyclic aluminum-based metal-organic frameworks (MOFs).
• To evaluate their performance in selective CH4/N2 separation for CBM applications.
• To investigate the adsorption mechanisms using computational simulations.

Main Methods:

• Aqueous solvent reflux method for MOF synthesis.
• Gas adsorption experiments at 273 K and 1 bar.
• Dynamic breakthrough experiments for separation performance evaluation.
• Grand Canonical Monte Carlo (GCMC) and Density Functional Theory (DFT) simulations.

Main Results:

• Al-PzDC demonstrated superior CH4 adsorption capacity (43.99 cm3/g) and selectivity over Al-PyDC.
• Dynamic breakthrough tests confirmed excellent CH4/N2 separation efficiency.
• Al-PzDC exhibited high reusability over 10 adsorption-desorption cycles.
• Simulations revealed that nitrogen-rich Al-PzDC enhances CH4 adsorption density and selectivity.

Conclusions:

• Al-PzDC is a promising material for selective CH4/N2 separation from CBM.
• The material's structure and nitrogen content contribute to its high adsorption capacity and selectivity.
• The developed MOFs offer a sustainable solution for CBM purification.