Nickel-Based Metal-Organic Frameworks for Coal-Bed Methane Purification with Record CH4 /N2 Selectivity
Shao-Min Wang1, Mohana Shivanna2, Qing-Yuan Yang1
1School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
Angewandte Chemie (International Ed. in English)
|February 8, 2022
Summary
This study presents novel nickel-based coordination networks for efficient coal-bed methane (CBM) purification. Ni(ina)2 demonstrates record-breaking selectivity for methane over nitrogen, offering a scalable solution for clean energy production.
Area of Science:
- Materials Science
- Chemical Engineering
- Environmental Science
Background:
- Coal-bed methane (CBM) purification is crucial for energy production and mitigating global warming.
- Separating methane (CH4) from nitrogen (N2) in CBM mixtures presents significant challenges.
- Developing advanced materials for selective gas adsorption is an active area of research.
Purpose of the Study:
- To develop and evaluate nickel-based coordination networks for selective CH4/N2 separation.
- To investigate the impact of pore size and chemistry on gas adsorption performance.
- To establish new benchmarks for CH4/N2 separation using metal-organic frameworks (MOFs).
Main Methods:
- Synthesis of four nickel-based coordination networks: Ni(ina)2, Ni(3-ain)2, Ni(2-ain)2, and Ni(pba)2.
- Characterization of pore size and chemical properties of the synthesized materials.
- Gas adsorption and separation experiments to evaluate CH4/N2 selectivity and uptake.
- Dynamic breakthrough experiments to validate separation performance.
- Theoretical calculations and single-crystal structure analysis to elucidate adsorption mechanisms.
Main Results:
- Ni(ina)2 and Ni(3-ain)2 exhibited effective CH4/N2 separation due to optimized pore characteristics.
- Ni(ina)2 achieved the highest reported CH4/N2 selectivity (15.8) and high CH4 uptake (40.8 cm3/g) at ambient conditions.
- Dynamic breakthrough experiments confirmed Ni(ina)2's ability to produce 99% pure CH4.
- Intermolecular interactions and pore affinity were identified as key factors in CH4 adsorption.
Conclusions:
- Nickel-based coordination networks, particularly Ni(ina)2, offer a highly effective strategy for CH4/N2 separation from CBM.
- The developed materials set new performance benchmarks for MOFs and traditional adsorbents in gas separation.
- Ni(ina)2 demonstrates excellent stability, scalability, and cost-effectiveness for potential industrial applications.
