Dual-Pore Dodecanuclear Al-Oxo Cluster-Based Bimetallic Isonicotinate Frameworks for Selective Propylene/Ethylene...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Separating ethylene (C2H4) and propylene (C3H6) from methanol-to-olefins (MTO) products is difficult due to similar properties.
• Conventional cryogenic distillation is energy-intensive and costly.

Purpose of the Study:

• Develop cost-effective and efficient adsorbents for C2H4/C3H6 separation.
• Investigate bimetallic isonicotinate aluminum-based metal-organic frameworks (Al12INA-M) for MTO product purification.

Main Methods:

• Synthesis of Al12INA-M (M = Mn, Fe, Co, Cu) with ftw topology.
• Adsorption capacity and selectivity measurements (IAST).
• Dynamic breakthrough experiments and theoretical calculations.

Main Results:

• Al12INA-Fe demonstrated high C3H6 adsorption (7.60 mmol g-1), moderate isosteric heat (29.3 kJ mol-1), and high C3H6/C2H4 selectivity (~8).
• Effective separation of equimolar C2H4/C3H6 mixtures yielding polymer-grade C2H4.
• Low synthetic cost ($345.3 per kg) and purification cost (~$5.44 per liter of C2H4).

Conclusions:

• Al12INA-Fe is a promising, cost-effective adsorbent for C2H4/C3H6 separation.
• Separation mechanism involves molecular sieving and favorable host-guest interactions.
• This adsorbent offers an energy-efficient alternative to cryogenic distillation.