Efficient Separation of C₂H₆/C₂H₄ and C₃H₈/C₂H₆/CH₄ Light Hydrocarbons Using Robust Porous Polymer Networks for C₂H₄...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Efficient production of ultrahigh-purity ethylene (C2H4) and methane (CH4) is critical for industrial processes and alternative energy.
• Current methods like cryogenic distillation are energy-intensive and costly.
• Developing advanced materials for selective gas separation is an ongoing challenge.

Purpose of the Study:

• To develop novel porous polymer networks (PPNs) for the efficient purification of C2H4 and CH4.
• To evaluate the separation performance of four new PPNs (PPN-35, PPN-45, PPN-55, PPN-65) for specific gas mixtures.
• To demonstrate the potential of these PPNs as alternatives to cryogenic distillation.

Main Methods:

• Synthesis and characterization of four porous polymer networks (PPNs).
• Adsorption and Ideal Adsorbed Solution Theory (IAST) selectivity calculations for relevant gas pairs (C2H6/C2H4, C2H6/CH4, C3H8/C2H6, C3H8/CH4).
• Experimental validation using breakthrough experiments to assess purification efficiency and capacity.

Main Results:

• PPN-35, PPN-45, PPN-55, and PPN-65 exhibited high selectivities for C2H4/C2H6 and CH4/C3H8/C2H6 mixtures.
• PPN-35 achieved the highest reported C2H6/C2H4 selectivity (1.67) among PPNs.
• Selectivities for C2H6/CH4, C3H8/C2H6, and C3H8/CH4 surpassed existing sorbent materials.
• Breakthrough experiments demonstrated >99% purity for C2H4 and CH4, validating practical usability.

Conclusions:

• The developed PPNs show exceptional performance in separating light hydrocarbons.
• These materials offer a highly efficient and potentially less energy-intensive alternative to cryogenic distillation.
• This research opens new avenues for utilizing PPNs in industrial gas separation applications.