Ethylene purification in a metal–organic framework over a wide temperature range via pore confinement

Abstract

The separation of C2H4 from C2H6/C2H4 mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework (MOF) BUT-315-a as a C2H6-selective adsorbent for the separation of C2H6/C2H4 gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C2H6 uptake of 97.5 cm3 g−1, giving superior high separation potential ΔQ (2226 mmol L−1) for equimolar C2H6/C2H4 at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C2H6 and the framework. This work highlights a new benchmark material for C2H6/C2H4 separation and provides guidance for designing adsorbent for separation applications.

Keywords

• Metal–organic framework
• Adsorptive separation
• Ethylene purification
• Temperature adaptability
• Pore confinement