Functionalized and Hybridized ZIF-7 Adsorbents for Ethane-Ethylene Separation
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The separation of light olefins from paraffins is considered as one of the separation processes with the potential to reshape the industrial world, owing to the current energy-intensive practice. Herein, we designed a series of functionalized and hybridized zeolitic imidazolate framework-7 (ZIF-7) adsorbents for ethane/ethylene separation based on pre- and post-synthesis functionalization, organic ligand modification, and hybridization with reduced graphene oxide (rGO). The gate opening mechanism, an intrinsic characteristic of ZIF-7 resulting from the rotation of the organic ligands, particularly benzimidazole, was explored to evaluate the effect of the applied modification strategies on the separation performance. The optimal adsorbent (ZIF-7-rGO-2), a ZIF-7 hybrid with rGO, exhibited a high equilibrium ethane capacity of 3.2 mmol/g at 298 K and 1 bar and an IAST ethane/ethylene selectivity of 4.5 for a 1/15 ( v/v ) mixture. Dynamic breakthrough experiments with a binary ethane/ethylene mixture (1/9, v/v ) revealed cyclability by regeneration solely under inert gas flow at ambient conditions and a substantial time difference of 4.5 min between the elution time of the two gases thus resulting in a high breakthrough selectivity. The purity of the produced ethylene was >99.9%, and its productivity was 0.89 mmol/g, revealing that polymer-grade ethylene could be produced at ambient conditions from ethylene-rich gas stream. These findings provide valuable insights into the intricate dynamics of light olefin/paraffin separation and optimal ZIF-7 configurations, paving the way toward designing energy-efficient adsorption processes for this challenging separation.
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G3290848300, G63039802
OpenAlex ID: W4403933480