One-Step Ethylene Purification by an Ethane-Screening Metal–Organic Framework

Abstract

Efficient purification of ethylene (C 2 H 4 ) from ethane (C 2 H 6 ) is a crucial but daunting task for the chemical industry given their similar physical natures and molecular dimensions. Reversed capture of C 2 H 6 from C 2 H 6 /C 2 H 4 dual-mixtures can be expected to directly yield high-purity C 2 H 4 through a one-step separation unit, but it remains a daunting challenge. Here, we skillfully target an unusual "electrostatic-driven linker microrotation" (EDLM) in a Zr-MOF through coupling dual-ligands having electron-withdrawing/donating groups (e.g., F and CH 3 motifs). EDLM triggered microrotation of linker geometry and screening sites not only enhanced structural rigidity and hydrophobic nature, etc., but also effectively purified C 2 H 4 through reversely trapping C 2 H 6 . Under ambient conditions, 1 kg of activated 2 adsorbents directly produces 7.2 L of C 2 H 4 with over 99.9%+ purity in a single breakthrough operation starting from the equimolar C 2 H 6 /C 2 H 4 cracked mixtures. Geometrical models and simulations have revealed that EDLM-derived H-bonding interaction and microrotation of linker geometry, synergistically customized C 2 H 6 -selective screening sites and pore inert for reversed C 2 H 6 capture and improved surface hydrophobicity. Adsorption isotherms, modeling simulations, and breakthrough tests based on pressure swing adsorption (PSA) conditions have jointly elucidated the underlying separation properties for C 2 H 4 purification. The enhanced hydrophobic nature, cycling durability, and separation property awarded 2 a new benchmark adsorbent to purify the olefin/paraffin mixtures. KEYWORDS: C 2 H 6 /C 2 H 4 separation, metal−organic framework, electrostatic-driven linker microrotation, C 2 H 4 purification, modeling simulations

Induced‐Fit‐Identification in a Rigid Metal‐Organic Framework for ppm‐Level CO2 Removal and Ultra‐Pure CO Enrichment

“…Ideal adsorbed solution theory (IAST) selectivity was first predicted by fitting the double-site Langmuir-Freundlich (DSLF) models (Table S8). [26] As shown in Figure 4a, 1 a-apz suggests a noticeable IAST selectivity for CO 2 /CO mixtures, yielding an ultrahigh value of 2023 at near-zero coverage and 298 K, which is far superior to wellknown MOFs, including ZJU-HOF-1 (15), [9a] DMOF-1 (55), [4] and HKUST-1 (5), [4] albeit being slightly lower than SIFSIX-3-Ni (4044), [4] which has a quasi-sieving effect. Note that the approach is usually subject to limited requirements or uncertainties; thus, errors may occur due to narrow pores (nonideal gas solution) and structural flexibility.…”

Quasi-Orthogonal Configuration of Propylene within a Scalable Metal–Organic Framework Enables Its Purification from Quinary Propane Dehydrogenation Byproducts

“…Metal–organic frameworks (MOFs), as well-known porous adsorbents, have been extensively explored for gas separation due to their adjustable pore chemistry and structural diversity etc. − In terms of separation mechanisms, it can be roughly divided into thermodynamic separation and nonequilibrium separation. Compared with unilateral thermodynamic equilibrium dominated by binding affinities, the strategies that rely on nonequilibrium separation (including sieving separation and kinetic-driven separation) can be more energy-efficient and realistic given the fact that industrial pressure swing adsorption (PSA), vacuum swing adsorption (VSA), and temperature swing adsorption (TSA) processes are actually operating under nonequilibrium operating conditions.…”

Enhancing Ethane/Ethylene Separation Performance in Two Dynamic MOFs by Regulating Temperature-Controlled Structural Interpenetration

“…Coupled with the coadsorption phenomenon of C 2 H 6 and C 2 H 4 , − it is hard to obtain high-purity C 2 H 4 from the C 2 H 4 -selective MOFs. Thus, paraffin-selective MOFs are more economical for high-purity C 2 H 4 and can be obtained from breakthrough operation in one step. ,− However, only a few C 2 H 6 -selective MOFs have been reported. The leading cause of the reversed adsorption is the multiple C–H···N­(O) hydrogen bonds between the ultramicroporous pore surface and C 2 H 6 molecules.…”