Energy-intensive Cryogenic Distillation Research Articles

A novel hydrophobic carborane-hybrid microporous material for reversed C2H6 adsorption and efficient C2H4/C2H6 separation under humid conditions.

Since ethylene (C2H4) is important feedstock in the chemical industry, developing economical and energy-efficient adsorption separation techniques based on ethane (C2H6)-selective adsorbents to replace the energy-intensive cryogenic distillation is highly demanded, which however remains a daunting challenge. While previous anionic boron cluster hybrid microporous materials display C2H4-selective features, we herein reported that the incorporation of a neutral para-carborane backbone and aliphatic 1,4-diazabicyclo[2.2.2]octane (DABCO) enables the reversed adsorption of C2H6 over C2H4. The generated carborane-hybrid microporous material ZNU-10 (ZNU = Zhejiang Normal University) is highly stable in humid air and maintains good C2H6/C2H4 separation performance under high humidity. Gas loaded single crystal structure and density-functional theory (DFT) calculations revealed that the weakly polarized carborane and DABCO within ZNU-10 induce more specific C-Hδ+⋯Hδ--B dihydrogen bonds and other van der Waals interactions with C2H6, while the suitable pore space allows the high C2H6 uptake. Approximately 14.5 L kg-1 of polymer grade C2H4 can be produced from simulated C2H6/C2H4 (v/v 10/90) mixtures under ambient conditions in a single step, comparable to those of many popular materials.

Bromine functionalization of metal–organic frameworks to improve ethane/ethylene separation

Metal–organic frameworks (MOFs) have undergone extensive study as ethane-selective adsorbents for ethane/ethylene (C2H6/C2H4) separation, a process currently conducted through energy-intensive cryogenic distillation in the petrochemical industry. Herein, we present the effect of functionalization using bromine, known for its high polarizability, on the C2H6-selective adsorption properties of MOF. This approach, based on the slightly larger polarizability of C2H6 compared to C2H4, was systematically investigated using three isostructural MOFs: DMOF-1, DMOF-1-Br, and DMOF-1-Br2, featuring 1,4-benzenedicarboxylate, 2-bromo-1,4-benzenedicarboxylate, and 2,5-dibromo-1,4-benzenedicarboxylate ligands, respectively. While their C2H6/C2H4 selectivity, based on the ideal adsorbed solution theory, increased (from 1.51 to 1.75 at 298 K and 100 kPa for the 1/1 (v/v) mixture) with the rising Br content, breakthrough experiments revealed that DMOF-1-Br achieves the highest high-purity (>99.95 %) C2H4 productivity (9.7 LSTP kg−1 at 298 K and 100 kPa for the 1/1 mixture and 22.2 LSTP kg−1 for the 1/15 mixture). This accomplishment is attributed to the appropriate bromine functionalization. Further insight into their C2H6-selective adsorption behavior was gained through canonical Monte Carlo and dispersion-corrected density functional theory simulations.

Adaptive Pore Opening to Form Tailored Adsorption Sites in a Cooperatively Flexible Framework Enables Record Inverse Propane/Propylene Separation.

A proposed low-energy alternative to the separation of alkanes from alkenes by energy-intensive cryogenic distillation is separation by porous adsorbents. Unfortunately, most adsorbents preferentially take up the desired, high-value major component alkene, requiring frequent regeneration. Adsorbents with inverse selectivity for the minor component alkane would enable the direct production of purified, reagent-grade alkene, greatly reducing global energy consumption. However, such materials are exceedingly rare, especially for propane/propylene separation. Here, we report that through adaptive and spontaneous pore size and shape adaptation to optimize an ensemble of weak noncovalent interactions, the structurally responsive metal-organic framework CdIF-13 (sod-Cd(benzimidazolate)2) exhibits inverse selectivity for propane over propylene with record-setting separation performance under industrially relevant temperature, pressure, and mixture conditions. Powder synchrotron X-ray diffraction measurements combined with first-principles calculations yield atomic-scale insight and reveal the induced fit mechanism of adsorbate-specific pore adaptation and ensemble interactions between ligands and adsorbates. Dynamic column breakthrough measurements confirm that CdIF-13 displays selectivity under mixed-component conditions of varying ratios, with a record measured selectivity factor of α ≈ 3 at 95:5 propylene:propane at 298 K and 1 bar. When sequenced with a low-cost rigid adsorbent, we demonstrated the direct purification of propylene under ambient conditions. This combined atomic-level structural characterization and performance testing firmly establishes how cooperatively flexible materials can be capable of unprecedented separation factors.

Precise molecular sieving of ethylene from ethane using triptycene-derived submicroporous carbon membranes.

Replacement or debottlenecking of the extremely energy-intensive cryogenic distillation technology for the separation of ethylene from ethane has been a long-standing challenge. Membrane technology could be a desirable alternative with potentially lower energy consumption. However, the current key obstacle for industrial implementation of membrane technology is the low mixed-gas selectivity of polymeric, inorganic or hybrid membrane materials, arising from the similar sizes of ethylene (3.75 Å) and ethane (3.85 Å). Here we report precise molecular sieving and plasticization-resistant carbon membranes made by pyrolysing a shape-persistent three-dimensional triptycene-based ladder polymer of intrinsic microporosity with unparalleled mixed-gas performance for ethylene/ethane separation, with a selectivity of ~100 at 10 bar feed pressure, and with long-term continuous stability for 30 days demonstrated. These submicroporous carbon membranes offer opportunities for membrane technology in a wide range of notoriously difficult separation applications in the petrochemical and natural gas industry.

Process modeling and optimization of vacuum pressure swing adsorption for ethane and ethylene separation using Cu(Qc)2 MOF

The separation of ethylene from ethane/ethylene mixtures is of prime significance, and replacing the energy-intensive cryogenic distillation used in the petrochemical industry is challenging. The aim of this study is to separate ethane and ethylene using a vacuum pressure swing adsorption (VPSA) process on a Cu(Qc)2 metal–organic framework (MOF) synthesized as a spheroidal adsorbent. To quantify the adsorption equilibrium, single isotherms of ethane and ethylene were measured at 283 and 298 K up to 5 bar. A Quadratic Langmuir adsorption model was employed to predict equilibrium adsorption. Dynamic adsorption experiments were conducted for a single-component and a binary mixture of different feed compositions and flow rates. The mass-transfer coefficients of ethane and ethylene were estimated to be 0.1 sec−1 and 1.0 sec−1, respectively. Based on these parameters, a two-bed, five-step VPSA mathematical model was developed, and the nominal operating conditions were determined from the length of the unused bed. It showed ethylene purity, recovery, and productivity of 99.68 mol%, 65.28%, and 1.84 mol/kg/hr. Sensitivity analyses of purity and recovery were performed using six critical operating variables. The time and rate of the rinse step had the most significant influence on the results, followed by those of the PU, AD and BLW steps. The particle swarm optimization methodology was applied to optimize the operating variables to maximize ethylene recovery. After optimization, the ethylene purity, recovery, and productivity were attained at 99.60 mol%, 76.57%, and 1.98 mol/kg/hr.

Ionic liquid – grafted mesoporous silica exhibiting reverse selectivity for ethane/ethylene separation

Development of paraffin-selective adsorbents for the separation of ethane/ethylene mixtures, as an alternative technology to the energy-intensive cryogenic distillation, is challenging. Herein, we report surface-functionalized mesoporous silica adsorbents exhibiting reverse selectivity prepared by controlled in-situ synthesis of paraffin-selective ionic liquids (ILs) onto the pre-silanized surface of MCM-41 mesoporous silica. The surface modification switched the selectivity of the adsorbents from being inherently olefin-selective to becoming paraffin-selective, due to the enhanced van der Waal’s interactions between the grafted IL functionalities and the ethane molecules. A range of silica-based adsorbents functionalized with ILs of different loadings and anion and cation types were synthesized, characterized and investigated for their ethane/ethylene adsorption behavior. In addition to reversing the selectivity yielding values of up to 3.4 for ethane over ethylene, the adsorbents exhibited low isosteric heat of adsorption, indicatively 12 kJ/mol for ethane, while their performance was stable upon pressure swing adsorption and breakthrough cyclic testing. Dynamic packed bed experiments with ethane/ethylene mixtures demonstrated a breakthrough ethylene productivity of up to 1.2 mmol/g with a breakthrough selectivity of 2.4.

Ag+ anchored on sulfonic functionalized mesoporous silica towards efficient liquid phase Olefin-Paraffin separation

Separation of olefin-paraffin gas mixtures has attracted enormous research endeavors as a replacement of the currently used, energy-intensive cryogenic distillation process, while liquid phase olefin-paraffin separation has remained less exploited. The challenge lies in that the difference in physical properties between C6-C8 olefins and paraffins tend to diminish as C = C bond fraction becomes smaller when alkyl chain grows longer. On the other hand, satisfactory adsorption capacity for these bulky molecules requires the use of porous materials beyond microporosity, i.e., mesoporous materials with large pore volume and size, which, nonetheless, lack adsorption selectivity to guarantee satisfactory separation factors. Here, we demonstrate that functionalization of mesoporous silica MCM-41 surface by –COO-, -Ph-SO3- and -SO3- functional groups can be used to immobilize Ag+, which turns the otherwise unselective porous solid into an olefin selective molecular sieving material suitable for liquid phase binary mixture separations. The results underline that ionically anchored Ag+ with intact complexation orbitals outperform coordinatively immobilized Ag+ (on –NH2 or -SH groups), in terms of anti-leaching property, olefin separation factor, as well as recyclability. Small mesopore size can boost olefin adsorption selectivity as accommodated olefins compressed the available space for access of paraffins. Adsorption evaluation for binary C6 to C8 olefin-paraffin mixtures separations discloses that the total adsorption capacity declines, while the separation factor increases, with increasing molecule size.

Highly-selective xenon–krypton separation using hydrate-based technology

Xenon (Xe) and krypton (Kr) are used in many important industries such as lighting, lasers, double glazing for insulation, and medicine. As Xe and Kr are found in extremely low concentrations in the atmosphere, only small quantities of the mixture of these gases are obtained as byproducts from air separation processes. As the further separation of Kr from Xe is achieved via a costly energy-intensive cryogenic distillation method, the development of a new cost-effective approach for Xe–Kr separation is essential. In this study, we demonstrated that clathrate hydrates can be used as a promising Xe trap to separate a Xe–Kr mixture and produce Kr-rich vapors. The Xe and Kr guest distributions in mixed clathrate hydrates were experimentally identified using powder X-ray diffraction, solid-state 129Xe NMR spectroscopy, and gas chromatography. The mixed Xe + Kr hydrates have a Pm3¯n structure, termed structure I (sI), regardless of the concentration of Xe in the feed vapor in the range of 3% to 100%, and the sI hydrate selectively captures Xe from the feed mixture. The phase equilibria of the mixed Xe + Kr hydrates were also investigated, and it was confirmed that the hydrate-based Xe–Kr separation process requires milder temperature conditions than the cryogenic distillation process. Overall, the findings in this work suggest that the hydrate-based Xe–Kr separation process is an excellent alternative to the energy-intensive cryogenic distillation method.

A Microporous Metal-Organic Framework with Unique Aromatic Pore Surfaces for High Performance C2 H6 /C2 H4 Separation.

Developing adsorptive separation processes based on C2 H6 -selective sorbents to replace energy-intensive cryogenic distillation is a promising alternative for C2 H4 purification from C2 H4 /C2 H6 mixtures, which however remains challenging. During our studies on two isostructural metal-organic frameworks (Ni-MOF 1 and Ni-MOF 2), we found that Ni-MOF 2 exhibited significantly higher performance for C2 H6 /C2 H4 separation than Ni-MOF-1, as clearly established by gas sorption isotherms and breakthrough experiments. Density-Functional Theory (DFT) studies showed that the unblocked unique aromatic pore surfaces within Ni-MOF 2 induce more and stronger C-H⋅⋅⋅π with C2 H6 over C2 H4 while the suitable pore spaces enforce its high C2 H6 uptake capacity, featuring Ni-MOF 2 as one of the best porous materials for this very important gas separation. It generates 12 L kg-1 of polymer-grade C2 H4 product from equimolar C2 H6 /C2 H4 mixtures at ambient conditions.

Pure Silica with Ordered Silanols for Propylene/Propane Adsorptive Separation Unraveled by Three-Dimensional Electron Diffraction.

Adsorptive separation of propylene (C3H6) from propane (C3H8), which could deal with energy-intensive cryogenic distillation technologies, remains challenging due to their similar physiochemical properties. Herein, we present a pure silica zeolite with ordered silanols (OSs), whose crystallographic structure was unraveled by the advanced three-dimensional electron diffraction (3D ED), displaying the highly efficient separation of propylene from propane under ambient conditions. The 3D ED technique enables us to investigate its 8-ring pore opening transformation from the round one to the elliptical one during the removal of organic structure-directing agents. Such unique elliptical 8-ring pore openings can exclude larger-size propane and only adsorb propylene. Its C3H6/C3H8 separation performance is also confirmed by column breakthrough experiments, showing a high dynamic adsorption capacity of 53.36 cm3 g-1 for C3H6 but negligible C3H8 under ambient conditions. The dynamic capacity for C3H6 is superior to that of the well-known pure silica DDR-type zeolite (31.07 cm3 g-1). The density functional theory calculation demonstrates that the adsorbed propylene is distributed in the heart-shaped cavity and has a weak interaction with the OSs.

Optimal Binding Affinity for Sieving Separation of Propylene from Propane in an Oxyfluoride Anion-Based Metal-Organic Framework.

Highly efficient adsorptive separation of propylene from propane offers an ideal alternative method to replace the energy-intensive cryogenic distillation technology. Molecular sieving-type separation via high-performance adsorbents is targeted for superior selectivity, but the limit in adsorption capacity remains a great challenge. Here, we report an oxyfluoride-based ultramicroporous metal-organic framework UTSA-400, [Ni(WO2F4)(pyz)2] (pyz = pyrazine), featuring one-dimensional pore channels that can accommodate the propylene molecules with optimal binding affinity while specifically excluding the propane molecules. The exposed oxide/fluoride pairs in UTSA-400 serve as strong functional sites for strengthened propylene-host interactions, accounting for a significantly enhanced propylene uptake, while the propane molecules are excluded due to the regulated host framework dynamics. The strong propylene binding enables near-saturation of propylene in the pore confinement at ambient conditions, leading to full utilization of pore space and superior packing density. Combined in situ infrared spectroscopy measurements and dispersion-corrected density functional theory calculations clearly unveil the nature of boosted host-guest binding. Direct production of polymer-grade (>99.5%) propylene with remarkable dynamic productivity is demonstrated by column breakthrough experiments. This work presents an example of pore engineering with atomic precision to break the trade-off in adsorptive separation through guest binding optimization.

Nitrogen rejection in natural gas using NaZSM-25 zeolite.

Natural gas reservoirs usually contain considerable amounts of nitrogen (N2). Methane (CH4) as the main component in natural gas must be purified before transferring to the pipeline or storing as liquified natural gas (LNG). Currently, energy-intensive cryogenic distillation is the only industrial approach for N2 rejection in natural gas. The adsorption process based on a N2-selective adsorbent can minimize the separation cost. However, the search for an adsorbent that can selectively reject N2 in natural gas has lasted for decades. Here, we report a microporous zeolite called NaZSM-25 capable of adsorbing N2 over CH4 with an exceptional selectivity of 47 at room temperature that outperforms all previously known N2-selective adsorbents. At 295 K and 100 kPa, the N2 and CH4 uptakes on NaZSM-25 were 0.25 and 0.005 mmol g-1, respectively. CH4 showed negligible external surface adsorption in the whole temperature range of 273-323 K. Theoretical studies through replica exchanged Monte Carlo, molecular dynamics, and ab initio density functional theory (DFT) proved the diffusion limitation of CH4 as a result of 8-membered ring (8MR) pore opening deformation by Na+ cation. The DFT results showed the diffusion energy barriers of 63 and 96 kJ mol-1 for N2 and CH4, respectively, when passing an 8MR occupied with a Na+. NaZSM-25 is a promising adsorbent to be utilized in a pressure swing adsorption process at room temperature to minimize the energy consumption in N2 rejection units.

Boosting Ethane/Ethylene Separation by MOFs through the Amino‐Functionalization of Pores

Adsorption technology based on ethane-selective materials is a promising alternative to energy-intensive cryogenic distillation for separating ethane (C2 H6 ) and ethylene (C2 H4 ). We employed a pore engineering strategy to tune the pore environment of a metal-organic framework (MOF) through organic functional groups and boosted the C2 H6 /C2 H4 separation of the MOF. Introduction of amino (-NH2 ) groups into Tb-MOF-76 not only decreased pore sizes but also facilitated multiple guest-host interactions in confined pores. The NH2 -functionalized Tb-MOF-76(NH2 ) has increased C2 H6 and C2 H4 uptakes and C2 H6 /C2 H4 selectivity. The results of experimental and simulated transient breakthroughs reveal that Tb-MOF-76(NH2 ) has significantly improved one-step separation performance for C2 H6 /C2 H4 mixtures with a high C2 H4 (>99.95 %) productivity of 17.66 L kg-1 compared to 7.53 L kg-1 by Tb-MOF-76, resulting from the suitable pore confinement and accessible -NH2 groups on pore surfaces.

A Metal-Organic Framework with Nonpolar Pore Surfaces for the One-Step Acquisition of C2 H4 from a C2 H4 and C2 H6 Mixture.

Because C2 H4 plays an essential role in the chemical industry, economical and energy-efficient separation of ethylene (C2 H4 ) from ethane (C2 H6 ) is extremely important. With the exception of energy-intensive cryogenic distillation, there are few one-step methods to obtain polymer-grade (≥99.95 % pure) C2 H4 from C2 H4 /C2 H6 mixtures. Here we report a highly stable metal-organic-framework (MOF) FJI-H11-Me(des) (FJI-H=Hong's group in Fujian Institute of Research on the Structure of Matter) which features one-dimensional hexagonal nonpolar pore surfaces constructed by aromatic rings and alkyl groups. This FJI-H11-Me(des) adsorbs C2 H6 rather than C2 H4 between 273 and 303 K. Practical breakthrough experiments with C2 H4 containing 1 % C2 H6 have shown that FJI-H11-Me(des) can realize the acquisition in one-step of polymer-grade, 99.95 % pure C2 H4 under various conditions including different gas flow rates, temperatures and relative humidity.

Superb storage and energy saving separation of hydrocarbon gases in boron nitride nanosheets via a mechanochemical process

Light hydrocarbon olefin and paraffin gas mixtures are produced during natural gas or petrochemical processing. The petrochemical industry separates hydrocarbon gas mixtures by using an energy-intensive cryogenic distillation process, which accounts for 15% of global energy consumption [1]. The development of a new energy-saving separation process is needed to reduce the energy consumption. In this research, we develop a green and low energy mechanochemical separation process in which boron nitride (BN) powders were ball milled at room temperature in the atmosphere of an alkyne or olefin and paraffin mixture gas. BN selectively adsorbs a much greater quantity of alkyne and olefin gas over paraffin gases, and thus the paraffin gas is purified after the ball milling process. The adsorbed olefin gas can be recovered from the BN via a low-temperature heating process. The mechanochemical process produces extremely high uptake capacities of alkyne and olefin gases in the BN (708 cm3/g for acetylene (C2H2) and 1048 cm3/g for ethylene (C2H4)) respectively. To the best of our knowledge, assisted by ball milling, BN nanosheets have achieved the highest uptake capacities for alkyne/olefin gases, which are superior to all other materials reported so far. Chemical analysis reveals that large amounts of olefin gases were quasi-chemically adsorbed on the in-situ formed BN nanosheets via C–N bond formation, whereas small amount of paraffin gases was physically adsorbed on BN nanoparticles. This scalable mechanochemical process has great potential as an industrial separation method and can realize substantial energy savings.

Molecular Sieving of Propylene from Propane in Metal-Organic Framework-Derived Ultramicroporous Carbon Adsorbents.

The development of adsorption-based separation processes alternative to the energy-intensive cryogenic distillation for a mixture of propylene and propane remains essential but challenging in gas industries. Molecular sieving separation of C3H6/C3H8 on stable carbon adsorbents appeals to be promising, while it is quite challenging to realize due to the random distributions and arrangements of the internal pores in common carbons. Herein, a series of polysaccharide-based CD-MOF-derived ultramicroporous carbon adsorbents with their pore size tuned at a subangstrom level were prepared. Molecular sieving separation of C3H6/C3H8 was realized on the optimal C-CDMOF-2-700 owing to the delicate structure with an appropriate pore size (5.0 Å). Besides, C-CDMOF-2-700 exhibited a high C3H6 uptake of 1.97 mmol g-1 under ambient conditions. An ultrahigh uptake ratio of C3H6/C3H8 at 1.0 kPa (403) was also achieved, outperforming all reported adsorbents. Kinetic adsorption tests and breakthrough experiments further demonstrate this well-designed carbon adsorbent to be promising in industrial C3H6/C3H8 separation.

Ionic Liquid Stabilizes Olefin Facilitated Transport Membranes Against Reduction.

Separation of olefins from their paraffin analogs relies on energy-intensive cryogenic distillation. Facilitated transport-based membranes that reversibly and selectively bind olefins, but not paraffins, could save considerable amounts of energy. However, the chemical instability of the silver ion olefin-binding carriers in such membranes has been a longstanding roadblock for this approach. We discovered long-term carrier stability against extended exposure to hydrogen, a common contaminant in such streams. Based on UV/Vis absorption and Raman spectroscopy, along with XRD analysis results, certain ionic liquids solubilize silver ions, and anion aggregates surrounding the silver ion carriers greatly attenuate their reduction by hydrogen. Here, we report the stability of olefin/paraffin separation properties under continuous exposure to high pressure hydrogen, which addresses a critical technical roadblock in membrane-based olefin/paraffin separation.

A strongly hydrophobic ethane-selective metal-organic framework for efficient ethane/ethylene separation

The removal of ethane (C2H6) from ethylene (C2H4) is of great importance to afford polymer-grade C2H4 with purity greater than 99.95% as feedstock to produce polyethylene. Adsorptive separation with C2H6-selective metal-organic frameworks (MOFs) can directly produce high-purity C2H4, which has shown bright prospects for replacing the energy-intensive cryogenic distillation. Herein, we demonstrate a robust zirconium MOF possessing hydrophobic pores and oxygen-rich groups, namely MOF-841, can preferentially adsorb C2H6 over C2H4. Experimental adsorption isotherms and breakthrough show high separation performance for the gas mixture of C2H6 and C2H4 due to ultrahigh C2H6 uptake capacity (4.7 mmol/g) and distinctive C2H6/C2H4 uptake ratio (1.35) of MOF-841 at 298 K and 100 kPa. Computational studies reveal that aromatic rings and carboxylate oxygen atoms pointing towards the pore ascribed to trapping C2H6 through synergistic effects arising from multiple van der Waals interactions including C-H∙∙∙π and C-H···O, which are more potent than C2H4-framework interactions.

Separation of propylene and propane with pillar-layer metal–organic frameworks by exploiting thermodynamic-kinetic synergetic effect

• M(AIP)(BPY) 0.5 (M = Co, Ni, and Zn) showed efficient C 3 H 6 /C 3 H 8 separation. • The separation mechanism was based on the thermodynamic-kinetic synergetic effect. • Ni(AIP)(BPY) 0.5 had the highest C 3 H 6 /C 3 H 8 uptake ratio of 4.26 at 298 K and 1 bar. Efficient adsorption separation of propylene (C 3 H 6 ) and propane (C 3 H 8 ) can largely lower the energy consumption compared to the current energy-intensive cryogenic distillation. Herein, we report an isoreticular family of pillar-layer metal–organic frameworks (MOFs), M(AIP)(BPY) 0.5 (M = Co, Ni, and Zn), for efficient C 3 H 6 /C 3 H 8 separation by simultaneously exploiting thermodynamic and kinetic effects, circumventing disadvantages of each separation mechanism. The three MOFs feature an open metal site for each metal node and uniform but narrow one-dimensional (1D) channels, offering strong binding sites toward C 3 H 6 via π-complexations while obstructing the diffusion of bulkier C 3 H 8 . The Ni-MOF shows the best separation performance based on the highest thermodynamic and kinetic C 3 H 6 /C 3 H 8 selectivities, further verified by computational simulations. Ni(AIP)(BPY) 0.5 has a moderate C 3 H 6 uptake of 1.94 mmol/g but a remarkably high C 3 H 6 /C 3 H 8 uptake ratio of 4.26 at 298 K and 1 bar. Efficient C 3 H 6 /C 3 H 8 separation, good recyclability, moisture and water stability of Ni(AIP)(BPY) 0.5 are confirmed.

Energy efficient ethylene purification in a commercially viable ethane-selective MOF

• Cu(BDC)(DMF) using BDC as a cheap ligand was prepared using a simple and easy-to-scale up method. • Cu(BDC) simultaneously meets the requirements of high C 2 H 6 uptake and excellent ethane/ethylene separation selectivity. • Cu(BDC) exhibits excellent thermal stability and could be stored at room temperature for>1 year. • Cu(BDC) shows excellent separation ability with superior regeneration capability. Separating ethane (C 2 H 6 ) from ethylene (C 2 H 4 ) using ethane-selective adsorbents to replace energy-intensive cryogenic distillation technology is an important energy-saving method in the petrochemical industry to obtain high purity C 2 H 4 . Limited to the low separation efficiency in current commercial materials, it is very urgent and promising to fabricate such alkane selective adsorbents using cheap ligands and simple synthesis methods, which have characteristics such as stable structure, high C 2 H 6 uptake, and adsorption selectivity. In this work, we have used one of the cheapest ligands (terephthalic acid, H 2 BDC) to prepare Cu(BDC)(DMF) via a simple and easy-to-scale up solvothermal method. The activated Cu(BDC) exposed diamond-shaped one-dimensional pores form a stronger affinity with C 2 H 6 than C 2 H 4 through the double function of C-H∙∙∙π interactions and C-H∙∙∙O hydrogen bonds. Benefiting from the difference in these interactions, Cu(BDC) exhibited a higher adsorption capacity of C 2 H 6 (51.5 cm 3 /g) compared to C 2 H 4 (45.1 cm 3 /g) at 1 bar and 298 K, which resulted in high adsorption selectivity (2.0) for the C 2 H 6 /C 2 H 4 mixture (50/50, v/v). Breakthrough experiments indicated that Cu(BDC) successfully achieved the removal of C 2 H 6 from C 2 H 6 /C 2 H 4 (50/50 and 10/90, v/v) mixtures to obtain high purity C 2 H 4 (> 99.99%) using a one-step separation process. When compared with the benchmark materials, Fe 2 (O 2 )(dobdc) and NIIC-20, Cu(BDC) had the advantages of much lower preparation cost and enhanced structural stability. These comprehensive properties indicated that Cu(BDC) with a commercially viable price and synthesis process, could be potentially used for the C 2 H 6 removal step during the production of high purity C 2 H 4 .