INORGANIC CHEMISTRY COMMUNICATIONS
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2024
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IF 4.4
Wei Li,Jingyun Wang,Mengmeng Han,Shanshan Xu
Obtaining pure clean energy methane (CH 4 , 3.80 Å) from natural gas is a great challenge task at present due to the similar kinetic diameter with nitrogen (N 2 , 3.64 Å). Herein, a well-defined rod-like bimetallic MOF (Cu 0.5 Ca 0.5 -SBMOF) with an excellent adsorption performance for CH 4 was successfully prepared and blended as filler with Matrimid® 5218 (PI) for preparing mixed matrix membranes (Cu 0.5 Ca 0.5 -SBMOF@PI MMMs). In the separation experiment of N 2 /CH 4 binary gas mixture, both filler loadings and trans -membrane pressure have significant effects on the separation performance of MMMs. When the filler loading is 20 wt%, Cu 0.5 Ca 0.5 -SBMOF@PI MMMs exhibits an excellent separation performance with a separation factor of CH 4 /N 2 up to 17.03, and the permeability of 22.57 barrer for N 2 , which significantly preceded the most reported MMMs. Moreover, the prepared MMMs also show excellent stability. This work has taken an important step towards practical application in the field of separating N 2 /CH 4 gas mixture using MMMs method.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2022
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IF 5.876
Xiaoli Ding,Yongfu Tang,Hongyong Zhao,Qingping Xin,Yuzhong Zhang
Hollow SAPO-34 with an average particle size of ca .370 nm was synthesized by selective etching its precursor under the controlled alkaline condition. Subsequently, freestanding mixed matrix membranes were synthesized by UV-induced in-situ polymerization of the mixture of hollow SAPO-34, the fluorinated monomer , and the trifunctional cross-linker. The structure and the physical characteristic of hollow SAPO-34 and membranes were characterized by scan electron microscope, wide-angle X-ray diffraction, etc. The effect of the hollow SAPO-34 loading amount on the gas permeation-separation performance of mixed matrix membranes was investigated. The results showed that hollowing out SAPO-34 improved the N 2 /CH 4 sorption selectivity and converted the crystals from preferential adsorption of N 2 to preferential adsorption of CH 4 , the incorporation of hollow SAPO-34 into membranes increased the N 2 /CH 4 solubility selectivity and the permeability. The optimal membrane exhibited a 39-fold increase in N 2 permeability from 6.9 × 10 −13 to 2.7 × 10 −11 cm 3 (STP)cm·cm −2 ·s −1 ·Pa −1 at 0.2 MPa and 35 °C without the loss of N 2 /CH 4 permselectivity, which exceeded the 2008 Robeson upper bound.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Wang Boxuan,Bao Qiang,Chen Zhirui,Qiao Xue,Hu Yunfeng,Zhang Jian,Liang Dan,Sun Penglai,Xia Haiyue,Wang Xiangyang
Zeolite RHO, a microporous zeolite, has the great possibility for N 2 /CH 4 separation by regulating the size of the eight-membered ring window on the RHO framework. In this work, the ability of ion-exchanged RHO zeolites for N 2 /CH 4 separation is investigated, and a highly nitrogen selectivity adsorbents are developed. RHO samples were prepared by hydrothermal synthesis. Alkali metal cations (Na + , K + , Cs + ) was used for ion exchange. Adsorption equilibrium isotherms of N 2 and CH 4 were measured at normal temperature and fitted by the Langmuir equation. The adsorbent selection parameters ( S parameters) were calculated based on the working capacity and equilibrium selectivity of N 2 /CH 4 , which are used to comprehensively evaluate the selectivity of N 2 /CH 4 . The results indicate that the cations have effects on the regulation of the eight-membered ring window. In particularly, K-RHO no.2 sample which is obtained by ion exchange of K + cations exhibit the best N 2 /CH 4 separation performance, which is a potential nitrogen selective adsorbent. In addition, the product throughputs of RHO and the commercial adsorbent ETS-4 were compared by common PSA simulation process with essentially the same product purity and recovery. The results show that K-RHO no.2 has 36 % higher product throughput than ETS-4, which can compensate for the problem of low N 2 working capacity of ETS-4 in industrial application.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Feifei Zhang,Kunjie Li,Jian Chen,Xinran Zhang,Kebing Li,Hua Shang,Lei Ma,Wujie Guo,Xinlong Wu,Jiangfeng Yang,Jinping Li
Natural gas purification by economic and low-energy adsorptive separation processes is important. However, as a difficult global problem, N 2 removal from N 2 /CH 4 mixtures is challenging because of their similar physical properties. In this study, the separation of N 2 /CH 4 by Cr-metal–organic frameworks (MOFs) (MIL-100Cr, MIL-101Cr and TYUT-96Cr) with various open Cr site densities was studied. Gas sorption isotherms showed that TYUT-96Cr exhibited the highest N 2 /CH 4 uptake ratio (13.67 at 0.01 bar and 298 K) of the selected Cr-MOFs, which was consistent with the highest density of Cr (III) sites. This material provided the highest CH 4 productivity (0.716 mmol/cm 3 ) per cycle for N 2 removal from a 5:95 N 2 /CH 4 mixture to produce 99.99% pure CH 4 , as shown by the breakthrough experiments. Pressure-swing adsorption simulations indicated that, by a two-bed six-step method, pristine 95% methane was enriched to 98.9% by TYUT-96Cr. The largest CH 4 productivity, high breakthrough selectivity and thermal stability of TYUT-96Cr among the Cr-MOFs, made it a promising adsorbent in trace N 2 removal for practical industrial application.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Caijiao Yu,Yueyao Liang,Xiangyu Guo,Zhihua Qiao,Chongli Zhong
Metal-organic framework (MOF)-mixed matrix membranes (MMMs) have the potential to overcome the trade-off limitations between gas separation performance and large-scale fabrication. However, most conventional MOF MMMs are used for CH 4 /N 2 separation systems, the preparation of MOF-MMMs with high permeance and good selectivity for N 2 /CH 4 separation has rarely been reported. Here in, we propose supported thin MOF-MMMs with abundant open metal sites to preferentially adsorb N 2 and improve the N 2 /CH 4 separation performance. The formation of the selectivity layer with abundant open metal sites was realized through dual-induction mechanism of in-situ Co 2+ ion doping and polydimethylsiloxane (PDMS) solution post-modification. The introduction of Co 2+ ions restricted the coordination of Zn-N and increased the number of open metal sites in the ZIF layer during its formation. The post-treated PDMS solution with weak acid could further induce the formation of open metal sites. Meanwhile, the electron paramagnetic resonance and synchrotron radiation-based XAFS results also confirmed that the number of open metal sites in the separation layer increased gradually with the in-situ Co 2+ ion decoration and PDMS solution post-modification. In addition, the PDMS also could repair the intercrystalline defects of the MOF membranes and reduce their non-selectivity area. Therefore, the synthesized ZIF-8 MMMs showed a high N 2 permeance of 1367 GPU and a moderate N 2 /CH 4 selectivity of up to 6.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Jun Ma,Jiahe Zhang,Ye Yuan,Yunqi Zhou,Shenzhen Cong,Guangyu Xing,Jixiao Wang,Zhi Wang
N 2 /CH 4 separation membranes based on N 2 preferential permeation can effectively reduce the recompression cost of CH 4 gas and show promising application prospects in the field of natural gas purification. However, the performance of N 2 /CH 4 separation membranes still needs to be improved. Here, we report a kind of mixed matrix membranes (MMMs) for N 2 /CH 4 separation via using HOF-21 as nanofiller and 6FDA-DAM polyimide as polymer matrix . In this work, the effects of HOF-21 loading, feed side pressure and temperature based on membrane performance were explored, and finally performance variation of the MMMs with operation time was tested. The incorporated HOF-21 nanoparticles with the most probable pore size of about 3.6 Å can significantly increase the diffusion rate of smaller N 2 molecules and enhance the N 2 /CH 4 diffusivity selectivity of the membrane. In addition, compared with polyimide, HOF-21 exhibits almost the same dynamic adsorption of N 2 and CH 4 , which can weaken the solubility of CH 4 and enhance the N 2 /CH 4 solubility selectivity of the membrane. When feed gas pressure was 0.2 MPa, the optimum membrane performance was achieved at the HOF-21 loading of 7 wt%, with N 2 permeance of 5.13 GPU and N 2 /CH 4 (50/50, vol%) selectivity of 20.52 at 298.15 K. Compared with N 2 permeation and N 2 /CH 4 selectivity of the 6FDA-DAM/PAN membrane, the MMMs increased by 67% and 54%, respectively, possessing potential applications in the field of N 2 removal in CH 4 purification.
研究领域:
材料科学
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化学工程
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天然气净化技术
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
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2025
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IF 3.2
Qian Yi,Jiang Qingqing,Xiang Shimeng,Lu Zhenhao,Xu Xiaowen,Yang Jing,Dai Guoliang,Song Ruifeng,Jiang Ji
Separating CO 2 and N 2 from CH 4 is crucial for energy production and environmental protection. This study showed the rapid synthesis of CHA zeolites with different morphologies using an in situ growth method, without the assistance of organic structure directing agents (OSDA) or fluoride media. The crystallization behavior of CHA zeolites was studied in terms of synthesis gel composition (including water content, silicon and aluminum content, alkalinity and Sr 2+ concentration), synthesis temperature and duration. The results suggested that pure phase CHA zeolite nano-aggregates could be synthesized with broad precursor conditions at 150 °C for only 4 h. Then, K-CHA zeolite was ion-exchanged to Na-CHA and Ca-CHA and the adsorption properties of CHA zeolites with different morphologies and ions were studied. The results suggested that Na-CHA exhibited highest CH 4 , CO 2 and N 2 adsorption capacity and showed higher ideal selectivity for N 2 /H 2 ; Although Ca-CHA zeolites exhibited relative lower CO 2 and CH 4 adsorption capacity, it exhibited the highest ideal selectivity for CO 2 /CH 4 ; Simultaneously, K-CHA zeolite exhibited high CH 4 adsorption capacity and high adsorption separation ability of CH 4 /N 2 . Furthermore, breakthrough experiments have confirmed the practical feasibility of separating CO 2 from CH 4 .
研究领域:
材料科学
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化学工程
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吸附与分离
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分子筛合成
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气体分离
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）