SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xue-Jie Zhang,Wen-Cui Li,Ya-Qi Ba,Gang Li,Guang-Ping Hao,An-Hui Lu
The uptake of hydrogen (H 2 ) from natural gas pipelines (CH 4 ) through membrane separation technology is an efficient avenue of obtaining H 2 resources. Carbon membranes have the potential to be an attractive option for energy-efficient gas separations in the next generation of membranes due to their precise molecular discrimination ability and easy scalability. Here, we report a carbon membrane composed of a mesoporous substrate, seed layer and sieving layer, achieving a one-step uptake with 55.3 × 10 -9 mol·m −2 ·s −1 Pa −1 permeance and a separation factor for H 2 /CH 4 of 359.1 by feeding hydrogen (20 vol%). As revealed by the kinetic diffusion experiment, H 2 is transported in mesoporous substrate via Knudsen flow, differing from the transition flow taken by CH 4 , thus H 2 diffusion rates exceed CH 4 by an order of magnitude, which substantially increased H 2 purity from 20 vol% to higher purity as gas mixtures passed through the substrate. Then, the H 2 passed through the seed layer and sieving layer, resulting in a final H 2 purity of ∼ 99 vol%, a sharp increase from the initial low concentration. This carbon membrane integrates three functions of capture, pre-separation and purification into one material and provides a new solution for the uptake of H 2 from CH 4 .
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Wenji Zheng,Yuehu Guo,Ziheng Li,Xuehua Ruan,Xiaobin Jiang,Tiantian Li,Xiangcun Li,Yan Dai,Gaohong He
Polymer-supported MOFs membranes with high separation performances show great potentials in industrial purification of H 2 . The key to growing defect-free and adherent MOFs layers on polymer substrates is the abundant and uniformly distributed nucleation sites on the surface of polymer substrates. Therefore, in this work, a mixed-matrix polyacrylonitrile (PAN) substrate with ZIF-8-rich seed layer (ZS-PAN) was constructed by gravity induced deposition and gradient distribution of ZIF-8 before phase inversion, then under the assistance of Tannic acid (TA), the dense and defect-free ZIF-8 membrane on flexible polymer substrate was fabricated followed by the secondary growth of ZIF-8. The EDS and SEM results of the membrane cross-section confirm the gradient distribution of ZIF-8 seeds, and the resultant membranes are defect-free. The H 2 permeance of TA-ZIF-8/ZS-PAN membrane is 953.66 GPU, and the H 2 /CO 2 selectivity is 12.09, which is 80.17 % higher than that of ZIF-8/ZS-PAN membrane without TA, exceeding the Robeson upper bound in 2008. This improved H 2 separation performance is derived from the following reasons. First, gravity-induced ZIF-8 seed deposition constructs a ZIF-8-rich seed layer on the mixed-matrix polymer substrate, which increases the nucleation sites. Second, the introduction of TA during the secondary growth process further increases the nucleation sites by hydroxyl-chelated zinc ions, both of which contribute to the dense ZIF-8 membrane. At the same time, the hydroxyl group in TA is CO 2 -philic, which can delay CO 2 permeation and improve the H 2 /CO 2 separation performance by physically adsorbing CO 2 . The proposed mixed-matrix substrate by gravity induced deposition of MOFs provides a novel strategy for constructing defect-free and flexible MOFs membrane.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Xilu Hong,Zong Lu,Yali Zhao,Luxi Lyu,Li Ding,Yanying Wei,Haihui Wang
As one of the green, renewable, and clean energy resources, hydrogen is widely developed and utilized throughout the world. Highly efficient membrane separation for hydrogen production is required to give promising gas permeance with enough H 2 selectivity. The membranes are desired to be produced in large-scale, fast and facile methods. Here we report for the first time a kind of freestanding MXene-ZIF-8 dual-layered membrane for hydrogen separation. Fast synthesis of such membranes is realized by combining electrophoretic deposition (EPD) and fast current-driven synthesis (FCDS), achieving the assemble of MXene layer and growth of ZIF-8 layer, respectively, overcoming the traditional time-consuming vacuum filtration methods and solvothermal synthesis . The MXene-ZIF-8 dual-layered membrane prepared within 20 min exhibits significantly improved gas separation performance, whose H 2 /CO 2 selectivity increases from 44 for the pristine MXene membrane to 77 with H 2 permeance of 5.97 × 10 −8 mol m −2 s −1 Pa −1 . This concept of structure design of membrane can also be extended to other dual-layered membranes, including various 2D nanosheet layers combined with different MOF layers.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Hanhan Chen,Xiaobin Wang,Yi Liu,Tengfei Yang,Naitao Yang,Bo Meng,Xiaoyao Tan,Shaomin Liu
Despite many methods available to synthesize MOF membrane, the cost-effective synthesis with high reproducibility and scalability is still a challenge. We present here a homologous support-induced approach for the growth of ZIF membrane supported on the dual-layer ZnO–Al2O3 hollow fibers, which has the potential for applications at larger scales. The developed unique dual-layer hollow fibers consisting of a thin outer ZnO layer firmly attached onto an inner porous alumina substrate were realized through one-step co-extrusion/sintering technique. During the MOF membrane synthesis, ZnO can be used not only as the support, but also as the nucleation sites and growth centers for the ZIF-8 membrane formation. More importantly, ZnO can act as a transitional bridge to direct the membrane growth outward along the support and inward embedded into the support, which significantly improving the binding force between the support and MOF, thus bringing in the outstanding membrane stability. Permeation of single gas and separation of binary mixtures revealed that the prepared membranes were free of defects. The resultant ZIF-8 composite membrane exhibits good hydrogen separation performance and excellent reproducibility. This protocol can achieve an easy and large-scale synthesis. In addition to ZIF-8 membrane, ZIF-67 membrane was also successfully synthesized via this method, which may provide some general guidelines for the preparation of other MOF membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2020
·Vol. 15
·期 4
·882-891
·
IF 3.552
Fan Yiyi,Li Jinyong,Wang Saidi,Meng Xiuxia,Jin Yun,Yang Naitao,Meng Bo,Li Jiaquan,Liu Shaomin
Hydrogen fuel has been embraced as a potential long-term solution to the growing demand for clean energy. A membrane-assisted separation is promising in producing high-purity H 2 . Molecular sieving membranes (MSMs) are endowed with high gas selectivity and permeability because their well-defined micropores can facilitate molecular exclusion, diffusion, and adsorption. In this work, MXene nanosheets intercalated with Ni 2+ were assembled to form an MSM supported on Al 2 O 3 hollow fiber via a vacuum-assisted filtration and drying process. The prepared membranes showed excellent H 2 /CO 2 mixture separation performance at room temperature. Separation factor reached 615 with a hydrogen permeance of 8.35 × 10 −8 mol·m −2 ·s −1 ·Pa −1 . Compared with the original Ti 3 C 2 T x /Al 2 O 3 hollow fiber membranes, the permeation of hydrogen through the Ni 2+ -Ti 3 C 2 T x /Al 2 O 3 membrane was considerably increased, stemming from the strong interaction between the negatively charged MXene nanosheets and Ni 2+ . The interlayer spacing of MSMs was tuned by Ni 2+ . During 200-hour testing, the resultant membrane maintained an excellent gas separation without any substantial performance decline. Our results indicate that the Ni 2+ tailored Ti 3 C 2 T x /Al 2 O 3 hollow fiber membranes can inspire promising industrial applications.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2025
·
IF 4.7
Weibo Chen,Feng Ye,Shuanshi Fan,Yanhong Wang,Xuemei Lang,Zijian Zhang,Gang Li
Manipulating pore structures with precisely controlled pore sizes and surface chemistry is essential for fabricating high-quality zeolite membranes. This study aims to improve the performance of SSZ-13 membranes by tuning their pore structures using an occluded organic structure-directing agent (OSDA) through low-temperature hydrocracking. The resulting membranes demonstrated notable improvements in H 2 /CO 2 separation. Permeation tests indicated that the SSZ-13 zeolite membrane achieved a moderate H 2 permeance of 1.04 × 10 −7 mol Pa −1 m −2 s −1 , along with a markedly improved H 2 /CO 2 ideal selectivity of 225 at 150 °C. Both H 2 and CO 2 permeances increased significantly through the membrane with increasing temperatures, suggesting an activated diffusion mechanism for their permeation. The activation energy for H 2 permeation was calculated to be as high as 8.98 kJ mol −1 , suggesting that the membrane has a relatively small mean pore size and minimal defects. CO 2 adsorption and temperature-programmed desorption (TPD) analysis showed a pronounced interaction between CO 2 molecules and the SSZ-13 membrane, likely accounting for the exceptionally low CO 2 permeance observed. These SSZ-13 zeolite membranes demonstrate considerable potential for efficient H 2 /CO 2 separation in practical applications.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Yi Ren,Die He,Tong Wang,Hong Qi
Organosilica membranes with good hydrothermal stability are promising for pre-combustion capture, but the trade-off effect still constrains their gas separation performance. Herein, we prepared hybrid membranes by incorporating ZIF-7 nanoparticles into 1, 2-bis(triethoxysilyl)ethane (BTESE) networks to improve the H 2 /CO 2 permselectivity by the intrinsic properties of nanoparticles. The effect of inorganic fillers was investigated by adjusting the doping content of ZIF-7 nanoparticles. We found that the H 2 permeance of hybrid membranes remained at ∼10 −6 mol·m −2 ·s −1 ·Pa −1 , while the H 2 /CO 2 permselectivity decreased with increasing nanoparticle doping content. The E-ZIF-7-0.4 hybrid membrane showed H 2 permeance of 1.2 × 10 −6 mol·m −2 ·s −1 ·Pa −1 and H 2 /CO 2 permselectivity of 21.7. Our results may offer valuable insights into preparing hybrid membranes with optimal nanoparticle doping content.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Shenghan Ji,Ziheng Li,Yan Dai,Xiaobin Jiang,Xuehua Ruan,Wenji Zheng,Gaohong He
MOF membrane supported on flexible substrates faces the issues of non-selective defects as well as poor mechanical compatibility. Herein, a “rigid and flexible” MOF/COF molecular sieving membrane is acquired by the in-situ polymerization of COFs among the inter-crystalline and interfacial defects in the MOF membrane. Taking advantage of different osmotic pressures on both sides of MOF membrane during the counter-diffusion process, the COFs monomers diffuse from bottom to top to the inter-crystalline and interfacial defects and meet with the catalyst for further polymerization and crystallization, thus repairing non-selective defects of the MOF membrane. In the MOF/COF membrane, COFs exhibit a strong adsorption affinity for CO 2 , which can slow down CO 2 permeation and enhance H 2 /CO 2 selectivity. Meanwhile, the in-situ polymerization of COFs primarily occurs at the inter-crystalline defects of MOF membrane and the interface between MOF membrane and polymer substrate, without forming a resistance layer on MOF membrane surface, which is demonstrated by the SEM and AFM results. Additionally, the counter-diffusion growth of COFs allows for the connection between the organic substrate and the inorganic MOFs layer through COFs, thereby improving the mechanical flexibility of MOF membrane confirmed by the mechanical properties. Besides, through regulating the polymerization process of TpPa-1 including time and monomer concentration, the H 2 /CO 2 separation of ZIF-67/TpPa-1 membrane can be tuned precisely. Therefore, the ZIF-67/TpPa-1–0.90 membrane at a polymerization time of 24 h presents H 2 permeance of 1114 GPU and H 2 /CO 2 selectivity of 17.52, an increase of 178.1 % compared to the pure ZIF-67 membrane, which is far beyond the 2008 upper bound and approaching the up-to-date data line. Together with the additional good mechanical properties, stability and universality, the proposed “rigid and flexible” MOF/COF molecular sieving membrane is promising in H 2 /CO 2 separation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yuxuan Feng,Shuhui Chen,Kaisheng Hua,Hui Li,Dong Jiang,Lujie Sheng,Dan Zhao,Jizhong Ren
Thermally rearranged(TR) polymers are usually prepared at an insert atmosphere and display high gas permeability, but their low gas selectivity results in high energy consumption. Thermal oxidation is an effective method to enhance the gas selectivity of microporous polymers. In this work, the effect of oxygen in the purge environment on imide-to-benzoxazole conversion and membrane structures was investigated. 1% oxygen content of the purge environment could restrain imide-to-benzoxazole conversion of 6FDA-DETDA/bisAPAF hydroxyl block polyimide(bHPI) membranes effectively, and oxygen induced the oxygen bridge formation, improving the gas selectivities of the resulting thermal-oxidative membranes with the increased oxygen content. Thermal-oxidative PBOCI membranes (TO-PBOCI) based on block poly(benzoxazole-co-imide)(PBOCI) precursor membranes were prepared to enhance gas separation performance of microporous polymers. The stable polybenzoxazole structures and microphase separation of polybenzoxazole blocks maintained membrane structures and the gas transport channels in the thermal-oxidative process at high temperature. Significantly, the remaining hydroxyl groups in PBOCI precursor membranes were beneficial for oxygen bridge formations of TO-PBOCI membranes, enhancing H 2 /CH 4 selectivity. As a result, the TO-PBOCI membranes treated at a high temperature kept high H 2 permeability and H 2 /CH 4 selectivity, surpassing the 2008 Robeson upper bound. The study about TO-PBOCI membranes promotes a better understanding of the polymeric materials and process development of microporous polymer membranes for hydrogen separation applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Xiuxiu Ren,Fukang Shi,Meng Guo,Jing Zhong,Rong Xu,Zheng Yao,Dongliang Jin,Ting Qi,Liang Zhou
Two-dimensional (2D) molybdenum disulfide (MoS2) with a unique action on H2 was incorporated into 1,2-bis(triethoxysilyl)ethane (BTESE)-derived bridged microporous organosilica networks to form a composite membrane for H2 separation by a sol–gel method. Due to their opposite ζ-potentials, a continuous surface without lamellar boundary defects was formed between BTESE sols derived by the hydrolysis–polymerization reaction and MoS2 nanosheets. When the MoS2 content increased in BTESE networks, the H2 permeance showed an overall increasing trend in the range of 1.85–2.89 × 10–7 mol·m–2 s–1 Pa–1 (552–864 GPU), which was higher than that of pristine BTESE membrane with the H2 permeance of 491 GPU. In addition, optimized MoS2/BTESE membranes showed a much higher H2/N2 permselectivity of 129 than that of the pristine BTESE membrane of 17 at 100 °C. The synergistic effect of BTESE and MoS2 nanosheets plays an important role. Through adsorption isotherm test and diffusivity as well as energy calculation, BTESE networks became denser by nonporous MoS2 addition that prevented N2 from passing, while H2 was promoted with excellent adsorption on charged edges of MoS2, resulting in improved H2 separation performance both in permeance and selectivity. This provides an attractive mechanism for hydrogen separation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Tao Zhou,Mingyu Zhu,Yong Dai,Lingjie Chen,Junyan Xie,Yuting Zhang,Xuerui Wang,Xuehong Gu
STT zeolite membrane with seven-membered rings (7 MR) and nine-membered rings (9 MR) is an ideal alternative for the separation of hydrogen (H 2 ) and methane (CH 4 ). However, the successful synthesis is only possible in rotation conditions, which is difficult to achieve at an industrial scale. Herein we developed a static synthesis approach to prepare high-quality STT zeolite membranes. The precursor transformed in-situ from a liquid state to a semi-solid state to efficiently suppress the nucleation in the bulk gel. This did not affect the growth of the seed layer to form a continuous membrane. The water content was modulated between y = 44 and y = 124 in the molar composition of 1 SiO 2 : 0.2 TMAdaOH: y H 2 O. The precursor could be re-used one more time to reduce the total amount of chemical waste. The optimal H 2 permeance and H 2 /CH 4 mixture selectivity was up to 6.1 × 10 −8 mol m −2 s −1 Pa −1 and 115 at atm pressure. The H 2 permeation flux monotonically increased to 2.0 Nm 3 m −2 h −1 under feed pressure up to 2.1 MPa. This paves the way for zeolite membranes to high-pressure H 2 separation in practical applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 67
·54757-54761
·
IF 3.84
Songjie Fan,Shan Wu,Jianhua Liu,Dan Liu
The synthesis conditions of MIL-120 membranes supported by a-Al2O3 hollow ceramic fibers (HCFs) were studied systemically. The continuous and compact MIL-120 membranes were successfully synthesised by secondary growth with in situ seeding step. The MIL-120 membrane shows the separation factors of H2–CO2, H2–CH4 and H2–N2 are 9.4, 7.9, and 7.3 respectively at 293 K and 1 bar with H2 permeance of 3.5 × 10−7 mol m−2 s−1 Pa−1 as well as high thermal stability.
研究领域:
材料科学
·
化学工程
✓ 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）