Browsing by Author "Etxeberría-Benavides, Miren"
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Item High selectivity ZIF-93 hollow fiber membranes for gas separation(2015-07-18) Cacho-Bailo, Fernando; Caro, Guillermo; Etxeberría-Benavides, Miren; Karvan, Oʇuz; Téllez, Carlos; Coronas, Joaquín; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationZeolitic imidazolate framework-93 (ZIF-93) continuous membranes were synthesized on the inner side of P84 co-polyimide hollow fiber supports by microfluidics. MOFs and polymers showed high compatibility and the membrane exhibited H2-CH4 and CO2-CH4 separation selectivities of 97 (100 °C) and 17 (35 °C), respectively.Item Metal-organic framework membranes on the inner-side of a polymeric hollow fiber by microfluidic synthesis(2015-02-05) Cacho-Bailo, Fernando; Catalán-Aguirre, Silvia; Etxeberría-Benavides, Miren; Karvan, Oğuz; Sebastian, Victor; Téllez, Carlos; Coronas, Joaquín; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationPolymeric hollow fiber membranes represent a high degree of process intensification closer to scaling-up. Metal-organic framework ZIF-7 and ZIF-8 continuous membranes were synthesized on the inner surface of a 520μm outer diameter polysulfone hollow fiber using microfluidics. This provided a constant reactant concentration along the membrane for growing homogeneous, continuous and thin layers of ZIF-7 (2.4μm) and ZIF-8 (3.6μm) with good adherence. The high quality of the membranes and the zeolite-like sodalite porous structure of both MOFs with pore apertures of 0.30-0.34nm allowed operation at high temperature (150°C) and pressure (4bar). High separation factors in CO2 and H2 containing mixtures were achieved.Item MOF-polymer enhanced compatibility: Post-annealed zeolite imidazolate framework membranes inside polyimide hollow fibers(2016) Cacho-Bailo, Fernando; Caro, Guillermo; Etxeberría-Benavides, Miren; Karvan, Oʇuz; Téllez, Carlos; Coronas, Joaquín; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationThermal annealing, a commonly used procedure for improving the performance of polymeric membranes, is in this work exploited in the presence of a metal-organic framework (MOF) supported layer. MOFs and polymers are materials with a common organic character, suggesting an enhanced affinity between them when used together in membrane separation. Zeolite-like imidazolate frameworks (ZIFs) ZIF-8 and ZIF-93 with sod and rho structures and pore apertures of 0.34 and 0.36 nm, respectively, have been grown inside 356 μm OD co-polyimide P84 hollow fibers by microfluidics, leading to continuous supported membranes. When these membranes were thermally in situ annealed below the glass transition temperature, while monitoring both H2 and CH4 permeances, the MOF-polymer adhesion was enhanced. Thus the gas separation selectivity increased without any significant reduction in the gas permeance, and H2/CH4 and CO2/CH4 maximum selectivities of 103 and 18 (ZIF-8) and 101 and 20 (ZIF-93) were respectively measured. The good compatibility between MOF and polymer made improvements possible in the annealing of the membrane once it was prepared. If the annealing of the polymer was carried out before the MOF synthesis, the polymer chain rearrangement and surface smoothing prevented an optimum MOF-polymer interaction and the separation performance worsened. These results proved the compatibility between both materials and their synergistic contribution to gas selective transport.Item On the molecular mechanisms for the H2/CO2 separation performance of zeolite imidazolate framework two-layered membranes(2017-07-01) Cacho-Bailo, Fernando; Matito-Martos, Ismael; Perez-Carbajo, Julio; Etxeberría-Benavides, Miren; Karvan, Oğuz; Sebastián, Víctor; Calero, Sofía; Téllez, Carlos; Coronas, Joaquín; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSDouble-layered zeolitic imidazolate framework (ZIF) membranes were fabricated inside polyimide P84 hollow fibers by a step-synthesis conducted by microfluidic technology and applied to pre-combustion gas separation. Our hypothesis, based on the information provided by a combination of molecular simulation and experiments, is that a CO2 adsorption reduction on the surface of the ZIF-9 would enhance the molecular sieving effect of this ZIF-9 layer and therefore the selectivity in the H-2/CO2 mixture separation of the entire membrane. This reduction would be achieved by means of a less-CO2-adsorptive methylimidazolate-based ZIF-67 or ZIF-8 layer coating the ZIF-9. ZIF-8/ZIF-9 and ZIF-67/ZIF-9 double-layered membranes were prepared and characterized by XRD, FTIR, SEM, FIB, TEM and EDS. This unprecedented strategy led to a H-2/CO2 separation selectivity of 9.6 together with a 250 GPU H-2 permeance at 150 degrees C, showing a significant improvement with respect to the pure ZIF-9 membrane. Double-layered membranes also showed higher apparent CO2 activation energies than single-layered membranes, attributable to a diminished adsorption.Item Polyamide/MOF bilayered thin film composite hollow fiber membranes with tuned MOF thickness for water nanofiltration(2020-04-01) Echaide-Górriz, Carlos; Zapata, José A.; Etxeberría-Benavides, Miren; Téllez, Carlos; Coronas, Joaquín; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSA bilayered polyamide-MOF membrane was synthesized on the inner surface of a hollow fiber support (200/350 mm ID/OD). The continuous MOF layer was prepared by liquid phase crystallization, and after that a polyamide layer was formed by interfacial polymerization on the top of the MOF. Firstly, the influence of time in the crystal growth of the MOF layer (from 15 to 120 min) was studied. The main characteristics of such MOF layer were tested (gas permeance and selectivity, and layer thickness measurements by SEM) to decide which of them were the optimum to support the polyamide thin film. The final bilayered membranes were characterized by SEM imaging and XPS and their performance was established in the nanofiltration of a solution of sunset yellow (450 Da) in water. Both permeance and selectivity were improved compared to a conventional TFC membrane (without the MOF layer): water permeance from 0.06 ± 0.01 to 0.24 ± 0.09 L·m−2·h−1·bar−1, and dye rejection from 88 ± 2 to 98 ± 1%).Item Pre-combustion gas separation by ZIF-8-polybenzimidazole mixed matrix membranes in the form of hollow fibres—long-term experimental study(2021-09-01) Perea-Cachero, Adelaida; Etxeberría-Benavides, Miren; David, Oana; Deacon, Adam; Johnson, Timothy; Malankowska, Magdalena; Téllez, Carlos; Coronas, Joaquín; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSPolybenzimidazole (PBI) is a promising and suitable membrane polymer for the separation of the H2/CO2 pre-combustion gas mixture due to its high performance in terms of chemical and thermal stability and intrinsic H2/CO2 selectivity. However, there is a lack of long-term separation studies with this polymer, particularly when it is conformed as hollow fibre membrane. This work reports the continuous measurement of the H2/CO2 separation properties of PBI hollow fibres, prepared as mixed matrix membranes with metal-organic framework (MOF) ZIF-8 as filler. To enhance the scope of the experimental approach, ZIF-8 was synthesized from the transformation of ZIF-L upon up-scaling the MOF synthesis into a 1 kg batch. The effects of membrane healing with poly(dimethylsiloxane), to avoid cracks and non-selective gaps, and operation conditions (use of sweep gas or not) were also examined at 200°C during approximately 51 days. In these conditions, for all the membrane samples studied, the H2 permeance was in the 22–47 GPU range corresponding to 22–32 H2/CO2 selectivity values. Finally, this work continues our previous report on this type of application (Etxeberria-Benavides et al. 2020 Sep. Purif. Technol.237, 116347 (doi:10.1016/j.seppur.2019.116347)) with important novelties dealing with the use of ZIF-8 for the mixed matrix membrane coming from a green methodology, the long-term gas separation testing for more than 50 days and the study on the membrane operation under more realistic conditions (e.g. without the use of sweep gas).Item Sequential amine functionalization inducing structural transition in aldehyde-containing zeolitic imidazolate framework: application to gas separation membranes: application to gas separation membranes(2017) Cacho-Bailo, Fernando; Etxeberría-Benavides, Miren; Karvan, Oğuz; Téllez, Carlos; Coronas, Joaquín; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSA modification in the gas separation performance of zeolitic imidazolate framework (ZIF)-supported hollow fiber (HF) membranes by means of an imine-condensation functionalization reaction carried out by microfluidics is reported. The accommodation of voluminous amine molecules in the SIM-1, Zn(4-methyl-5-imidazolecarboxaldehyde)2, also known as ZIF-94, sod structure during the functionalization reaction caused the ZIF atoms to be rearranged in a less dense rho structure, with a wider pore diameter and a diminished CO2 affinity. These changes had effects on the membrane performance, resulting in an enhanced CO2 permeance while maintaining a good permeance–selectivity balance. ZIF aldehyde-containing SIM-1 membranes were earlier prepared on the inner side of polymeric P84® HF using a microfluidic approach. The SIM-1 membranes displayed very interesting results in the separation of gas mixtures of great relevance to the natural gas field. High selectivities in the separation of He/CH4 (160), H2/CH4 (136) and CO2/CH4 (38) mixtures were achieved, and these are the first SIM-1 membranes with such a high separation performance to the best of our knowledge. These SIM-1 membranes were in situ stepwise functionalized with long-chain amine solutions, namely, hexyl- and nonylamine. Microfluidics allowed the easy sequential implementation of this post-reaction step in the membrane fabrication procedure. An imine-condensation reaction took place between the aldehyde groups in the 4-methyl-5-imidazolecarboxaldehyde ligand forming SIM-1 and the corresponding amines. The extent of the reaction was analyzed by FTIR, TGA and XRD, together with the changes in the textural properties and the adsorption capacities.Item Structural Contraction of Zeolitic Imidazolate Frameworks: Membrane Application on Porous Metallic Hollow Fibers for Gas Separation(2017-06-21) Cacho-Bailo, Fernando; Etxeberría-Benavides, Miren; David, Oana; Téllez, Carlos; Coronas, Joaquín; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSPositive thermal expansion coefficients (TECs) of 52 × 10-6 and 35 × 10-6 K-1 were experimentally calculated in the -116 to 250 °C range for the III-phases of zeolitic imidazolate frameworks (ZIF) ZIF-9(Co) and ZIF-7(Zn), respectively, by means of the unit cell dimensions and volume of the materials in the monoclinic crystal system calculated from the XRD patterns. The unit cell dimensions and volume showed a significant expansion phenomenon as the temperature increased, by as much as 5.5% for ZIF-9-III in the studied range. To exploit the advantages of such thermal behavior, a new approach to the fabrication of ZIF-9-III membranes on thin, flexible, and highly porous nickel hollow fiber (Ni HF) supports by a versatile and easy-controllable microfluidic setup is herein reported. These Ni HF supports result from the sintering of 25-μm Ni particles and display very positive mechanical properties and bending resistance. As compared to the traditional polymer-based HF membranes, the ZIF metal-supported membrane exhibited good durability and robustness throughout its operation in a wide temperature range and after heating and cooling cycles. These benefits derive from (1) the pore-plugging membrane configuration resulting from the high porosity of the support and (2) the similarity between the TECs of the ZIF and the metallic support, both positive, which enhances their mutual compatibility. An increase in the H2/CO2 separation selectivity at low temperatures (as high as 22.2 at -10 °C, along with 102 GPU permeance of H2) was achieved, in agreement with the structural variations observed in the ZIF material.