Browsing by Keyword "Physical and Theoretical Chemistry"
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Item Attrition-resistant membranes for fluidized-bed membrane reactors: Double-skin membranes: Double-skin membranes(2018-10-01) Arratibel, Alba; Medrano, Jose Antonio; Melendez, Jon; Pacheco Tanaka, D. Alfredo; van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationPd-Ag supported membranes have been prepared by coating a ceramic interdiffusion barrier onto a Hastelloy X (0.2 µm media grade) porous support followed by deposition of the hydrogen selective Pd-Ag (4–5 µm) layer by electroless plating. To one of the membranes an additional porous Al2O3-YSZ layer (protective layer with 50 wt% of YSZ) was deposited by dip-coating followed by calcination at 550 °C on top of the Pd-Ag layer, and this membrane is referred to as a double-skin membrane. Both membranes were integrated at the same time in a single reactor in order to assess and compare the performance of both membranes under identical conditions. The membranes have first been tested in an empty reactor with pure gases (H2 and N2) and afterwards in the presence of a catalyst (rhodium onto promoted alumina) fluidized in the bubbling regime. The membranes immersed in the bubbling bed were tested at 400 °C and 500 °C for 115 and 500 h, respectively. The effect of the protective layer on the permeation properties and stability of the membranes were studied. The double-skinned membraned showed a H2 permeance of 1.55·10−6 mol m−2 s−1 Pa−1 at 500 °C and 4 bar of pressure difference with an ideal perm-selectivity virtually infinite before incorporation of particles. This selectivity did not decay during the long term test under fluidization with catalyst particles.Item Development of Pd-based double-skinned membranes for hydrogen production in fluidized bed membrane reactors(2018-03-15) Arratibel, Alba; Pacheco Tanaka, Alfredo; Laso, Iker; van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThis paper reports the preparation and performance characterization of new PdAg supported membranes with a porous protecting layer to protect the membrane surface from particles in a fluidized bed membrane reactor. Supported membranes with a selective layer of 1 µm and a protective layer have been prepared. Outstanding H2 permeance (5·10−6 mol m−2 s−1 Pa−1) and H2/N2 perm-selectivity (over 25,000) were measured at 400 °C and 1 bar of pressure difference. One membrane has been tested for more than 750 h in the presence of fluidized glass beads showing a decay in the perm-selectivity to approximately 5000, mainly due to sealing leakage. However, the protective layer was removed during this long-term test. Another membrane has been tested for more than 2000 h in a fluidized bed membrane reactor with a Rh reforming catalyst supported on promoted alumina in the bubbling fluidization regime. During tests with binary mixtures mass transfer limitations toward the membrane were observed due to large H2 permeance of the membranes.Item Effect of the catalyst system on the reactivity of a polyurethane resin system for RTM manufacturing of structural composites(2022-03) Echeverria-Altuna, Oihane; Ollo, Olatz; Calvo-Correas, Tamara; Harismendy, Isabel; Eceiza, Arantxa; Tecnalia Research & Innovation; POLIMEROSThe high versatility of polyurethanes (PU’s) is encouraging the development of new formulations for new appli cations, like their use as a matrix for structural composites. PU’s based technology offers some advantages, such as fatigue resistance and fast curing cycles. However, their high reactivity hinders some manufacturing processes like Resin Transfer Moulding (RTM). This work aimed to achieve a PU resin (PUR) formulation with the required latency and reactivity for the RTM. For this purpose, different catalytic systems based on an epoxide and LiCl were investigated. The reactivity of the systems was evaluated through Differential Scanning Calorimetry (DSC) and rheology tests, and the curing reaction and viscosity were modelled. Furthermore, the RTM process of a representative composite part was simulated. Results demon strated the processability improvements when the LiCl was incorporated into the isocyanate component of the formulation combined with a monool or a diol. It was observed that these combinations contribute to the encapsulation of the LiCl between the as formed urethane groups by hydrogen bonding, providing the desired latency and acting as a delayed action catalyst. Once the reaction started and the encapsulation was deactivated, an alkoxide was formed to act as a catalyst. En capsulation was more effective with the diol, providing a higher latency.Item Effects of Human and Porcine Adipose Extracellular Matrices Decellularized by Enzymatic or Chemical Methods on Macrophage Polarization and Immunocompetence(2021-04-08) Cicuéndez, Mónica; Casarrubios, Laura; Feito, María José; Madarieta, Iratxe; Garcia-Urkia, Nerea; Murua, Olatz; Olalde, Beatriz; Briz, Nerea; Diez-Orejas, Rosalía; Portolés, María Teresa; Biomateriales; SGThe decellularized extracellular matrix (ECM) obtained from human and porcine adipose tissue (AT) is currently used to prepare regenerative medicine bio-scaffolds. However, the influence of these natural biomaterials on host immune response is not yet deeply understood. Since macrophages play a key role in the inflammation/healing processes due to their high functional plasticity between M1 and M2 phenotypes, the evaluation of their response to decellularized ECM is mandatory. It is also necessary to analyze the immunocompetence of macrophages after contact with decellularized ECM materials to assess their functional role in a possible infection scenario. In this work, we studied the effect of four decellularized adipose matrices (DAMs) obtained from human and porcine AT by enzymatic or chemical methods on macrophage phenotypes and fungal phagocytosis. First, a thorough biochemical characterization of these biomaterials by quantification of remnant DNA, lipids, and proteins was performed, thus indicating the efficiency and reliability of both methods. The proteomic analysis evidenced that some proteins are differentially preserved depending on both the AT origin and the decellularization method employed. After exposure to the four DAMs, specific markers of M1 proinflammatory and M2 anti-inflammatory macrophages were analyzed. Porcine DAMs favor the M2 phenotype, independently of the decellularization method employed. Finally, a sensitive fungal phagocytosis assay allowed us to relate the macrophage phagocytosis capability with specific proteins differentially preserved in certain DAMs. The results obtained in this study highlight the close relationship between the ECM biochemical composition and the macrophage’s functional role.Item Enhancing Osteoconduction of PLLA-Based Nanocomposite Scaffolds for Bone Regeneration Using Different Biomimetic Signals to MSCs(2012-02) Ciapetti, Gabriela; Granchi, Donatella; Devescovi, Valentina; Baglio, Serena R.; Leonardi, Elisa; Martini, Desirèe; Jurado, Maria Jesus; Olalde, Beatriz; Armentano, Ilaria; Kenny, Josè M.; Walboomers, Frank X.; Alava, J.I.; Baldini, Nicola; Tecnalia Research & Innovation; BiomaterialesIn bone engineering, the adhesion, proliferation and differentiation of mesenchymal stromal cells rely on signaling from chemico-physical structure of the substrate, therefore prompting the design of mimetic “extracellular matrix”-like scaffolds. In this study, three-dimensional porous poly-L-lactic acid (PLLA)-based scaffolds have been mixed with different components, including single walled carbon nanotubes (CNT), micro-hydroxyapatite particles (HA), and BMP2, and treated with plasma (PT), to obtain four different nanocomposites: PLLA + CNT, PLLA + CNTHA, PLLA + CNT + HA + BMP2 and PLLA + CNT + HA + PT. Adult bone marrow mesenchymal stromal cells (MSCs) were derived from the femur of orthopaedic patients, seeded on the scaffolds and cultured under osteogenic induction up to differentiation and mineralization. The release of specific metabolites and temporal gene expression profiles of marrow-derived osteoprogenitors were analyzed at definite time points, relevant to in vitro culture as well asin vivo differentiation. As a result, the role of the different biomimetic components added to the PLLA matrix was deciphered, with BMP2-added scaffolds showing the highest biomimetic activity on cells differentiating to mature osteoblasts. The modification of a polymeric scaffold with reinforcing components which also work as biomimetic cues for cells can effectively direct osteoprogenitor cells differentiation, so as to shorten the time required for mineralization.Item Fluidized Bed Membrane Reactors for Ultra Pure H2 Production - A Step forward towards Commercialization(2016-03-19) Helmi, Arash; Fernandez, Ekain; Melendez, Jon; Pacheco Tanaka, David A.; Gallucci, Fausto; van Sint Annaland, Martin; TECNOLOGÍAS DE HIDRÓGENO; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSIn this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm3/h of ultra-pure H2 was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H2 partial pressure differences. The membranes showed very high H2 fluxes (3.89E 6 mol m 2 Pa 1 s 1 at 400 C and 1 atm pressure difference) with a H2/N2 ideal perm-selectivity (up to 21,000 when integrating five membranes in the module) beyond the DOE 2015 targets. Monitoring the performance of the membranes and the reactor confirmed a very stable performance of the unit for continuous high temperature water gas shift under bubbling fluidization conditions. Several experiments were carried out at different temperatures, pressures and various inlet compositions to determine the optimum operating window for the reactor. The obtained results showed high hydrogen recovery factors, and very low CO concentrations at the permeate side (in average <10 ppm), so that the produced hydrogen can be directly fed to a low temperature PEM fuel cell.Item High performance mixed matrix membranes (MMMs) composed of ZIF-94 filler and 6FDA-DAM polymer(2018-03-15) Etxeberria-Benavides, Miren; David, Oana; Johnson, Timothy; Łozińska, Magdalena M.; Orsi, Angelica; Wright, Paul A.; Mastel, Stefan; Hillenbrand, Rainer; Kapteijn, Freek; Gascon, Jorge; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSCarbon capture and storage (CCS) using membranes for the separation of CO2 holds great promise for the reduction of atmospheric CO2 emissions from fuel combustion and industrial processes. Among the different process outlines, post-combustion CO2 capture could be easily implemented in existing power plants. However, for this technology to become viable, new membrane materials have to be developed. In this article we present the development of high performance mixed matrix membranes (MMMs) composed of ZIF-94 filler and 6FDADAM polymer matrix. The CO2/N2 separation performance was evaluated by mixed gas tests (15CO2:85N2) at 25 °C and 1–4 bar transmembrane pressure difference. The CO2 membrane permeability was increased by the addition of the ZIF-94 particles, maintaining a constant CO2/N2 selectivity of ~22. The largest increase in CO2 permeability of ~ 200% was observed for 40 wt% ZIF-94 loading, reaching the highest permeability (2310 Barrer) at similar selectivity among 6FDA-DAM MMMs reported in literature. For the first time, the ZIF-94 metal organic framework crystals with particle size smaller than 500 nm were synthesized using nonhazardous solvent (tetrahydrofuran and methanol) instead of dimethylformamide (DMF) in a scalable process. Membranes were characterized by three non-invasive image techniques, i.e. SEM, AFM and nanoscale infrared imaging by scattering-type scanning near-field optical microscopy (s-SNOM). The combination of these techniques demonstrates a very good dispersion and interaction of the filler in the polymer layer, even at very high loadings.Item Highly Active Ni–Fe Based Oxide Oxygen Evolution Reaction Electrocatalysts for Alkaline Anion Exchange Membrane Electrolyser(2022-04-23) Vincent, Immanuel; Lee, Eun-Chong; Kim, Hyung-Man; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENOOxygen evolution reaction (OER) electrocatalysts are pivotal for sustainable hydrogen production through anion exchange membrane electrolysis. Cost-effective transition metals such as nickel and iron-based oxides (Ni–Fe–Ox) have been recognized as viable catalysts for the oxygen evolution process in alkaline media. In this work, we study the electrochemical characterization and stability of the Ni–Fe–Ox to find the suitability for AEM electrolysis. The results indicate that Ni–Fe–Ox has 5 times higher activity than pure Ni. The Ni–Fe–Ox electrodes exhibit an exceptionally high catalytic activity of 22 mA cm−2 at 1.55 V vs. RHE, and a Tafel value as low as 97 dec−1, for OER to occur. These findings imply that OER occurs at similar places along the Ni–Fe–Ox interface and that the Ni—Fe2O3 contact plays a significant role as the OER active site. Furthermore, it is also worth noting that the presence of metallic Ni allows for fast electron transit within the interface, which is necessary for successful electrocatalysis. Aside from the excellent OER performance, the exfoliated Ni–Fe–Ox demonstrated great stability with almost constant potential after 10 h of electrolysis at a current density of 10 mA cm−2. This work confirms Ni–Fe–Ox is a promising, highly efficient and cost-effective OER catalyst for AEM electrolysis.Item Label-free optical biosensing using low-cost electrospun polymeric nanofibers(2020-11-26) Martínez-Pérez, Paula; Ponce-Alcántara, Salvador; Murillo, Nieves; Pérez-Márquez, Ana; Maudes, Jon; Peraile, Inés; González-López, Laura; Gil-García, Matilde; Lorenzo-Lozano, Paloma; García-Rupérez, Jaime; Tecnalia Research & Innovation; PRINTEXPolymeric nanofiber matrices are promising structures to develop biosensing devices due to their easy and affordable large-scale fabrication and their high surface-to-volume ratio. In this work, the suitability of a polyamide 6 nanofiber matrix for the development of a label-free and real-time Fabry–Pérot cavity-based optical biosensor was studied. For such aim, in-flow biofunctionalization of nanofibers with antibodies, bound through a protein A/G layer, and specific biodetection of 10 µg/mL bovine serum albumin (BSA) were carried out. Both processes were successfully monitored via reflectivity measurements in real-time without labels and their reproducibility was demonstrated when different polymeric nanofiber matrices from the same electrospinning batch were employed as transducers. These results demonstrate not only the suitability of correctly biofunctionalized polyamide 6 nanofiber matrices to be employed for real-time and label-free specific biodetection purposes, but also the potential of electrospinning technique to create affordable and easy-to-fabricate at large scale optical transducers with a reproducible performance.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 Morphology and N2 Permeance of Sputtered Pd-Ag Ultra-Thin Film Membranes(2016-02-10) Fernandez, Ekain; Sanchez-Garcia, Jose Angel; Viviente, J.L.; van Sint Annaland, Martin; Gallucci, Fausto; Pacheco Tanaka, David A.; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe influence of the temperature during the growth of Pd-Ag films by PVD magnetron sputtering onto polished silicon wafers was studied in order to avoid the effect of the support roughness on the layer growth. The surfaces of the Pd-Ag membrane films were analyzed by atomic force microscopy (AFM), and the results indicate an increase of the grain size from 120 to 250–270 nm and film surface roughness from 4–5 to 10–12 nm when increasing the temperature from around 360–510 K. After selecting the conditions for obtaining the smallest grain size onto silicon wafer, thin Pd-Ag (0.5–2-µm thick) films were deposited onto different types of porous supports to study the influence of the porous support, layer thickness and target power on the selective layer microstructure and membrane properties. The Pd-Ag layers deposited onto ZrO2 3-nm top layer supports (smallest pore size among all tested) present high N2 permeance in the order of 10−6 mol•m−2•s−1•Pa−1 at room temperature.Item New strategy for the optimal design and manufacture of high performance milling heads(2011) Bustillo, A.; Plaza, L.M.; Rodriguez, M.; Tecnalia Research & InnovationHigh-performance mechanical-transmission heads are one of the most complex, costly and problematic parts of a milling machine, owing to the large amount of piping required for transporting fluids and to the high level of mechanical performance that is required from them. This study proposes a strategy for optimising the design and manufacture of head bodies by using aluminium alloys and by integrating tubular stainless steel inserts in the casting of the head. These tubular inserts that are integrated into the aluminium mass are an alternative to cooling conduits currently made by machine drilling. As demonstrated in the experimental validation of the first prototype, the new method has created a design that retains the same mechanical performance, increases its reliability and reduces the weight of the milling machine’s moving parts.Item Recent Advances in Pd-Based Membranes for Membrane Reactors(2017-01-01) Arratibel Plazaola, Alba; Pacheco Tanaka, David A.; Van Sint Annaland, Martin; Gallucci, Fausto; Tecnalia Research & Innovation; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSPalladium-based membranes for hydrogen separation have been studied by several research groups during the last 40 years. Much effort has been dedicated to improving the hydrogen flux of these membranes employing different alloys, supports, deposition/production techniques, etc. High flux and cheap membranes, yet stable at different operating conditions are required for their exploitation at industrial scale. The integration of membranes in multifunctional reactors (membrane reactors) poses additional demands on the membranes as interactions at different levels between the catalyst and the membrane surface can occur. Particularly, when employing the membranes in fluidized bed reactors, the selective layer should be resistant to or protected against erosion. In this review we will also describe a novel kind of membranes, the pore-filled type membranes prepared by Pacheco Tanaka and coworkers that represent a possible solution to integrate thin selective membranes into membrane reactors while protecting the selective layer. This work is focused on recent advances on metallic supports, materials used as an intermetallic diffusion layer when metallic supports are used and the most recent advances on Pd-based composite membranes. Particular attention is paid to improvements on sulfur resistance of Pd based membranes, resistance to hydrogen embrittlement and stability at high temperature.Item Use of a reforming catalyst for hydrogen production in the carbonization process of torrefied biomass(2020-11-10) Lopez-Urionabarrenechea, Alexander; Acha, Esther; Adrados, Aitziber; Solar, Jon; Caballero, Blanca María; de Marco, Isabel; PROMETALThe utilization of charcoal from woody biomass is an efficient way to reduce CO2 emissions from the metallurgical industry. The main aim of this work is to study the charcoal production process from torrefied biomass. For this purpose, torrefaction (3◦C min−1, 250◦C, 30 min) and carbonization (3◦C min−1, 750◦C, 30 min) experiments of eucalyptus wood were carried out in a 3.5 L tank reactor. In the carbonization experiments, a thermo-catalytic treatment of the vaporized phase was also performed, with the objective of producing less condensates and H2-rich gases. The results show that the torrefaction pre-treatment does not affect the chemical properties of charcoal but significantly improves the performance of the carbonization process, where more than 50 wt% of charcoal is obtained. In addition, the thermal and thermo-catalytic treatment of the vaporized phase during the carbonization of torrefied biomass yields better results than in the case of fresh biomass. When torrefied biomass is used as raw material and the reforming catalyst is employed to treat the vapors and gases, a proportion of 71 vol% of H2 in the gases is achieved, together with very low quantities of condensates (8.0 wt%). This allows designing a carbonization process in which, in addition to charcoal, pure H2 can also be produced.Item Water-Facilitated Electrodeposition of Neodymium in a Phosphonium-Based Ionic Liquid(2019-01-17) Sanchez-Cupido, Laura; Pringle, Jennifer M.; Siriwardana, Amal L.; Unzurrunzaga, Ainhoa; Hilder, Matthias; Forsyth, Maria; Pozo-Gonzalo, Cristina; VALORIZACIÓN DE RESIDUOS; Tecnalia Research & InnovationRare-earth metals are considered critical metals due to their extensive use in energy-related applications such as wind turbines and nickel-metal hybrid batteries found in hybrid electrical vehicles. A key drawback of the current processing methods includes the generation of large amounts of toxic and radioactive waste. Thus the efficient recovery of these valuable metals as well as cleaner processing methods are becoming increasingly important. Here we report on a clean electrochemical route for neodymium (Nd) recovery from [P 6,6,6,14 ][TFSI], trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)amide which is amplified three times by the presence of water, as evidenced by the cathodic current density and thicker deposits. The role of Nd salt concentrations and water content as an additive in the electrochemistry of Nd 3+ in [P 6,6,6,14 ][TFSI] has been studied. The presence of metallic neodymium in the deposits has been confirmed by X-ray photoelectron spectroscopy.