Browsing by Keyword "Catalysis"
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Item Catalytic membrane reactor for the production of biofuels(2016-06-15) Liuzzi, Dalia; Pérez-Alonso, Francisco José; Fierro, José Luis G.; Rojas, Sergio; Van Wijk, Frank L.; Roghair, Ivo; Van Sint Annaland, Martin; Fernandez, Ekain; Viviente, Jose Luis; Tanaka, D. A.Pacheco; TECNOLOGÍAS DE HIDRÓGENO; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe H2-distributed feeding concept using Pd/Ag-based membranes and an Ru-based catalyst in a Packed Bed Membrane Reactor (H2-PBMR) for the synthesis of biofuels via the so-called Fischer-Tropsch Synthesis has been demonstrated. The most successful approach resulted when H2-poor syngas (H2/CO = 1) typically obtained from the gasification of biomass was fed directly through the reaction chamber, i.e., to the catalyst bed, whereas the H2 needed to reach the proper stoichiometry for the FTS (H2/CO = 2) was admitted, and properly distributed, into the catalyst bed through the Pd/Ag-based membrane by flowing H2/He mixtures at the retentate side of the membrane. Under the optimum reaction conditions, the CO conversion measured with the H2-distributed feeding concept is lower than that obtained in a conventional Packed Bed Reactor with H2/CO = 2 (37.9 vs 50.7%), but significantly higher than that obtained in a conventional reactor with H2/CO = 1 (14.1%). Remarkably, the productivity towards high-molecular hydrocarbons increases by almost 70% and the methane production decreases by one order of magnitude when using the H2-distributed feeding concept in a Packed Bed Membrane Reactor.Item CuO/ZnO catalysts for methanol steam reforming: The role of the support polarity ratio and surface area(2015-09-01) Mateos-Pedrero, Cecilia; Silva, Hugo; Pacheco Tanaka, David A.; Liguori, Simona; Iulianelli, Adolfo; Basile, Angelo; Mendes, Adelio; Ligouri, Simona; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe effect of surface area and polarity ratio of ZnO support on the catalytic properties of CuO/ZnO catalyst for methanol steam reforming (MSR) are studied. The surface area of ZnO was varied changing the calcination temperature, and its polarity ratio was modified using different Zn precursors, zinc acetate and zinc nitrate. It was found that the copper dispersion and copper surface area increase with the surface area of the ZnO support, and the polarity ratio of ZnO strongly influences the reducibility of copper species. A higher polarity ratio promotes the reducibility, which is attributed to a strong interaction between copper and the more polar ZnO support. Interestingly, it was observed that the selectivity of CuO/ZnO catalysts (lower CO yield) increases with the polarity ratio of ZnO carriers. As another key result, CuO/ZnOAc375 catalyst has proven to be more selective (up to 90%) than a reference CuO/ZnO/Al2O3 sample (G66-MR, Süd Chemie).The activity of the best performing catalyst, CuO/ZnOAc-375, was assessed in a Pd-composite membrane reactor and in a conventional packed-bed reactor. A hydrogen recovery of ca. 75% and a hydrogen permeate purity of more than 90% was obtained. The Pd-based membrane reactor allowed to improve the methanol conversion, by partially suppressing the methanol steam reforming backward reaction, besides upgrading the reformate hydrogen purity for use in HT-PEMFC.Item Effect of water matrix on photocatalytic degradation and general kinetic modeling(2016-01-01) RIOJA, NEREA; ZORITA, SAIOA; PEÑAS, FRANCISCO JAVIER; ADAPTACIÓN AL CAMBIO CLIMÁTICOPhotocatalysis employing TiO2 nanoparticles was studied to assess the effect of aqueous matrix nature in the degradation of clofibric acid (CFA) under UV-A radiation. Aeroxide TiO2-P25 at 0.50 g/L was the most effective catalyst among those tested, with a CFA degradation of 98.5% after 15 min. The CFA photodegradation in environmental waters (tap, mineral, river and recycled wastewater) and in the presence of inorganic (NaCl, FeCl3, FeCl2, AlCl3, CaCl2, Al-2(SO4)(3), Fe-2(SO4)(3), Na2SO4, NaHCO3, and Na2CO3) and organic compounds (humic acids, and a surfactant) commonly found in real waters was compared to that obtained in pure water. In general, the removal efficiency decreased with inorganic salts, especially with sulfates and carbonates (>70% deactivation), and also in environmental waters (>90%). A general kinetic model has been developed to describe the CFA photo degradation depending on the type and concentration of substances present in water. The first-order kinetic constants were estimated by defining a characteristic parameter for each ion species tested in the aqueous matrix. High correlation (R-2 >0.99 in most cases) was observed between experimental CFA concentrations and those predicted by the model.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 Enhanced CO2 Methanation by New Microstructured Reactor Concept and Design(2019-06-15) Pérez, Susana; Aragón, Jorge J.; Peciña, Iñigo; Garcia-Suarez, Eduardo J.; VALORIZACIÓN DE RESIDUOS; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOS; Tecnalia Research & InnovationA novel multichannel minireactor with channel internal diameter in the range of millimeters has been conceptually designed and constructed. Its configuration confers to the new concept reactor some features and advantages compared to conventional fixed-bed reactors g.e. better mass-transfer, avoid hot-spots formation, increased performance (10–20%). Consequently, this new reactor concept is ideal to be applied to exothermic reactions such as the Sabatier reaction that demands continuous removal of the heat produced to avoid hot-spot formation and the sintering of the catalyst. Thanks to its configuration, this reactor could control effectively the heat generated by the reaction and several tests were carried out to validate the reactor features. The results obtained demonstrate that the catalysts activity in the reaction is improved with the application of the novel reactor respect the conventional fixed- and fluidized-bed ones and neither catalyst sintering, nor pressure drop was appreciated during the catalytic tests. At the best reaction conditions, Tecnalia’s multichannel minireactor can handle 820 Nm3/h of CO2 per square meter of channel section showing the enormous potential of the new reactor concept.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 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 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 Pore flow-through catalytic membrane reactor for steam methane reforming: characterization and performance(2022-07-12) Angulo, M.; Agirre, I.; Arratibel, A.; Llosa Tanco, M. A.; Pacheco Tanaka, D. A.; Barrio, V. L.; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSA series of pore flow-through catalytic nonselective membrane reactors (PTCMRs) were studied for steam methane reforming (SMR) in the 500 to 900 °C temperature range under 10 barg pressure and a steam-to-carbon ratio of 5. The reactants flow through the pores of the membrane where they react on contact with the Pd nanoparticles. Various reactor configurations were prepared and tested with porous α-Al2O3-based ceramic tubes with one or more γ-Al2O3/YSZ layers on the external surface. The palladium content and dispersion affect the catalytic activity of the reactors and the results show that the efficiency of the reactions depends on the number of γ-Al2O3/YSZ layers.Item Ultra-Fast Supercritical Hydrothermal Synthesis of Tobermorite under Thermodynamically Metastable Conditions(2017-03-13) Diez-Garcia, Marta; Gaitero, Juan J.; Dolado, Jorge S.; Aymonier, Cyril; Tecnalia Research & Innovation; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNTobermorite is a fibrillar mineral of the family of calcium silicates. In spite of not being abundant in nature, its structure and properties are reasonably well known because of its interest in the construction industry. Currently, tobermorite is synthesized by hydrothermal methods at mild temperatures. The problem is that such processes are very slow (>5 h) and temperature cannot be increased to speed them up because tobermorite is metastable over 130 °C. Furthermore the product obtained is generally foil-like and not very crystalline. Herein we propose an alternative synthesis method based on the use of a continuous flow reactor and supercritical water. In spite of the high temperature, the transformation of tobermorite to more stable phases can be prevented by accurately controlling the reaction time. As a result, highly crystalline fibrillar tobermorite can be obtained in just a few seconds under thermodynamically metastable conditions.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.