36 research outputs found

    Low cost catalysts for Water Gas Shift reaction based on CuNi over La promoted ceria

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    Proton-exchange membrane fuel cells are of great interest for vehicular applications. A highly pure, sustainably obtained H2 stream is desirable to use as the cell feed. In the water gas shift (WGS) process, large amounts of CO, which is a poison for the cell anode, are removed from a bioalcohol-derived H2 stream before it enters the cell. In this study, Cu–Ni catalysts supported on La-doped ceria were analyzed and studied in the WGS reaction. The supports were prepared by the urea thermal decomposition method with different percentages of La as a promoter of ceria. The metal phase was incorporated by incipient wet impregnation. Many characterization techniques were employed in this work (BET, XRD, SEM, ICP, TPR, OSC), and the relationship between the resulting properties and catalytic performance was investigated to determine the effect of La. A mixture of Cu and Ni was found to be the most effective active phase, having considerable activity and selectivity towards the desired reaction. Low degrees of La doping in ceria enhance oxygen mobility in the lattice. A commercial Ce salt containing La as its main impurity (ca. 2 %) is a convenient precursor, given its good performance and low cost compared to a high-purity salt.Fil: Poggio Fraccari, Eduardo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Rozenblit, Abigail. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Mariño, Fernando Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentin

    Catalytic performance of Ce1-xLnxOy of nanocrystalline Ln (III-IV)-substituted ceria

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    The activity of several lanthanide promoted Ceria in CO oxidation was studied. Samples were obtained by a high yield and sustainable method by urea thermal decomposition. Precursors basic carbonates,Ce1-xLnx(OH)CO3, being Ln = La (III), Sm(III), Gd(III), Pr(III) were prepared in the range of compositions 0 to 30 at.%.These precursors were annealed to moderate temperature obtain Ln-Ce mixed oxides, at 450ºC. These exhibit large surface areas up to 120 m2/g. Their catalytic performance revealed good activity towards CO oxidation (COOX) forall samples. However, a different behavior may be observed for Ln content higher than 20 at.%. By the reactor operation in differential conditions, the activation energy for COOX were obtained for all samples. The rise ofactivation energy as a function of Ln(III-IV) content is analyzed in the frame of phase stability and surface segregationFil: Poggio Fraccari, Eduardo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Mariño, Fernando Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Sorbello, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Jobbagy, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin

    Bi-reforming of Biogas for Hydrogen Production with Sulfur-Resistant Multimetallic Catalyst

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    A multimetallic sample, NiCeSnRh/Al2O3, was tested in methane reforming with a CH4:H2O:CO2 molar ratio equal to 3:2:1. A very stable methane conversion with the time-on-stream was achieved during 20 h. Dimethyl sulfide served as a model sulfur molecule and a sulfurized sample was also tested. This achieved slightly lower conversion with a stable performance for more than 10 h and a minor but continuous decrease of its activity, after this period. The carbon dioxide conversion was always higher than the methane conversion in agreement with the lower H2/CO ratio observed with respect to the theoretical value, 2/1, indicating the sulfur might block the active sites for H2O activation. The analysis of the used catalysts showed graphitic and disordered carbon depositsFunding for open access charge: Universidad de Málaga/CBUA

    Ce-Mn mixed oxides as supports of copper- and nickel-based catalysts for water-gas shift reaction

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    Cerium-manganese mixed oxides with different composition were prepared by co-precipitation, characterized and evaluated for the water–gas shift (WGS) reaction. Base metal (5 wt.% Cu and 5 wt.% Ni) catalysts supported on Ce–Mn mixed oxides were also tested for the WGS reaction. The activity of the bare supports is higher in the mixed samples than in pure ceria or manganese oxide. This result can be explained by a combination of greater reducibility and surface area in the mixed samples. Addition of base metals produces superior WGS catalysts. Particularly, nickel catalysts tested are able to reduce typical CO concentrations entering the WGS process to the CO levels tolerated by phosphoric acid fuel cells in a single unit operated at 400 °C.Centro de Investigación y Desarrollo en Ciencias AplicadasUniversidad de Buenos Aire

    Hydrogen Production from Bioethanol: Behavior of a Carbon Oxide Preferential Oxidation Catalyst

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    Hydrogen is recognized as a promising green energy source, particularly when used to feed a polymer electrolyte membrane fuel cell (PEMFC). Here, hydrogen was obtained by bioethanol steam reforming with CO and CO2 as primary sub products. Since the cell anode is extremely sensitive to poisoning with CO, water-gas shift (WGS) and carbon oxide preferential oxidation (COPROX) reactors were employed for hydrogen purification. Catalysts prepared by our lab were tested at pilot plant scale in both the reformer and COPROX unit, where different active phase distributions, stoichiometric excess of air, and reaction temperatures were tested. The use of two different COPROX units with intermediate air injection was also considered. The as-prepared catalysts showed good stability and performance.Fil: Aliaga, Florencia. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química. Laboratorio de Procesos Catalíticos; ArgentinaFil: Iglesias, Ignacio Daniel. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química. Laboratorio de Procesos Catalíticos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Tejeda, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química. Laboratorio de Procesos Catalíticos; ArgentinaFil: Laborde, Miguel Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química. Laboratorio de Procesos Catalíticos; Argentin

    Desarrollo de catalizadores alternativos para la reacción de water gas shift

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    Grado obtenido: Doctor de la Universidad de Buenos Aires. Área IngenieríaDisciplina: IngenieríaFil: Poggio Fraccari, Eduardo A. Universidad de Buenos Aires. Facultad de IngenieríaInstituto de Tecnologías de Hidrógeno y Energías Sostenibles.(UBA-CONICET

    A comparison of deep learning models applied to Water Gas Shift catalysts for hydrogen purification

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    As a consequence of the renewed interest in the Water Gas Shift reaction a great volume of information was produced. Since a traditional method like the reaction kinetics or mechanism are not capable of dealing with all this information, a deep learning model is convenient to explore to make useful predictions of catalysts performance. In the present work some novel features were included, a measure of reducibility, the crystal size, and the catalysts cost. The Principal Component Analysis indicated that the chosen features of the dataset were not redundant and the suggested novel features strongly influenced the most important components. A Random Forest Regressor was optimized and then trained in order to obtain the feature importance. An Artificial Neural Network was employed after a Grid Search optimization. This model was fed with different sizes of datasets in order to determine its effect on the accuracy of the predictions.Fil: Poggio Fraccari, Eduardo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentina. Universidad de Málaga; EspañaFil: Damián, Caré. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Mariño, Fernando Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentin

    Pr3+ surface fraction in CePr mixed oxides determined by XPS analysis

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    CePr mixed oxides were previously studied as supports for Water Gas Shift catalysts, considering their promising textural and redox properties arising from the presence of a non-stoichiometric oxide. A very small Ce3+ fraction was observed on those oxides, suggesting that Pr3+ion could be responsible for the enhanced activity. Therefore, in-depth XPS analysis is conducted in the present work in order to determine the Pr3+ fraction by fitting the XPS Pr 3d region. Much higher values of reduced Pr ions than Ce ions were observed, confirming the promoter role of the former.Fil: Poggio Fraccari, Eduardo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Baronetti, Graciela Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Mariño, Fernando Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentin

    Study of effectiveness factors with non-uniform catalyst distributions for methane steam reforming

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    In the present work, three kinetic expressions for methane steam reforming with different methane and water partial pressures dependence were studied. Methane effectiveness factors were simulated for spherical uniform pellets (those customarily employed), for several temperatures and water/methane ratios (hereafter called R). It was found that all effectiveness factors decreased with temperature as expected for all the kinetics expressions studied. On the other hand, the evolution with R was strongly dependent on the kinetics analyzed, with an important change in effectiveness factors values, ranging from 30 to 400%. This implies that the most convenient active sites distribution might be dependent on R evolution throughout the reactor. Then, two MSR reactors were simulated, loaded with pelletized catalysts with uniform and eggshell in order to get uniform nomenclature active site distributions. It was found that the one loaded with eggshell in order to get uniform nomenclature pellets saves up to 30% catalysts mass with respect to the uniform catalyst distribution for the same CH4 conversion, reinforcing the importance of active sites distribution.Fil: Iglesias, Ignacio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Poggio Fraccari, Eduardo Arístides. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Giunta, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentin
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