Desarrollo, Producción e Innovación en la Investigación científica

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Author: search.filters.author.Rivoira, Lorena Paola

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    Experimental desing optimization of the ods of DBT using V2O5 supported on GA-SBA-15.
    (Univesidsad Tecnológica Nacional, 2017) Rivoira, Lorena Paola; Cussa, jorgelina; Martínez , María Laura; Beltramone, Andrea Raquel; Martínez , María; Cussa, jorgelina
    Experiment design-response surface methodology (RSM) was used in this work to model and optimize one response in the oxidative desulfurization of dibenzothiophene with hydrogen peroxide using VOx-Ga-SBA-15 catalysts with different Ga/Si and V/Si ratios. In this study, we analyze the influence of the nature of the catalyst (metal/Si ratio), the catalyst/substrate ratio and the oxidant/substrate ratio as factors for the design. The response analyzed was conversion at 15 min of reaction time. The response surfaces were obtained with the Box–Behnken Design, finding the best combination between the reaction parameters that allowed optimizing the process. By applying the statistic methodology, the higher levels of the objective function were obtained employing the catalyst with Ga/Si and V/Si ratios of 1/15 and 1/25, respectively. Structural and textural characterization of the catalysts were performed by means of XRD, N2 adsorption, UV–Vis–DRS, XPS, NMR, TEM, Raman, TPR and Py-FTIR. UV–Vis–DRS and Raman demonstrated that highly dispersed vanadium pentoxide crystallites are responsible for the high activity in the sulfur removal. The high dispersion depended on the vanadium loading and on the nature of the support.
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    Tetralin hydrogenation over Ir-Pt/SBA-15. optimization by experimental desing.
    (Univesidsad Tecnológica Nacional, 2024) Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Rivoira, Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Ledesma, Brenda
    Bimetallic catalysts have received considerable attention for hydrotreating (HDT) because they show high activity. The features of the catalysts here studied are going to be correlated with their catalytic performance in the hydrogenation of tetralin at mild conditions. The final goal is to find the optimal proportion of each metal in order to be more active and the best reaction conditions (temperature and amount of catalyst). The statistical experiments design is the process of planning an experiment to obtain appropriate data that can be analyzed by statistical methods, to produce concrete and valid conclusions. One of the main advantages in the response curve is to visualize the response for all levels of the experimental factors Experiment design response surface methodology (RSM) is used in this work to model and to optimize the process. Platinum and Iridium nanoparticles were incorporated into SBA-15 support by the wet co impregnation method. Ir content was set as 1wt. % and Pt was varied from 0 to 1wt. %. The catalysts were characterized by XRD, BET, XPS, TEM, ICP and TPR. XRD profiles are characteristic of the two-dimensional p6mm hexagonal mesostructure with d100 spacing of 10.16 nm; where the d100 spacing upon Ir and Pt incorporation were quite similar to pristine SBA-15. The TEM images and XPS demonstrate that the metal particles were mainly present inside the porous and XPS and TPR corroborated the reduced state of the metals. The catalytic activity was measured in a 4563Parr reactor at 15 atm of hydrogen and 360 rpm. Feed consisted in 50 mL of tetralin in Dodecane, the amount of tetralin is set according to the ratio of catalyst mass/mass reagent corresponding to each reaction. The application of this methodology allows a better understanding of the influence of the different factors: content of metal on catalyst (A), relationship: mass of catalyst/reagent mass (B) and reaction temperature (C), on two responses: conversion at 3 h and at 5 h of reaction time. These factors were carefully selected taking account the influence of the parameters in the reaction. The design was analyzed by Statgraphics and Statistica Soft. We found that, the variable Catalyst has the best influence over the Conversion at the 95.0% confidence level, according to the Pareto.
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    Ir-Pt/SBA-15 applied in the optimization of tetralin hydrogenation.
    (Univesidsad Tecnológica Nacional, 2015) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Rivoira, Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Cussa , jorgelina; Ledesma , Brenda
    Bimetallic catalysts have received considerable attention for hydrotreating (HDT) because they show high activity. The features of the catalysts here studied are going to be correlated with their catalytic performance in the hydrogenation of tetralin at mild conditions. The final goal is to find the optimal proportion of each metal in order to be more active and the best reaction conditions (temperature and amount of catalyst). The statistical experiments design is the process of planning an experiment to obtain appropriate data that can be analyzed by statistical methods, to produce concrete and valid conclusions. One of the main advantages in the response curve is to visualize the response for all levels of the experimental factors Experiment design response surface methodology (RSM) is used in this work to model and to optimize the process. Platinum and Iridium nanoparticles were incorporated into SBA-15 support by the wet co-impregnation method. Ir content was set as 1wt. % and Pt was varied from 0 to 1wt. %. The catalysts were characterized by XRD, BET, XPS, TEM, ICP and TPR. XRD profiles are characteristic of the two-dimensional p6mm hexagonal mesostructure with d100 spacing of 10.16 nm; where the d100 spacing upon Ir and Pt incorporation were quite similar to pristine SBA-15. The TEM images and XPS demonstrate that the metal particles were mainly present inside the porous and XPS and TPR corroborated the reduced state of the metals. The catalytic activity was measured in a 4563Parr reactor at 15 atm of hydrogen and 360 rpm. Feed consisted in 50 mL of tetralin in Dodecane, the amount of tetralin is set according to the ratio of catalyst mass/mass reagent corresponding to each reaction. The application of this methodology allows a better understanding of the influence of the different factors: content of metal on catalyst (A), relationship: mass of catalyst/reagent mass (B) and reaction temperature (C), on two responses: conversion at 3 h and at 5 h of reaction time. These factors were carefully selected taking account the influence of the parameters in the reaction. The design was analyzed by Statgraphics and Statistica Soft. We found that, the variable Catalyst has the best influence over the Conversion at the 95.0% confidence level, according to the Pareto.
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    Hidrogenación de tetralin utilizando un catalizador bifuncional de iridio/platino-SBA-15.
    (Univesidsad Tecnológica Nacional, 2014) Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Rivoira, Lorena Paola; Cussa , jorgelina; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María; Cussa , jorgelina; Ledesma, Brenda
    Los catalizadores bimetálicos de Pt–Pd han recibido considerable atención debido a que demuestran tener una alta actividad en una amplia variedad de aplicaciones catalíticas (1). Con alta actividad, selectividad y estabilidad, comparada con catalizadores monometálicos de Pt y Pd. Por ejemplo, catalizadores bimetálicos Pt-Pd muestran tener mayor resistencia frente a envenenamientos en comparación con catalizadores de Pt (2-4). Las características estudiadas del catalizador serán correlacionadas con su performance catalítica en la hidrogenación del tetralin. El objetivo final es encontrar la proporción óptima de cada uno de los metales de forma de lograr la mayor actividad en dicho proceso.
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    Optimization of the synthesis of SBA-3 mesoporous materials by experimental design
    (Elsevier Inc., 2016-02-18) Ponte, María Virignia; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, Maria Laura; Beltramone, Andrea Raquel; Anunziata, Oscar Alfredo
    SBA-3 mesoporous materials are characterized by hexagonal regular arrangements of channels with diameters >2 nm, high specific surface areas and high specific pore volumes. In the work reported herein, experimental design-response surface methodology (RSM) is used to model and optimize the synthesis conditions for SBA-3 mesoporous materials. In this study, we evaluate the influences of surfactant/silica source molar ratios, aging times, temperature and pH on the synthesis of SBA-3 mesoporous materials by analyzing the XRD intensities pertaining to the [100] signal. Response surfaces were obtained using the BoxeBehnken design, and the combination of reaction parameters was optimized. By applying statistical methodology, higher levels of the objective function (XRD intensities pertaining to the [100] signal) were obtained using cetyltrimethylammonium bromide (CTAB)/tetraethyl orthosilicate (TEOS) molar ratios of 0.07 and 0.16, HCl/TEOS molar ratios of 8 and 11, reaction temperatures of 35 and 45 ◦C and aging times of 12e24 h. The mesoporous SBA-3 samples obtained were characterized using small-angle X-ray powder diffraction (XRD), BET, FTIR and 29Si NMR-MAS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
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    EXperimental design optimization of the ODS of DBT using vanadium oXide supported on mesoporous Ga-SBA-15
    (2020) Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Beltramone, Andrea Raquel
    EXperiment design-response surface methodology is applied in this work to model and optimize the o Xidation of dibenzothiophene (DBT) using VOX-Ga-SBA-15 catalyst. The analyzed variables are the influence of the nature of the catalyst (V and Ga loading), the s ubstrate/catalyst mass ratio (g DBT/g of catalyst) and the o Xidant/substrate molar ratio (H2O2/DBT). The response analyzed is conversion of DBT at 15 min of reaction time. A set of re- sponse surfaces were obtained applying the BoX-Behnken Design. Based on statistical methodology it was pos- sible to find the best arrangement between the amounts of the gallium heteroatom and the vanadium active species. The higher levels of the objective function were obtained employing the catalyst with 4 wt.% of gallium and 6 wt.% of vanadium; the optimal ratio between g DBT/g of catalyst was 4 and the molar ratio between H2O2/DBT was 5. Gallium incorporation as heteroatom in tetrahedral position allowed the better anchorage ofthe active species of vanadium, generating a very well dispersed catalyst. The optimized catalyst minimized the mass transfer limitation and moreover, was active after several recycles. The best catalyst was likewise very active for the oXidation of the most refractory sulfur compounds as benzothiophene and 4,6-dimetyldi- benzothiopene.
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    Iron-modified mesoporous materials as catalysts for ODS of sulfur compounds
    (2020) Rivoira, Lorena Paola; Juárez, Juliana María; Martínez, María Laura; Beltramone, Andrea Raquel
    Fe-modified mesoporous catalysts were used in the ODS of DBTs using H2O2 as oXidant and acetonitrile as solvent. SBA-15, MCM-48, CMK-3 and CMK-1 were used as supports. Iron was incorporated using iron nitrate by wetness impregnation. The catalysts were characterized by XRD, N2 isotherms, TEM, XPS and ICP. We developed catalysts with high specific surface area, pore volume and narrow mesopore size distribution and highly dis- persed Fe- species. The catalysts were tested in the o Xidative desulfurization of different sulfur compounds as benzothiophene, dibenzothiopene and 4,6-dimethyl dibenzothiopene. The catalyst prepared using CMK-3 as support was the most active for the ODS reaction. The good activity was related with the high dispersion of the iron oXides, mainly in the magnetite phase. Temperature, hydrogen peroXide and sulfur initial concentration were studied using Fe-CMK-3 in the oXidation of DBT. The optimal operation conditions were determined. Fe- CMK-3 is an active and stable catalyst to be applied in the industrial process of ODS.
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    Catalytic oxidation of sulfur compounds over Ce-SBA-15 and Ce-Zr-SBA-15
    (2021) Rivoira, Lorena Paola; Vallés, Verónica Alejandra; Martínez, María Laura; Yanika, Sa-ngasaeng; Siriporn, Jongpatiwut
    The catalytic oXidation of different sulfur compounds, commonly present in liquid fuel, was studied over a series of ceria and ceria-zirconium based oXidation mesoporous catalysts. SBA-15 was synthesized using sol-gel method and Ce and Ce-Zr were added by two different procedures: i) directly during the synthesis and ii) via post- synthesis method. The catalysts were characterized by XRD, N2 adsorption isotherms, XPS, DRUV-Vis, TEM, SEM and Py-FTIR. Low angle XRD, N2 isotherms and TEM confirmed that the structure was not changed after metal incorporation. Wide angle XRD, UV–vis-DRS, XPS and TEM determined that the catalysts prepared by direct synthesis presented higher dispersion of Ce oXides, smaller particle size and isolated Zr4+ species. FTIR of adsorbed/desorbed pyridine indicated that zirconium as promoter increases the Lewis acidity of the catalysts, especially during direct synthesis. Ce-Zr-SBA-15 catalyst prepared by direct synthesis was very active in the oXidation of dibenzothiophene, 4,6-dimethyl dibenzothiophene and benzothiophene using hydrogen peroXide (H2O2) as oXidant agent and acetonitrile as polar solvent. The effect of acidity in the catalyst, hydrogen peroXide concentration and temperature was studied. The deactivation test demonstrated that the catalyst is stable and adequate for the industrial process.
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    Activated carbons synthetized from orange peel to produce clean energy
    (2022) Rivoira, Lorena Paola; Gómez Costa, Marcos Bruno; Ledesma, Brenda Cecilia; Beltramone, Andrea Raquel
    As we all know, a clean energy revolution is taking place all over the world in pursuit of replacing oil. The present work stands out an environmental point of view by proposing biomass wastes from different industrial areas to produce not only a biofuel but also as raw material to synthetize the catalyst involved in the HDO reaction. In this way the process ceases to rely on the antiquated and obsolete linear economy where products, services, wastes, materials, water and energy have a beginning and an end to become a process with greater tendency to the modern circular economy, closely related to the idea of sustainability. Products, materials and resources are expected to last as long as possible while minimizing waste as much as possible too. Agricultural and forestry waste are available everywhere being a low cost raw material and it is possible to provide added value to the organic wastes of small and medium size enterprises. The hydrodeoxygenation (HDO) of guaiacol has been performed in a batch reactor under 12 atm of H2 and different temperatures over activated carbon synthetized from orange peel discarded from juice industry. Carbon activation was carried out through a chemical process with phosphoric acid as an activating agent, varying the acid concentration, the ratio substrate/activating agent and time of contact between them. The best support was obtained using carbonization time of 1 h, temperature of carbonization of 470oC, phosphoric acid concentration of 50 wt.% and with BET area of 1429 m2/g. Subsequently, the metallic nanoparticles were deposited in the activated carbon to use the solid as a catalytic material for the hydrodeoxygenation of guaiacol. The catalytic material was modified with metallic nanoparticles of Pt. The catalysts were characterized by means of X-ray diffraction, N2 isotherms, XPS, SEM and TEM. Good structure, narrow pore size distribution and high platinum dispersion were achieved in the synthesized catalysts. The objective of this investigation is the evaluation of the catalytic activity and to compare it with SBA-15 support studied previously. The catalyst presented excellent performance for biofuels generation.
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    New catalyst source applied in biofuel manufacturing
    (2020) Rivoira, Lorena Paola; Ledesma, Brenda Cecilia; Gómez Costa, Marcos Bruno; Beltramone, Andrea Raquel
    A clean energy revolution is taking place all over the world in pursuit of replacing oil. This work stands out an environmental point of view by proposing biomass wastes from different industrial areas to produce not only a biofuel but also as raw material to synthetize the catalyst involved in the HDO reaction. In this way the process ceases to rely on the antiquated and obsolete linear economy where products, services, wastes, materials, water and energy have a beginning and an end to become a process with greater tendency to the modern circular economy, closely related to the idea of sustainability. Products, materials and resources are expected to last as long as possible while minimizing waste as much as possible too. Agricultural and forestry waste are available everywhere being a low cost raw material and it is possible to provide added value to the organic wastes of small and medium size enterprises. The hydrodeoxygenation (HDO) of guaiacol has been performed in a batch reactor under 12 atm of H2 and different temperatures over activated carbon synthetized from orange peel discarded from juice industry. Carbon activation was carried out through a chemical process with phosphoric acid as an activating agent, varying the acid concentration, the ratio substrate/activating agent and time of contact between them. The best support was obtained using carbonization time of 1 h, temperature of carbonization of 470oC, phosphoric acid concentration of 50 wt.% and with BET area of 1429 m2/g. Subsequently, the metallic nanoparticles were deposited in the activated carbon to use the solid as a catalytic material for the hydrodeoxygenation of guaiacol. The catalytic material was modified with metallic nanoparticles of Pt. The catalysts were characterized by means of X-ray diffraction, N2 isotherms, XPS, SEM and TEM. Good structure, narrow pore size distribution and high platinum dispersion were achieved in the synthesized catalysts. The objective of this investigation is the evaluation of the catalytic activity and to compare it with SBA-15 support studied previously. The catalyst presented excellent performance for biofuels generation.