Desarrollo, Producción e Innovación en la Investigación científica
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Item Reservorio nanoscópico de hidrógeno a partie de biorresiduos de cáscara de naranjas.(Univesidsad Tecnológica Nacional., 2022) Juárez , Juliana María; Ledesma , Brenda Cecilia; Anunziata , Oscar Alfredo; Gómez Costa , Marcos Bruno; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Ledesma , Brenda CeciliaEste trabajo aborda el enfoque de valorización de biorresiduos para el desarrollo de un novedoso nanomaterial carbonoso para ser utilizado en la adsorción de hidrógeno como una alternativa en el uso de hidrógeno verde. En esta investigación, los carbones activados se sintetizaron a partir de cáscara de naranja utilizando diferentes condiciones de síntesis. Con los carbones activados obtenidos con la mejor estructura y textura se estudió la adsorción de hidrógeno y los efectos en la meso/microporosidad de estos. La activación del carbón se realizó mediante un proceso químico con ácido fosfórico como agente activador, variando la concentración de ácido, la relación sustrato / agente activador y el tiempo de contacto entre ellos. El mejor material se obtuvo utilizando tiempo de carbonización de 1 h, temperatura de carbonización de 470oC, concentración de ácido fosfórico de 50% en peso y con área BET de 1402 m2 / g. Dicho material mejoró significativamente el comportamiento de almacenamiento de H2 en comparación con el carbón nanoestructurado del tipo CMK-3 (3,1% en peso a -196,15 oC y 10 bar). El material sintetizado es prometedor en la absorción de hidrógeno por fuerzas de enlace débiles (fisisorción).Item Hydrogenation of tetralin in presence of nitrogen using a noble-bimetallic couple over a Ti-modified SBA-15.(Univesidsad Tecnológica Nacional., 2016) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Pecchi, Gina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Ledesma , Brenda CeciliaMonometallic Pt- and bimetallic Pt-Ir-modified Ti-SBA-15 were used in the hydrogenation of tetralin to decalin in the presence of 150 ppm of N as quinoline and indole at 250 ◦C and 15 atm of pressure of hydrogen, using a Parr reactor. The catalyst was synthesized using sol-gel method and Ti was added during the synthesis using Tetraethyl Orthotitanate. Pt/Ir was added by wetness impregnation. The catalysts prepared were extensively characterized by X-ray diffraction (XRD), N2 adsorption isotherms, UV–vis DRS, Raman spectroscopy, XPS, TEM-EDS and TPR. UV–vis-DRS and Raman spectroscopy confirmed that Ti was incorporated in tetrahedral coordination in the framework of the SBA-15. The analysis showed that the mesoporous structure was maintained after metal incorporation and Ti incorporation helps to reduce significantly the size of the metals clusters and improves its dispersion considerably. Pt-Ir/Ti-SBA 15 was the most active catalyst. The experimental data were quantitatively represented by a modified Langmuir-Hinshelwood type rate equation. The preliminary results show these materials as a promising catalyst for HDT reactions.Item Optimization of the synthesis of SBA-3 mesoporous materials by experimental desing.(Univesidsad Tecnológica Nacional., 2015) Ponte , María Virginia; Rivoira , Lorena Paola; Cussa , jorgelina; Martínez , María Laura; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Anunziata; Cussa , jorgelina; Rivoira , Lorena PaolaSBA-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).Item Synthesis and characterization of 2D-hexagonal, 3D-hexagonal and cubic mesoporous materials using CTAB and silica gel.(Univesidsad Tecnológica Nacional., 2016) Martínez , María Laura; Falcón, Horacio; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar AlfredoHighly ordered mesoporous materials SBA family (Santa Barbara Amorphous), with symmetry of two-dimen sional (2D)-hexagonal SBA-3, three-dimensional (3D)-hexagonal P63/mmc (SBA-7) and cubic Pm3n (SBA-1) were synthesized by a simple and easy procedure, designed using silica gel as a silicon source, CTAB (cetyltrimethylammonium bromide) as a structure-directing agent, in highly acidic conditions. The effect of the variation of temperature and reaction time allowed us to obtain the optimum condition to prepare SBA-1, SBA-3 and SBA-7 materials. The sodium silicate generated “in situ” by dissolution of the silica gel, at different con centrations of NaOH and the variation of the synthesis temperature and reaction time are the three factors which allow obtaining different SBA phases. Thus, the best SBA-3, SBA-1 and SBA-7 materials with well-ordered meso- porous system can be obtained in the range of 0.8, 0.9 and 1.0 NaOH concentration and 30 and 25 °C and 45, 2880, 1440 min (for SBA-3, SBA-1 and SBA-7 respectively)Item Vanadium oxide supported on mesoporous SBA-15 modified with AI and Ga as a highly active catalyst in the ODS of DBT.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María LauraVanadium oxides supported on mesoporous SBA-15 catalysts with different vanadium loadings were studied in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. The catalytic activity was improved when SBA-15 framework was modified by adding Al and Ga. Structural and textural characterization of the catalysts were performed by means of XRD, N2 adsorption, UVeVis eDRS, XPS, NMR, TEM, Raman, TPR and Py-FTIR. UVeViseDRS and Raman demonstrated that highly dispersed vanadium VO—3 species are responsible for the high activity in the sulfur removal. The Ga modified support with an intermediate V/Si ratio of 1/30 was the most active catalyst for ODS of DBT, using hydrogen peroxide as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at a short time in mild conditions. Gallium and aluminum incorporation into the support modified suc cessfully the nature of the SBA-15 surface by generating Bronsted and Lewis acidity. The interaction between the acid sites with the active vanadium sites improved the activity of the catalysts. The high dispersion depended on the vanadium loading and on the nature of the support. The more acidic support allowed better dispersion of the vanadium species due to stronger interaction metal-support. The reusability of the catalysts indicates that vanadium oxide supported on mesoporous SBA-15 modified with Ga and Al are potential catalysts for the ODS of dibenzothiopheneItem Novel and simple one-pot method for the synthesis of Ti02 modified-CMK-3 applied in oxidative desulfurization of refractory organosulfur compounds.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Ledesma , Brenda Cecilia; Juárez , Juliana María; Beltramone , Andrea Raquel; Juárez , Juliana María; Ledesma , Brenda CeciliaTi-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The precursors of silicon, carbon and titanium are incorporated together with the other components during the only step of the synthesis. The method developed here, allows reducing time and energy consumption by 60% and thus, the cost of the overall process of synthesis. Structural and textural characterization of the titanium modified-mesoporous carbon was performed by N2 adsorption, XRD, UV–Vis DRS, XPS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was synthesized by dif- ferent methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur com- pounds. The catalyst prepared by the one-pot method is capable to oxidize high amount of sulfur (2000 ppm) in only 30 min of reaction time at 60–80 °C. The good performance and stability of the catalyst prepared using a novel synthesis method was attributed to well dispersed anatase nanospecies over the high area mesoporous carbon. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for ODS reactions.Item Noble-bimetallic supported CMK-3 as a novel catalyst for hydrogenation of tetralin in the presence of sulfur and nitrogen.(Univesidsad Tecnológica Nacional., 2016) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Juárez , Juliana María; Ledesma , Brenda CeciliaCarbon ordered mesoporous CMK-3 with high surface area and high pore volume promotes a very good dispersion of Pt or Ir monometallic and Pt-Ir-bimetallic crystallites in the carbon framework. High active and stable nanospecies are responsible for the good activity and selectivity found in the hydrogenation of tetralin to decalin in the presence of N as indole and S as dibenzothiophene under mild conditions in a Batch reactor. The catalysts prepared were extensively characterized by XRD, N2 adsorption isotherms, XPS, TEM, ICP, CO Chemisorption and TPR. The analysis showed that the carbon mesoporous structure was maintained after metal incorporation, and very high dispersed metal-supported catalyst was obtained. The activity was compared using the turnover number, Pt-Ir-CMK-3 being the most active cat alyst in the presence of the inhibitors. The bimetallic catalyst showed more resistance to inhibition than monometallic catalysts. The reusability of Pt-Ir-CMK-3 suggests that it is a potential catalyst for hydrotreating reactions.Item Pt-Pd-F/AI203catalyst applied in the HDT process.(Univesidsad Tecnológica Nacional., 2015) Balangero, Gerardo Simón; Falcón , Horacio; Beltramone , Andrea RaquelThe inhibiting effect of basic and non-basic nitrogen compounds on the hydrogenation of polyaromatic compounds and on the hydrodesulphurization (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6DMDBT), has been investigated on Pt-Pd-F/Al2O3 and compared with a commercial NiMo hydrotreating catalyst. Langmuir-Hinshelwood type rate equations were used to describe the reaction kinetics accurately with physically meaningful and well identified parameter values. Model parameters were tuned by fitting experimental data obtained in a continuous flow reactor at 345°C, 1000 psi pressure and different contact times. Pt-Pd-F/Al2O3 was more active than NiMo catalyst and conversion remained constant during 24 h of TOS. The model was able to correctly interpret all the experimental data. Parameter estimation results showed that phenanthrene and naphthalene inhibited the tetralin hydrogenation rate, whereas naphthalene and tetralin had no appreciable effect on the rate of phenanthrene conversion. This inhibition could be explained by the competitive adsorption and was described in the kinetic model by adsorption terms obtained from the multicomponent experiments. The inhibiting effect of different nitrogen compounds on the polyaromatic hydrogenation was determined. The following nitrogen compounds were investigated in this study: quinoline, 1,2,3,4-tetrahydroquinoline, indole, and indoline. The degree of inhibition was expressed in terms of an apparent adsorption constant derived from the kinetics.The inhibiting effect on the HDS of DBT and 4,6 DBT followed the same trendItem 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; Anunziata , Oscar Alfredo; Anunziata; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma , Brenda CeciliaBimetallic 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.Item Eliminación de azufre mediante desulfuración oxidativa con Ti-SBA-16. Parte I. Síntesis y caracterización.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Ponte , María Virginia; Martínez , María Laura; Beltramone , Andrea Raquel; Martínez , María Laura; Ponte , María Virginia; Ledesma , Brenda Cecilia; Ledesma , Lorena Paola; Vallés , Verónica AlejandraSe desarrollaron catalizadores tipo SBA-16 modificados con Ti como TiO2 y como heteroatomo y se probaron en la desulfuración oxidativa (ODS) del dibenzotiofeno predominante en el combustible líquido. Se utilizó TiO2 puro como referencia para comparar la actividad catalitica. Los catalizadores fueron caracterizados mediante análisis químico, XRD, EDX y TEM. El estado de coordinación tetraédrico del titanio (en la muestra de Ti-SBA-16) u octaédrico (en la muestra de TiO2/SBA-16) en la matriz de sílice se determinó por XPS, UV-vis DRS, FTIR, Raman y XANES. La actividad catalítica se muestra en la Parte 2 de este trabajo.