Hydroisomerization–cracking of n-octane on Pt/WO42−–ZrO2 and Pt/SO42−–ZrO2: Effect of Pt load on catalyst performance

The hydroconversion (isomerization–cracking) of n-octane was studied at 300°C, 1.5 MPa, WHSV=4 and H2/nC8=6 using oxoanion promoted zirconia with different Pt concentrations (0.1, 0.5 and 1%) as catalysts. Tungstate was added to zirconia by impregnation with ammonium meta-tungstate or tungstic acid solutions and calcined at 800°C. Sulfate was added by impregnation with 2N H2SO4 and calcined at 620°C. Isooctanes are intermediate products that are cracked to C3–C5 alkanes with predominance of isoalkanes. Sulfate zirconia is the most active and selective catalyst to cracking products. The addition of 0.1% of Pt produces an increase in activity and stability, respect of the support without metal. However, the increase in Pt content (0.5 and 1.0%) produces a decrease in nC8 conversion and in cracking products. The metallic properties of Pt are decreased by its strong interaction with the support, mainly with sulfate zirconia; at the same time, Pt decreases the acid cracking activity of the support.Fil: Grau, Javier Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

LIQUID-PHASE SELECTIVE HYDROGENATION OF 1-HEPTYNE OVER Ni/Al2O3. EFFECT OF THE REACTION TEMPERATURE

En este trabajo fue evaluado el efecto de la temperatura de reacción en la hidrogenación selectiva de 1-heptino a 1-hepteno usando un catalizador de níquel soportado sobre γ -alúmina. Fueron estudiadas diferentes temperaturas operacionales (273, 303 y 323 K), obteniéndose mayor conversión total del reactivo a la mayor temperatura, con una selectividad próxima al 90%. El catalizador de níquel preparado puede considerarse como una alternativa más económica a nivel industrial frente a los ya conocidos catalizadores de paladio, no sólo debido al bajo costo del metal sino también debido a su bajo contenido metálico (3,6% en masa). El catalizador fue caracterizado por Difracción de Rayos X, Reducción a Temperatura Programada y Espectroscopía Fotoelectrónica de Rayos X. Estas indicaron la presencia de óxido de níquel a nivel másico con fuertes interacciones con el soporte y la existencia de especies electro-deficientes de níquel a nivel superficial quienes serían las especies activas durante la hidrogenación del alquino terminal.Fil: Maccarrone, María Juliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Lederhos, Cecilia Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Badano, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Quiroga, Monica Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Effect of water vapor on the activity of Pt-Pd/Al2O3 catalysts for methane combustion

A study on the deactivation phenomena affecting the catalysts of small-scale natural gas catalytic combustors was undertaken in this work. The influence of simulated aging pretreatments on the activity of Pt-Pd catalysts supported over gamma alumina for the catalytic combustion of CH4 was assessed under atmospheric conditions and in the 50–950 °C temperature range. Accelerated deactivation tests consisted of steaming at temperatures between 500–800 °C. The results showed that the activity of the deactivated catalysts depended on two opposite phenomena. An enhancement of the activity was encountered for low aging temperatures and was addressed to chlorine (Cl) elimination (as detected by chemical analysis). Conversely, at higher temperatures the accelerated aging treatment produced a decrease in the activity, and this was allegedly linked to a decrease in the available metal surface area produced by sintering. During the catalyst lifespan and under real operation conditions, a first period is therefore expected where the catalytic activity improves due to the Cl elimination by the water (H2O) produced during combustion. Afterwards, the activity would decrease because of the sintering of the metal phase. Both processes, Cl elimination and sintering, occur simultaneously. Five different catalyst formulations with variable Pt and Pd contents were tried and 0.4%Pt-0.8%Pd was found to be the most active. The results found are discussed in terms of the activity of the monometallic catalysts, the degree of interaction of the Pt and Pd phases and the previously mentioned phenomena of sintering and Cl elimination.Fil: Pieck, Carlos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Peirotti, Eduardo M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Pt/SO42−-ZrO2 catalysts prepared from Pt organometallic compounds

New Pt/SO42−-ZrO2 catalysts were prepared using precalcined SO42−-ZrO2 and organometallic Pt precursors. The objective was to obtain a bifunctional catalyst with improved metal properties, which are mostly suppressed in Pt/SO42−-ZrO2 prepared in a standard fashion. The synthesis route used low temperatures to form the Pt particles in order to avoid sulfate decomposition and Pt poisoning. The use of precalcined zirconia decreased ionic diffusion, related to crystallization of the gel and encapsulation of Pt particles. As detected by TPR and cyclohexane dehydrogenation tests, after reducing at 270 °C, Pt on the new catalyst had metallic properties. Its dehydrogenation activity was higher than that of a standard Pt/SO42−-ZrO2 catalyst (prepared from H2PtCl6). After activating in air at 300 °C, its activity for n-butane isomerization (300 °C, 1 atm., H2:n-C4=6, WHSV=1 h−1) was low, very likely because of incomplete elimination of adsorbed water. After activation in air at 600 °C, the isomerization activity was almost similar to that of standard Pt/SO42−-ZrO2 but the dehydrogenation activity decreased to negligible values. The deleterious interaction between Pt and SO42−-ZrO2 that occurred during calcination was possibly related to oxidation of the metal. On the other side, high reduction temperatures did not enhance the metal activity beyond the level obtained after reducing at 270 °C. On the contrary, the higher the reduction temperature, the lower the activity for cyclohexane dehydrogenation that was obtained. This effect was seemingly related to poisoning by sulfur compounds. The new materials could be potentially useful for reacting systems needing a bifunctional catalyst and an acid function like SO42−-ZrO2 but their operation is limited if high temperatures in air or H2 are necessary for activation.Fil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Pieck, Carlos Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Shimizu, Kiyoyuki. National Institute for Advanced Industrial Science and Technology (AIST); JapónFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Parera, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Synthesis of liquid menthol by hydrogenation of dementholized peppermint oil over Ni catalysts

Hydrogenation of (-)-menthone and (+)-isomenthone was studied at 2.7 MPa and 100 ºC. The objective was to produce a liquid menthol mixture rich in (-)-menthol from dementholized peppermint oil. Ni-based catalysts were tested and compared for this reaction: a) 6 and 12% Ni dispersed into a nonstoichiometric magnesium aluminate (Ni-Mg-Al) with spinel structure; b) Ni-Raney catalyst. Both types of catalysts were active for (-)-menthone and (+)-isomenthone hydrogenation. Lower conversion but higher selectivity to (-)-menthol was obtained with Ni-Mg-Al catalysts. However, they rapidly lost their activity. Instead Ni-Raney catalysts kept its original activity even after several hydrogenation runs

Integration of Solvent Extraction and Non-Catalytic Esterification for the Treatment of Acidic Feedstocks

The possibility of directly feeding the extract of a liquid-liquid extraction unit to a chemical reactor is analyzed. An example of extraction and noncatalytic esterification of naphthenic acids from acid petroleum crudes is used. Methanol is used both as a solvent and as a reactant. Separate tests of extraction and reaction are performed, and the performance of an integrated process is deduced by computer simulation. Thermodynamic and kinetic parameters for the extraction of naphthenic acids from an acid crude were determined. A partition coefficient of m = 0.66 at 60 °C between the alcoholic and petroleum phases was found. Three successive batch extractions with a 1:1 v/v ratio reduced the acidity from 4.3 to about 1.1 mgKOH g-1. Naphthenic acid concentrates were reacted with supercritical methanol in a batch reactor at high temperatures (280 °C), yielding naphthenic esters. Reaction of 1-2 h with methanol-to-oil molar ratios of 3-6 yielded 92-96% conversion because of a relatively low value of the equilibrium constant. Total conversion could, however, be achieved with the highly diluted extracts. Simulations were run using three countercurrent mixer-settlers and a noncatalytic reactor. The results indicated that extraction/supercritical esterification is a convenient pretreatment step of acidic feedstocks because of its simplicity, the good quality of the deacidified feedstock (acidity <0.5 mgKOH g-1), the total removal of the acids, and the good properties of the ester product as a fuel additive. Characterization of the methyl naphthenate product showed that it had a lower viscosity than the crude or the naphthenic acids; a high flash point; and total miscibility in gasoline, kerosene, and diesel. These and other properties showed that it could be sent to the diesel or fuel oil pools.Fil: Busto, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Torresi, Pablo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Manuale, Débora Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Sustainable fermentation processing of two revalorized agro-industrial discards: carrot and brewer's yeast

An integrated and sustainable fermentation process was developed which enabled both the revalorization of two regional agro-industrial discards as well as by-product reuse. Carrot and brewer's yeast, which are commonly used for animal feed, were processed to obtain 77.5 L of ethanol, 450 kg of solid waste called bagasse, 970 L of liquid effluent called vinasse, and 39.8 kg CO2 per each ton of discarded carrot. Results showed that the obtained bagasse was suitable for feeding 55 animals (calfs). The dilution of vinasse with fresh water (1:5) satisfied the requirements necessary to be used as beverage for the same number of animals, leaving a remnant which could be newly diluted (1:5) and used to irrigate a 0.025-ha carrot crop, the land dimension required to grow 1 ton of carrot.Fil: Aimaretti, Nora Rosa. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Universidad del Centro Educativo Latinoamericano. Facultad de Química; ArgentinaFil: Clementz, Adriana Laura. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Universidad del Centro Educativo Latinoamericano. Facultad de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Codevilla, Agustin. Universidad del Centro Educativo Latinoamericano. Facultad de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rojas, Maria L.. Universidad Nacional de Educacion a Distancia; EspañaFil: Yori, Juan Carlos. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Determinación de propiedades físicas de los suelos en la zona central del municipio del Socorro

In the town of Socorro, Santander primary soil characteristics such as classification, permeability, density and soil strength are unknown, therefore do not have full information to facilitate the sustainable use of this resource. To determine the physical characteristics of a collection of primary data information,taking georeferenced sampling points, then six samples were taken at each point a soil sample for classification, field permeability, density and soil strength was made was made to 0.65 and 1.15 meters. Three types of soils were presented, well graded sands representing 67% of the samples if Border 25% and 8% poorly graded sands, for samples five six permeability was low and the remaining are in the middle level according to darcy classification. The sample with the lowest density was 1.62 g/cm3 was sometimes as filler, the highest density was close to the theoretical 1.99 to 2 g/cm3 g/cm3. The floors of the downtown area of relief mainly fall well graded sands, with greater than 78% moisture, soils are classified as medium permeability and density is in a range of 1.62 to 1.99 g/cm3 varying by the amount of debris in the sample of 14.86% strength really low, high correlation as 89.55% was obtained.En el municipio del Socorro, Santander se desconocen las características primarias del suelo (clasificación, permeabilidad, densidad y resistencia del suelo), por lo tanto no se cuenta con la información completa que facilite el aprovechamiento sustentable de este recurso. Para determinar las características primarias se realizó una recopilación de información de los datos, tomando puntos de muestreo georeferenciados, tomando seis muestras. En cada punto una muestra de suelo para su clasificación, en campo se tomó permeabilidad, densidad y resistencia del suelo a 0.65 y 1,15 metros de profundidad. En el municipio del Socorro, presentaron tres tipos de suelos, arenas bien graduadas representando el 67% de las muestras, para el caso de frontera 25% y 8% arenas mal graduadas. La muestra con menor densidad fue de 1,62 g/cm3 ya que en ocasiones era material de relleno y la mayor densidad fue 1,99 g/cm3 cercana a lo teórico de 2 g/cm3. Los suelos de la zona centro del socorro están comprendidos principalmente por arenas bien graduadas, con humedad superior al 78%, los suelos se clasifican de permeabilidad media según darcy y la densidad se encuentra en un rango de 1,62 hasta 1,99 g/cm3 variando por la cantidad de escombro en la muestra, se obtuvo una resistencia de 14,86% de correlación realmente baja, como también alta de 89,55%