143 research outputs found
Modelo cinético aplicado a Peroxidación Catalítica en Fase Húmeda de fenol a pH neutro, mediante un catalizador Al/Fe-PILC producido a escala bench.
La presencia de fenoles y pesticidas clorados en fuentes de aguas superficiales y subterráneas se ha convertido recientemente en una gran preocupación ambiental [1]. La Peroxidación Catalítica en Fase Húmeda (PCFH) ha demostrado alta eficiencia en la eliminación de contaminantes [2]; sin embargo, su potencial para ser implementada a escala real no se ha desarrollado plenamente, principalmente porque los mejores resultados obtenidos han sido a pHs bajos (3,0 – 5,0), elevadas temperaturas y en régimen batch. Por tanto, el objetivo de este trabajo consistió en estudiar la influencia de las principales condiciones de reacción sobre la cinética de eliminación del carbono orgánico total (COT) de una agua dopada con fenol a condiciones de pH neutro en un reactor slurry, utilizando un catalizador tipo Al/Fe-PILC producido a escala bench (1,2 kg) a partir de precursores en medio concentrado. Se adoptó la metodología desarrollada por Jing et al. (2003) [3] para encontrar las constantes del modelo
Efecto del escalamiento a 10 kg del catalizador Al/Fe-PILC sobre sus propiedades fisicoquímicas y catalíticas en la degradación de fenol
Durante la última década diferentes estudios han demostrado que las arcillas pilarizadas con el sistema mixto Al/Fe presentan una excelente respuesta catalítica en la degradación de compuestos orgánicos tóxicos disueltos en agua mediante Peroxidación Catalítica en Fase Húmeda (PCFH) [1-3]. Sin embargo,la implementación de ésta tecnología en la descontaminación de aguas a escala real depende fuertemente de la preparación reproducible del catalizador a mayor escala, sin una pérdida significativa de sus propiedades tanto fisicoquímicas como catalíticas.
Este trabajo tiene como objetivo principal determinar el efecto de la preparación del catalizador Al/Fe-PILC en tres diferentes escalas y concentración de sus precursores
10 kg scaled-up preparation of Al/Fe-pillared clay CWPO catalysts from concentrated precursors
In this work, the significant intensification of a bentonite pillaring process was achieved by using a novel
methodological approach, leading to an intercalating Al/Fe mixed oligomeric precursor, around 100 times more concentrated than usually reported. In addition, the intercalating step was achieved directly on the clay with no previous swelling of the mineral being required; this allowed the successful scaled-up preparation of the Al/Fe-PILC, by a factor of one thousand, from the lab (10 g) to the pilot scale (10 kg).
Intercalating solutions prepared under either oncentrated (13 cm3) or diluted (widely reported, 2.0 dm3) conditions for lab-scale preparations were both translucent, displaying similar final pH values (close to 4.0) typical of highly oligomerized Al-pillaring solutions. The clay modified from concentrated precursors at the 10 g scale reached a high basal spacing (18.3 Å) and specific surface area (198 m2 g−1 ) with very comparable fractions of Fe forming truly mixed Al/Fe pillars in comparison to a reference material (H2-TPR analyses). This promoted high performance in the catalytic wet peroxide oxidation of phenol in aqueous solution as a toxic model organic molecule at very mild temperature (25.0 °C ± 1.0 °C) and
pressure (76 kPa), exhibiting the highest catalytic efficiency as a function of both parameters (full conversion of phenol together with 45.2% of TOC mineralization) with low iron leaching using a very low catalyst concentration (0.25 g dm−3). Particle size refining of the starting clay, the speed of stirring and conditions for the final washing of the interlayered precursor are the main factors influencing successful pillaring at scales higher than 1.0 kg
Removal of recalcitrant organic compounds from an industrial complex effluent by heterogeneous Fenton-type treatment
Because of their chemical complexity, industrial chemi-mechanical pulping effluents are evaporated and burned, in spite of the high associated cost involved in these processes. The aim of this study was to remove recalcitrant compounds from this kind of wastewater using a Fenton-type treatment. The main parameters involved in the process and their influence on the results were determined. Homemade catalysts based on CuO, Fe2O3, NiO and ZnO, supported on γ-Al2O3 have been tested for catalytic oxidation, and the CuO/γ- Al2O3 catalysts showed the greatest effect on total organic carbon (TOC) reduction (52.7%). A series of twolevel factorial experiments was subsequently applied to evaluate the most favorable range of conditions for CuO/γ-Al2O3 application. The studied variables were hydrogen peroxide concentration ([H2O2], g/L), active phase content (metal oxide supported on alumina, %), mass of catalyst (metal oxide/alumina system, g), and reaction temperature (°C). The highest reduction of all parameters was obtained at the superior level of all variables with CuO/γ-Al2O3, achieving reductions of chemical oxygen demand (COD) and TOC between 40 and 50%. Increasing catalyst mass did not produce additional benefit. This variable has a significant effect only on the reduction of aromatic compounds. At its low level, reduction in aromatic content exceeded 80%. Color reduction was influenced only by temperature (maximum reduction of 90%)Fil: Covinich, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Felissia, Fernando Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Fenoglio, Rosa Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentin
Propuesta en supply chain management y logística en la empresa Alimentos y Carnicos
Por medio de este trabajo se realiza el Diplomado en Supply Chain Management y Logística correspondiente a la opción de grado del programa de Ingeniería Industrial de la Universidad Nacional Abierta y a Distancia. Para ello se escogió a la empresa Alimentos Cárnicos S.A.S, la cual hace parte del Grupo Nutresa y se dedica a la fabricación, distribución y comercialización de cárnicos y embutidos. Se escoge esta empresa por la facilidad en el acceso a la información y porque la misma cuenta con todos los procesos logísticos necesarios para la consecución del diplomado.
Con la realización de este trabajo se espera obtener las bases para analizar y mejorar los procesos logísticos en cualquier tipo de organización, esto puesto que la rama de la logística hace parte del actuar profesional de la ingeniería industrial.
El trabajo contiene 12 capítulos, los cuales se detallan a continuación
• En el capítulo 1, se realiza la configuración de la red de la empresa. Para ello se realizó la identificación de los proveedores y clientes de la cadena logística, en todos sus niveles; estableciendo el nivel de jerarquía de cada uno. A su vez se elaboró un diagrama de la cadena, donde se observa la estructura horizontal y vertical de la empresa y se muestran los procesos que son administrados, monitoreados y no administrados. Finalmente, se muestra la estructura organizacional de la empresa, identificando las ramas y dependencias.
• En el capítulo 2, se realiza la descripción de los ocho procesos del enfoque estratégico GSCF. Para ello se realizó la descripción de los procesos de: Administración de las Relaciones con el Cliente, Administración del Servicio al Cliente, Administración de la Demanda, Gestión de la Orden, Administración del Flujo Manufactura, Administración de las Relaciones con el Proveedor, Desarrollo y Comercialización de Productos y Administración del Retorno.
• En el capítulo 3, se describen los procesos de enfoque APICS-SCOR dentro de la empresa Alimentos Cárnicos, y como se integran para desarrollar los objetivos planteados por la compañía, tomando como referencia el cumplimiento de cada uno de los procesos dentro de las áreas, zonas o sectores correspondientes. Para ello se realizó la descripción de los procesos de Planeación, Aprovisionamiento, Fabricación, Logística, Devolución y Activación.
• En el capítulo 4 se analizan los diagramas de Flujo de Información, Flujo de Productos y Flujo de Dinero de la organización Alimentos Cárnicos S.A.S.
• En el capítulo 5, se realiza un análisis comparativo de Colombia con otros países de Suramérica, Centroamérica, Norteamérica, Europa, Asia y África.
• En el capítulo 6 se representa, por medio de un cuadro sinóptico el documento “Conpes 3547 Política Nacional Logística”.
• En el capítulo 7, se analiza el concepto The Bullwhip Effect—Exploring Causes and Counter Strategies en la organización Alimentos Cárnicos y se explica cómo sucedería esta situación en la empresa, teniendo en cuenta las siguientes causas: Demand-forecast updating, Order batching, Price fluctuation y Shortage gaming.
• En el capítulo 8, se identifica la forma para realizar los inventarios en la organización y con base a esa información se propone una estrategia de gestión para los inventarios; y se genera respuesta a unos interrogantes sobre: la centralización del inventario, el pronóstico de la demanda y la transferencia de inventario entre almacenes.
• En el capítulo 9, se identifica el Layout actual de la organización y se genera una propuesta de un nuevo Layout, ya que se desea desarrollar un proceso productivo más eficiente y mejorar las condiciones de los trabajadores de la planta de producción.
• En el capítulo 10, se propone una estrategia de aprovisionamiento para la empresa alimentos cárnicos S.A.S., para lograr una mejor selección y evaluación de sus proveedores; de tal manera que pueda apoyar la consecución de los objetivos estratégicos de la misma, como el plan de negocio y estrategia de producción.
• En el capítulo 11, se detallan los procesos logísticos de distribución, identificando a través de mapas conceptuales los beneficios y desventajas de implementar estrategias de DRP y TMS en la empresa Alimentos Cárnicos S.A.S., para la distribución del portafolio que en este momento tiene en el mercado. A su vez se describe de manera detallada los diferentes modos y medios de transporte utilizados por una empresa en sus procesos de aprovisionamiento de materias primas y distribución de su producto terminado.
• En el capítulo 12, se identifican las mega tendencias en Supply Chain Management y Logística por medio de un mapa conceptual y se discuten los factores críticos de éxito que dificultan la implementación de esas mega tendencias, en las empresas colombianas.Through this work, the Diploma in Supply Chain Management and Logistics corresponding to the degree option of the Industrial Engineering program of the National Open and Distance University is carried out. For this, the company Alimentos Cárnicos S.A.S was chosen, which is part of Grupo Nutresa and is dedicated to the manufacture, distribution and marketing of meat and sausages. This company is chosen for the ease of access to information and because it has all the logistical processes necessary to achieve the diploma.
With the completion of this work, it is expected to obtain the bases to analyze and improve the logistics processes in any type of organization, this since the logistics branch is part of the professional act of industrial engineering.
The work contains 12 chapters, which are detailed below
• In Chapter 1, the company network setup is done. For this, the identification of the suppliers and customers of the logistics chain was carried out, at all levels; establishing the hierarchy level of each one. In turn, a chain diagram was drawn up, where the horizontal and vertical structure of the company is observed and the processes that are managed, monitored and unmanaged are shown. Finally, the organizational structure of the company is shown, identifying the branches and dependencies.
• In Chapter 2, the description of the eight processes of the GSCF strategic approach is made. For this, a description of the processes of: Customer Relations Management, Customer Service Management, Demand Management, Order Management, Manufacturing Flow Management, Supplier Relations Management, Development and Product Marketing and Return Administration.
In Chapter 3, the APICS-SCOR approach processes within the Alimentos Cárnicos company are described, and how they are integrated to develop the objectives set by the company, taking as a reference the fulfillment of each of the processes within the areas , zones or corresponding sectors. For this, the description of the Planning, Procurement, Manufacturing, Logistics, Return and Activation processes was carried out.
• In Chapter 4, the Information Flow, Product Flow and Money Flow diagrams of the organization Alimentos Cárnicos S.A.S. are analyzed.
• In Chapter 5, a comparative analysis of Colombia is carried out with other countries in South America, Central America, North America, Europe, Asia and Africa.
• In Chapter 6 the document “Conpes 3547 National Logistics Policy” is represented by means of a synoptic table.
• In Chapter 7, the concept The Bullwhip Effect — Exploring Causes and Counter Strategies in the Alimentos Cárnicos organization is analyzed and it is explained how this situation would happen in the company, taking into account the following causes: Demand-forecast updating, Order batching, Price fluctuation and Shortage gaming.
• In Chapter 8, the way to carry out inventories in the organization is identified and based on this information a management strategy for inventories is proposed; and answers are generated to questions about: inventory centralization, demand forecasting and inventory transfer between warehouses.
In Chapter 9, the current Layout of the organization is identified and a proposal for a new Layout is generated, since it is desired to develop a more efficient production process and improve the conditions of the workers in the production plant.
• In chapter 10, a supply strategy is proposed for the company Alimentos Carne Meat S.A.S., to achieve a better selection and evaluation of its suppliers; in such a way that it can support the achievement of its strategic objectives, such as the business plan and production strategy.
• In Chapter 11, the logistics distribution processes are detailed, identifying through concept maps the benefits and disadvantages of implementing DRP and TMS strategies in the company Alimentos Cárnicos SAS, for the distribution of the portfolio that it currently has in the market. At the same time, the different modes and means of transport used by a company in its processes of sourcing raw materials and distribution of its finished product are described in detail.
• In Chapter 12, mega trends in Supply Chain Management and Logistics are identified by means of a concept map and the critical success factors that hinder the implementation of these mega trends in Colombian companies are discussed
Fenton-like oxidation of Orange II solutions using heterogeneous catalysts based on saponite clay
Fe-clay catalysts have been prepared and tested for Orange II oxidation with H2O2 in aqueous solution. Thereaction is carried out in a batch reactor, using different hydrogen peroxide concentrations, and in a wide range oftemperature and pH values. Twelve samples were prepared, with three different iron loads (7.5, 13.0 and 17.0 %,w/w), and using four iron salts as precursors, namely Fe(II) acetate, Fe(II) oxalate, Fe(II) acetylacetonate and Fe(III)acetylacetonate. The samples were characterized using X-ray diffraction, thermal analysis, infrared spectroscopy andadsorption of nitrogen at 77K. The catalytic results show that these solids present good catalytic properties for thedegradation and mineralization of Orange II solutions, allowing to reach, in the best conditions and after 4h ofoxidation, 99% of dye degradation with 91% of TOC (Total Organic Carbon) reduction (at 70ºC), using only ca. 90 mgof clay catalyst per litre of solution. Nevertheless, 96% of dye removal with 82% of mineralization were also reachedat 30ºC. Besides, the amount of iron released into the final solution is lower than 1 ppm, in the worst of the cases,and 0.09 ppm in the best case
Dyes decolorization using silver nanoparticles supported on nanometric diamond as highly efficient photocatalyst under natural Sunlight irradiation
[EN] Herein we report that silver nanoparticles supported on commercial diamond nanoparticles functionalized with hydroxyl groups (D3) is a cost-effective heterogeneous catalyst for the decolorization of different synthetic dyes (Methylene Blue, Orange II, Acid Red 1 or Rhodamine B) using H2O2 as oxidant under natural Sunlight irradiation. Importantly, the photocatalytic activity of Ag/D3 is higher than that of analogous catalysts based on Ag NPs supported on graphite or activated carbon and similar to that of costly Au/D3 catalyst or the benchmark Ag/TiO2 material. Ag/D3 stability was established by performing consecutive reuses, without observing either decrease of the catalytic activity or metal leaching, while particle size increase occurs in a low extent. Productivity tests allow determining a minimum TON for dyes and H2O2 of about 500 and 6000, respectively. © 2016 Elsevier B.V. All rights reserved. All rights reserved.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, CTQ2012-32315 and CTQ2014-53292-R) is gratefully acknowledged. Generalidad Valenciana is also thanked for funding (Prometeo 2012/013).
European Commission has been gratefully acknowledged for granting Erasmus Mundus Action-2 (SVAAGATA) fellowship to the first author for carrying out this work in Department of Chemistry, Universitat Politecnica de Valencia, Valencia, Spain.Manickam-Periyaraman, P.; Espinosa, SM.; Espinosa-López, JC.; Navalón Oltra, S.; Subramanian, S.; Alvaro Rodríguez, MM.; García Gómez, H. (2016). Dyes decolorization using silver nanoparticles supported on nanometric diamond as highly efficient photocatalyst under natural Sunlight irradiation. Journal of Environmental Chemical Engineering. 4(4):4485-4493. https://doi.org/10.1016/j.jece.2016.10.011S448544934
Heterogeneous advanced photo- Fenton process using peroxymonosulfate and peroxydisulfate in presence of zero valent metallic iron: A comparative study with hydrogen peroxide photo-Fenton process
Photodegradation of Phenol over a Hybrid Organo-Inorganic Material: Iron(II) Hydroxyphosphonoacetate
Water treatment is a hot topic, and it will become much more important in the decades ahead. Advanced oxidation processes are being increasingly used for organic contaminant removal, for example using photo-Fenton reactions. Here we report the use of an organo-inorganic hybrid, Fe[HO3PCH(OH)COO]·2H2O, as Fenton photocatalyst for phenol oxidation with H2O2 under UVA radiation. Preactivation, catalyst content, and particle size parameters have been studied/optimized for increasing phenol mineralization. Upon reaction, iron species are leached from the catalyst making a homogeneous catalysis contribution to the overall phenol photo-oxidation. Under optimized conditions, the mineralization degree was slightly larger than 90% after 80 min of irradiation. Analysis by X-ray photoelectron spectroscopy revealed important chemical modifications occurring on the surface of the catalyst after activation and phenol photodegradation. The sustained slow delivery of iron species upon phenol photoreaction is advantageous as the mixed heterogeneous−homogeneous catalytic processes result in very high phenol mineralization.Proyecto nacional MAT2010-1517
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