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Estudio de la actividad del catalizador circulante en la unidad de craqueo catalítico fluidizado (FCC) de la Refinería Estatal Esmeraldas (REE)
Get PDFIn the oil industry the fluidized catalytic cracking unit (FCCU) aims to increase the yield of gasoline production and improve efficiency in the processing of crude oil. The determination of the circulating catalyst activity is a very important parameter, which evaluates the performance of the catalyst. It is also helpful to quantify the amount of fresh catalyst that must be added in the process in order to maintain the activity constant (equilibrium).
The Esmeraldas State Refinery (REE) does not have the necessary infrastructure for the reliably selection and characterization of catalytic behavior. Therefore, this thesis proposes the design and construction of a Test Catalyst Equipment (TCE) for fluidized bed reactions. The work consists of the theoretical design considerations for the manufacture of a laboratory reactor. Subsequently, the real size of reactor is calculated based on the fluidization experiments by ejection.
Additionally, in order to find a potential catalyst for large molecules a meso-porous solid (MMP) is synthesized. Such material is made from of amorphous alumino-silicate, which is subjected to a partial crystallization process of zeolite ZSM-5 in order to increase their activity. The used method is hydrothermal synthesis, i.e. self-generated pressure from water in a closed reactor.
The catalyst equilibrium activity of the three samples taken from FCC Unit of Esmeraldas Refinery evaluated in the TCE indicated an activity of 81%, 79% and 78%. Meanwhile, MMP synthesized catalyst material has an activity of 64%, with a comparable composition gaseous of the product to the commercial catalyst used at the refinery, supplied by Grace Davison Company.En la industria del petróleo la unidad de craqueo catalítico fluidizado (FCCU) tiene como propósito incrementar el rendimiento en la producción de gasolinas así como mejorar la eficiencia en la transformación del crudo. La determinación de la actividad del catalizador que circula en una unidad de craqueo catalítico fluidizado es un parámetro de gran importancia, que permite evaluar el comportamiento del catalizador. Además es de ayuda para cuantificar la cantidad de catalizador fresco que se debe adicionar en el proceso con el objeto de mantener la actividad en equilibrio.
Siendo que la Refinería Estatal de Esmeraldas (REE) no dispone de la infraestructura necesaria para el proceso de selección y caracterización del comportamiento catalítico de manera confiable, la presente tesis propone el diseño y construcción de un equipo para prueba de catalizadores en lecho fluidizado (Testing Catalyst Equipment, TCE). El trabajo consiste en realizar las consideraciones teóricas de diseño para la fabricación de un reactor a nivel de laboratorio. Posteriormente, y tomando como base la experimentación de fluidización por eyección; se obtienen datos que permiten calcular las dimensiones reales del reactor.
Adicionalmente, con el fin de encontrar un potencial catalizador para moléculas grandes, se sintetiza un sólido meso-poroso (MMP). Dicho material está formado a partir de una base de alumino-silicato amorfo, el cual se somete a un proceso de cristalización parcial de zeolita ZSM-5 con el objeto de aumentar su actividad. El método de síntesis utilizado es el hidrotermal, es decir, bajo presión autogenerada a partir de agua en un reactor cerrado.
La actividad del catalizador de equilibrio de las tres muestras tomadas de la unidad FCC en la Refinería Estatal Esmeraldas evaluadas en el TCE indica una actividad de 81%, 79% y 78%. Entre tanto, el material MMP sintetizado como catalizador presenta una actividad del 64 %, con una composición gaseosa comparable a la obtenida con el catalizador comercial, suministrado por la Grace Davison Company, utilizado en refinería
Catalytic performance of silica-aluminas synthesised with the help of chitosan biopolymer
Get PDFMesoporous amorphous silica-aluminas were synthesised with standard aluminium and silicon sources by means of the formation of inorganic-organic composites with the addition of chitosan biopolymer, and compared to analogous catalysts synthesised conventionally. Some catalysts were subjected to hydrothermal treatment. The resulting specific surface areas were from 480 to 573 m2/g in the untreated samples and 300-430 m2/g in the hydrotreated catalysts, average pore sizes ranging from 32 to 100 Å with sharp, unimodal distributions. The chitosan materials showed higher specific surface areas and larger pore sizes than those of their non-chitosan counterparts. The most important differences in the acidic properties were in the relationships between tetrahedral and octahedral aluminium atoms, the chitosan materials having higher relative amounts of tetrahedral aluminium than the conventional silica-aluminas. Evidences of stabilization in the physical and chemical properties were observed in the chitosan-containing catalysts. The catalytic performance was evaluated with the conversion of tri-isopropylbenzene at 400 °C, to assess activity and accessibility, and cyclohexene at 300 °C, to assess hydrogen transfer properties. The highest activity and accessibility was observed in the hydrotreated, chitosan-containing catalyst, while hydrogen transfer capabilities were similar to those of medium unit cell sizes, equilibrium commercial FCC catalysts.Fil: Falco, Marisa Guadalupe. 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: Retuert, Jaime. Universidad de Chile; ChileFil: Hidrobo, Alexis. Universidad de Chile; ChileFil: Covarrubias, Cristian. Universidad de Chile; ChileFil: Araya, Paulo. Universidad de Chile; ChileFil: Sedran, Ulises Anselmo. 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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