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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação e aplicação dos resultados da curva PEV estendida em sistemas de processamento e refino de frações pesadas de petroleo / Evaluation and application of the extended TBP curves in processing and refining of heavy oil fractions

Cuadros Bohórquez, José Fernando 12 August 2018 (has links)
Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T16:03:46Z (GMT). No. of bitstreams: 1 CuadrosBohorquez_JoseFernando_M.pdf: 955377 bytes, checksum: 373ed9ca95fec71c8fc315f656b0a361 (MD5) Previous issue date: 2008 / Resumo: A extração de petróleo no Brasil produz, em grande parte, petróleos pesados. Este tipo de óleo é de difícil processamento e gera grande quantidade de resíduos provenientes das torres de destilação atmosférica e de vácuo. É necessário fracionar esse tipo de petróleo pesado, com a finalidade de incrementar a produção de frações leves, principalmente o Diesel. A caracterização do petróleo é feita mediante as curvas PEV (Ponto de Ebulição Verdadeiro), através das normas padronizadas ASTM (American Society fot Testing and Materials); porém, a curva de destilação só pode ser obtida mediante as normas ASTM até 565ºC. Uma extensão acima dessa temperatura limite, 565ºC, foi desenvolvida pelo grupo de pesquisa do Laboratório de Desenvolvimento de Processos de Separação (LDPS) e do Laboratório de Otimização, Projeto e Controle Avançado (LOPCA), da Faculdade de Engenharia Química da Universidade Estadual de Campinas (FEQ/ UNICAMP), como apresentado em diversos trabalhos prévios (SBAITE, 2005). A metodologia desta extensão envolve o processo de Destilação Molecular, tornando possível a caracterização de frações pesadas de petróleo acima de 565ºC. A caracterização feita com a extensão da curva PEV (nova curva PEV ou DESTMOL) foi usada nesta dissertação que fez uso do simulador de processos Hysys.Plant®, mediante a geração de pseudocomponentes, para fazer a caracterização da alimentação do sistema no processo de refino. Nesta dissertação, foi desenvolvida uma metodologia de simulação para avaliar as curvas PEV estendidas no esquema de separação após o reator de FCC (Fluid Catalytic Cracking). Nesta unidade, são obtidos diferentes produtos: GLP (Gás Liquefeito de Petróleo), gasolina e diesel. O esquema de separação e um processo complexo, incluindo diferentes correntes de reciclo. Os resultados das simulações de dois tipos de resíduos de petróleo foram comparados com dados industriais, obtendo-se bons resultados. Deste trabalho, foi possível concluir que a avaliação das curvas PEV no sistema de separação após o FCC, depende das condições de projeto e de operação desta unidade, uma vez que para valores da curva PEV na alimentação acima de 550ºC, não ocorre a vaporização de alimentações com óleos mais leves, afetando significativamente a operação da unidade. Depois de fazer comparações entre os dados industriais e os dados da simulação, pode-se concluir que a avaliação deste tipo de análise (Curva PEV estendida) deveria ser feita em outro tipo de unidade, por exemplo o riser de FCC, pois este tem a capacidade de processar frações pesadas de petróleo, que é o que esta sendo representado mediante a curva PEV estendida, em frações mais leves como: gases combustíveis, GLP e nafta de craqueamento, obtidas após sua separação na unidade de fracionamento e recuperação de produtos. / Abstract: The oil extraction in Brazil is predominantly of heavy oil. This type of oil is difficult to process and it produces great quantity of residues from atmospheric and vacuum columns. It is necessary to upgrade such kind of residues in order to increase productivity of light fractions, mainly diesel. Oil characterization is made with the aid of the True Boiling Point (TBP) curve through ASTM standard test methods; however, it is possible to have this curve only until 565 ºC. An extension beyond this temperature limit was developed by this research group and it is presented in previous works in the literature, (SBAITE, 2005). For such purpose, molecular distillation process was used, which uses high vacuum as separating agent. In this sense, extension of the True Boiling Point (TBP) curve was obtained using the molecular distillation process, making possible the characterization of the heavy oil fractions of TBP higher than 565ºC. The characterization made with the extension of the TBP was used in this work in the process simulator Hysys.Plant® by the generation of pseudocomponents for characterizing the systems feeding distillation columns in the refining process. In this work, it was developed a simulation methodology in order to evaluate all the separation sequencing after the FCC (Fluid Catalytic Cracking) reactor, in order to produce different products, like (LPG), gasoline and diesel. A complex configuration characterizes this step of the refining process, including several recycle streams. The simulation results of two types of petroleum residues, Alpha 565C+ and Gamma 545C+ were compared with industrial data, yielding, very good match. From this work, it was possible to conclude that the evaluation of the TBP curves in the FCC separation steps depends on the design conditions of this unit, considering that feed at fractionation temperature above 550 ºC remains in liquid state affecting significantly the fractionator tower operation. These results are new in the open literature. After the comparisons between industrial and simulation results, can be concluded that the evaluation of this type heavy oil analysis should be performed in another unit capable to convert these products, called heavy gasoil in noble products, which can be used in the downstream FCC. This conversion process can be performed in the FCC riser. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
12

The effect of condenser temperature and location on the molecular distillation characteristics of stearic acid

Speight, Charles F. January 1956 (has links)
Numerous findings have indicated that the distance between the evaporator and condenser of the molecular still is not as critical, as far as mean free-path design criteria are concerned, as formerly believed. It had been recommended that studies be made on the present apparatus at Virginia Polytechnic Institute to determine exactly how critical this factor is. The purpose of this investigation was to study the effect of condenser temperature and location on the molecular distillation characteristics of stearic acid, and from this study, determine this relationship of condenser temperature and location to be used in centrifugal molecular still operation. This investigation was accomplished using a magnetically driven centrifugal molecular still with a five-inch rotor and employing the following operating conditions: operating pressure, 24 ± 2 microns of mercury, absolute; feed rate, 60 to 65 milliliters per minute; rotor speed, 1000 ± 50 revolutions per minute; feed-residue temperature differential, 24 ± 1 degrees centigrade; condenser water temperature, 25, 35, and 45 degrees centigrade; condenser locations, 3/4 2-1/2, and 5-3/8 inches from the evaporator; and number of passes of the feed over the rotor per fraction, one. lt was concluded from this investigation that if the Iocation of the condenser did not exceed a mean free-path multiple of three, that the location of the condenser had no effect on the elimination maximum of stearic acid, and the elimination maximum was increased approximately one degree centigrade for every four degrees centigrade decrease in condenser temperature. The elimination maximum was not affected by condenser temperature when the condenser was located in a position with a mean free path multiple of six. / Master of Science

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