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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.
1

Recuperação de energia na destilação do sistema etanol-agua

Ravagnani, Teresa Massako Kakuta, 1957- 17 July 2018 (has links)
Orientador: João A. F. da Rocha Pereira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas / Made available in DSpace on 2018-07-17T01:08:18Z (GMT). No. of bitstreams: 1 Ravagnani_TeresaMassakoKakuta_M.pdf: 4382701 bytes, checksum: 5b8416905c7161abd154e0e37e995aee (MD5) Previous issue date: 1983 / Resumo: A recompressão de vapor tem sido indicada como sendo uma das alternativas mais promissoras para a recuperação da energia. A aplicação da técnica da recompressão direta de vapor em colunas de destilação é geralmente viável para sistemas que apresentam um destilado com alto calor latente e um baixo gradiente de temperatura ao longo da coluna. No entanto, para misturas em que este comportamento não e verificado, um estudo mais complexo e requerido. O presente trabalho tem como objetivo estudar exaustivamente a utilização da recompressão direta do sistema etanol-água, onde a produto obtido é o álcool azeotrópico. Na simulação da operação da coluna convencional empregou-se o método de UNIQUAC para a predição do equilíbrio líquido-vapor e o método de Newton-Raphson para a resolução do sistema de balanço de massa, energia e equilíbrio de fases. Nestes cálculos, admitiu-se uma eficiência de Murphree de 70% nos pratos. Aplicou-se também um método para a otimização do número de pratos, que fornece o menor numero de estágios para alcançar a mesma separação, a uma dada condição de operação. Através dos resultados obtidos da coluna convensional, realizou-se cálculo da recompressão, utilizando-se um compressor do tipo politrópico, e um procedimento para a minimização da pressão de descarga. Analisou-se o efeito causado pela temperatura e composição da alimentação, razão de refluxo e eficiência politrópica do compressor sobre a energia recuperada. Verificou-se que se obtém níveis de recuperação de energia cerca de 70 a 80% para diversas condições de operação. Realizou-se também, corno estudo complementar a análise da influencia causada pela introdução de um gás inerte no ciclo de recompressão sobre a recuperação de energia. Pelos resultados, observou-se que a introdução do nitrogênio pode causar a redução da razão de compressão, no entanto, com a utilização de quantidades de N2 superiores a 200%, a aplicação da técnica de recompressão não será vantajosa em relação a destilação convencional. / Abstract: Energy recovery is now days one the most important tasks that chemical engineeries face, specially when distillation is involved. Between the energy recovery techniques to be applied to distillation columns, vapour recompression has been pointed out as one of the most promissing. The application of this technique has been discussed in the literature and recomended for distillation systems with high latent heat of vaporization and presenting a low temperature profile across the column, although no detailed work has been published related with the operational conditions of distillation columns. Hence, the present work undertaken study the application of the heat-pump principles to the distillation of the ethanol-water system, obtaining the azeotrope under various operational conditions, as this systems thus not fallows the above recomendations. In order to compare energy recovery of distillation columns using the direct vapour recompression conventional distillation columns were simulated, using the Newton-Raphson generalized method together with the block tridiagonalization of Jacobian matrix. Equilibrium data was obtained using the UNIQUAC method, and a constant Murphree efficiency of 70% was assumed for all the distillation trays. The simulation included a minimization procedure technique for the total number of trays required to obtain the azeotrope, for each one of the operational conditions of the column. The results obtained from the conventional column simulation requeriments for the direct recompression technique, using polytropic compressors were the discharge pressure was minimized during the calculations. The effects of column feed temperature and composition, reflux ratio and polytropic efficiency of the compressor upon energy recovery are analysed. The results show that the use of vapour recompression to distillation of ethanol-water appear to be a good alternative to conventional distillation as energy recovery between 70 to 80% is obtained, specially when feed composition and temperature are low. The work WJS extended to the case when an inert gas (N2) is introduced in the recompression circuit. The results show that an increase in compressed, causes a decrease in the compression ratio, although nitrogene should be added only in quantities up to 200%, as higher amounts of nitrogene lead to low energy recovery. / Mestrado / Mestre em Engenharia Química
2

A window into contemporary Japanese society from a woman's perspective : Taigan no Kanojo (Woman on the Other Bank, 2004) by Kakuta Mitsuyo : a thesis submitted in partial fulfillment [i.e. fulfilment] of the requirements for the degree of Master of Arts in Japanese in the University of Canterbury /

Kennedy, Olivia. January 2008 (has links)
Thesis (M.A.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 175-192). Also available via the World Wide Web.
3

A Window into Contemporary Japanese Society From a Woman’s Perspective: Taigan no Kanojo (Woman on the Other Bank, 2004) By Kakuta Mitsuyo

Kennedy, Olivia January 2009 (has links)
This thesis is an exploration of the novel Taigan no Kanojo (Woman on the Other Bank, 2004) by Japanese writer Kakuta Mitsuyo (1967- ). A biography of the author is presented first, covering Kakuta’s writing to date and the personal circumstances that have influenced her body of work. To my knowledge this is the first in-depth biography prepared, in English or Japanese, of Kakuta Mitsuyo. The next section of this thesis is a discussion of the text. Kakuta is deeply critical of the status of women in Japanese society, and uses Taigan no Kanojo as a platform to make her readers aware of her views. She probes employment conventions that limit women’s choices and the difficulties that women face when they try to combine motherhood with work outside the home. She asks her reader to reconsider what should define ‘success’ or ‘failure’ in terms of women’s lives. This section, therefore, explores these themes, and places the novel firmly within its social background. Lastly, in order to make the novel that forms the focus of this thesis accessible to a non-Japanese readership, translations of Chapters One and 15, and synopses of Chapters Two through 14 are then provided.

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