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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.
21

Simula??o de reservat?rios n?o convencionais para armazenamento de g?s natural veicular

Vilhena, John Edward Neira 04 June 2004 (has links)
Made available in DSpace on 2014-12-17T14:57:46Z (GMT). No. of bitstreams: 1 JohnENV.pdf: 2614116 bytes, checksum: 0c3230c680d60ac346167f3aa79669e3 (MD5) Previous issue date: 2004-06-04 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The investigation of viability to use containers for Natural Gas Vehicle (NGV) storage, with different geometries of commercial standards, come from necessity to join the ambient, financial and technological benefits offered by the gas combustion, to the convenience of not modify the original proposal of the automobile. The use of these current cylindrical models for storage in the converted vehicles is justified by the excellent behavior that this geometry presents about the imposed tensions for the high pressure that the related reservoirs are submitted. However, recent research directed toward application of adsorbent materials in the natural gas reservoirs had proven a substantial redusction of pressure and, consequently, a relief of the tensions in the reservoirs. However, this study considers alternative geometries for NGV reservoirs, searching the minimization of dimensions and weight, remaining capacity to resist the tensions imposed by the new pressure situation. The proposed reservoirs parameters are calculated through a mathematical study of the internal pressure according to Brazilian standards (NBR) for pressure vessels. Finally simulations of the new geometries behavior are carried through using a commercially avaible Finite Element Method (FEM) software package ALGOR? to verify of the reservoirs efficincy under the gas pressure load / A investiga??o da viabilidade de se utilizar recipientes para armazenamento de g?s natural veicular (GNV), com geometrias diferentes dos padr?es comerciais, parte da necessidade de se aliar os benef?cios ambientais, financeiros e tecnol?gicos oferecidos pela combust?o do g?s, ? conveni?ncia de n?o se alterar a proposta original do autom?vel. O uso dos atuais modelos cil?ndricos para estocagem nos ve?culos convertidos justifica-se pelo excelente comportamento que essa geometria apresenta diante das tens?es provocadas pela alta press?o a que os referidos reservat?rios est?o submetidos. Entretanto, recentes pesquisas, voltadas para aplica??o de materiais adsorventes nos reservat?rios de g?s natural, comprovaram uma substancial redu??o de press?o e, consequentemente, um al?vio das tens?es nos reservat?rios. Diante desse contexto, este estudo prop?e geometrias alternativas para os reservat?rios de GNV buscando a minimiza??o das dimens?es e do peso, mantendo-se, por?m, a capacidade de resistir ?s tens?es impostas pela nova situa??o de press?o. Todos os par?metros geom?tricos dos reservat?rios propostos s?o calculados realizando o estudo matem?tico das tens?es internas de trabalho tomando como base ? norma brasileira (NBR). Por ?ltimo s?o realizadas simula??es do comportamento das novas geometrias fazendo uso do software comercial ALGOR? o qual se baseia no M?todo dos Elementos Finitos (MEF), para realizar a comprova??o da efici?ncia dos reservat?rios sob a press?o imposta pelo g?s
22

Estudo do desempenho de resinas polim?ricas para remo??o de H2S do g?s natural

Silveira, Valdelice Rodrigues da 11 July 2007 (has links)
Made available in DSpace on 2014-12-17T15:42:26Z (GMT). No. of bitstreams: 1 ValdeliceRS.pdf: 981957 bytes, checksum: cedb4f2ae440069c889ba97e29744a20 (MD5) Previous issue date: 2007-07-11 / The natural gas (NG) is a clean energy source and found in the underground of porous rocks, associated or not to oil. Its basic composition includes methane, ethane, propane and other components, like carbon dioxide, nitrogen, hydrogen sulphide and water. H2S is one of the natural pollutants of the natural gas. It is considered critical concerning corrosion. Its presence depends on origin, as well as of the process used in the gas treatment. It can cause problems in the tubing materials and final applications of the NG. The Ag?ncia Nacional do Petr?leo sets out that the maximum concentration of H2S in the natural gas, originally national or imported, commercialized in Brazil must contain 10 -15 mg/cm3. In the Processing Units of Natural Gas, there are used different methods in the removal of H2S, for instance, adsorption towers filled with activated coal, zeolites and sulfatreat (solid, dry, granular and based on iron oxide). In this work, ion exchange resins were used as adsorbing materials. The resins were characterized by thermo gravimetric analysis, infrared spectroscopy and sweeping electronic microscopy. The adsorption tests were performed in a system linked to a gas-powered chromatograph. The present H2S in the exit of this system was monitored by a photometrical detector of pulsing flame. The electronic microscopy analyzes showed that the topography and morphology of the resins favor the adsorption process. Some characteristics were found such as, macro behavior, particles of variable sizes, spherical geometries, without the visualization of any pores in the surface. The infrared specters presented the main frequencies of vibration associated to the functional group of the amines and polymeric matrixes. When the resins are compared with sulfatreat, under the same experimental conditions, they showed a similar performance in retention times and adsorption capacities, making them competitive ones for the desulphurization process of the natural gas / O g?s natural (GN) ? uma fonte de energia limpa encontrada no subsolo de rochas porosas, associado ou n?o ao petr?leo. Sua composi??o b?sica inclui metano, etano, propano e outros componentes, como di?xido de carbono, nitrog?nio, ?cido sulf?drico e ?gua. H2S ? um dos poluentes naturais do g?s natural. ? considerado cr?tico no que se refere ? corros?o. Sua presen?a depende da origem, bem como do processo usado no tratamento do g?s. Ele pode acarretar problemas nas tubula??es e aplica??es finais do GN. A Ag?ncia Nacional de Petr?leo estabelece que a concentra??o m?xima de H2S no g?s natural, de origem nacional ou importado, comercializado no Brasil contenha no m?ximo 10 15 mg/m3. Nas Unidades de Processamento do G?s Natutal, diferentes m?todos s?o usados na remo??o de H2S, por exemplo, em torres de adsor??o recheadas com carv?o ativo, ze?litas e Sulfatreat (s?lido, seco, granular e baseado em ?xido de ferro). Neste trabalho, resinas de troca-i?nica foram usadas como material adsorvente. As resinas foram caracterizadas por an?lise termogravim?trica, espectroscopia de infravermelho e microscopia eletr?nica de varredura. Os ensaios de adsor??o foram realizados em um sistema acoplado a um cromat?grafo a g?s. O H2S presente na sa?da do sistema foi monitorado por um detector fotom?trico de chama pulsante. As an?lises de microscopia eletr?nica demonstraram que a topografia e morfologia das resinas favorecem o processo de adsor??o. Caracter?sticas como comportamento macro, part?culas de tamanhos variados, geometrias esf?ricas, sem a visualiza??o de poros na superf?cie, foram encontrados. Os espectros de infravermelho apresentaram as principais freq??ncias de vibra??o associadas aos grupos funcionais das aminas e matrizes polim?ricas. Quando comparadas ao sulfatreat, sob as mesmas condi??es experimentais, as resinas demonstraram semelhante desempenho em tempos de reten??o e capacidade de adsor??o, tornando-se competitiva para o processo de dessulfuriza??o do g?s natural
23

Estudo do desempenho de resinas polim?ricas para remo??o de H2S do g?s natural

Silveira, Valdelice Rodrigues da 11 July 2006 (has links)
Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 ValdeliceRS.pdf: 629576 bytes, checksum: 6bcf4a0b805ce82618289068cfb23b77 (MD5) Previous issue date: 2006-07-11 / The natural gas (NG) is a clean energy source and found in the underground of porous rocks, associated or not to oil. Its basic composition includes methane, ethane, propane and other components, like carbon dioxide, nitrogen, hydrogen sulphide and water. H2S is one of the natural pollutants of the natural gas. It is considered critical concerning corrosion. Its presence depends on origin, as well as of the process used in the gas treatment. It can cause problems in the tubing materials and final applications of the NG. The Ag?ncia Nacional do Petr?leo sets out that the maximum concentration of H2S in the natural gas, originally national or imported, commercialized in Brazil must contain 10 -15 mg/cm3. In the Processing Units of Natural Gas, there are used different methods in the removal of H2S, for instance, adsorption towers filled with activated coal, zeolites and sulfatreat (solid, dry, granular and based on iron oxide). In this work, ion exchange resins were used as adsorbing materials. The resins were characterized by thermo gravimetric analysis, infrared spectroscopy and sweeping electronic microscopy. The adsorption tests were performed in a system linked to a gas-powered chromatograph. The present H2S in the exit of this system was monitored by a photometrical detector of pulsing flame. The electronic microscopy analyzes showed that the topography and morphology of the resins favor the adsorption process. Some characteristics were found such as, macro behavior, particles of variable sizes, spherical geometries, without the visualization of any pores in the surface. The infrared specters presented the main frequencies of vibration associated to the functional group of the amines and polymeric matrixes. When the resins are compared with sulfatreat, under the same experimental conditions, they showed a similar performance in retention times and adsorption capacities, making them competitive ones for the desulphurization process of the natural gas / O g?s natural (GN) ? uma fonte de energia limpa encontrada no subsolo de rochas porosas, associado ou n?o ao petr?leo. Sua composi??o b?sica inclui metano, etano, propano e outros componentes, como di?xido de carbono, nitrog?nio, ?cido sulf?drico e ?gua. H2S ? um dos poluentes naturais do g?s natural. ? considerado cr?tico no que se refere ? corros?o. Sua presen?a depende da origem, bem como do processo usado no tratamento do g?s. Ele pode acarretar problemas nas tubula??es e aplica??es finais do GN. A Ag?ncia Nacional de Petr?leo estabelece que a concentra??o m?xima de H2S no g?s natural, de origem nacional ou importado, comercializado no Brasil contenha no m?ximo 10 15 mg/m3. Nas Unidades de Processamento do G?s Natutal, diferentes m?todos s?o usados na remo??o de H2S, por exemplo, em torres de adsor??o recheadas com carv?o ativo, ze?litas e Sulfatreat (s?lido, seco, granular e baseado em ?xido de ferro). Neste trabalho, resinas de troca-i?nica foram usadas como material adsorvente. As resinas foram caracterizadas por an?lise termogravim?trica, espectroscopia de infravermelho e microscopia eletr?nica de varredura. Os ensaios de adsor??o foram realizados em um sistema acoplado a um cromat?grafo a g?s. O H2S presente na sa?da do sistema foi monitorado por um detector fotom?trico de chama pulsante. As an?lises de microscopia eletr?nica demonstraram que a topografia e morfologia das resinas favorecem o processo de adsor??o. Caracter?sticas como comportamento macro, part?culas de tamanhos variados, geometrias esf?ricas, sem a visualiza??o de poros na superf?cie, foram encontrados. Os espectros de infravermelho apresentaram as principais freq??ncias de vibra??o associadas aos grupos funcionais das aminas e matrizes polim?ricas. Quando comparadas ao sulfatreat, sob as mesmas condi??es experimentais, as resinas demonstraram semelhante desempenho em tempos de reten??o e capacidade de adsor??o, tornando-se competitiva para o processo de dessulfuriza??o do g?s natural
24

Adsor??o de compostos sulfurados do g?s natural por diferentes adsorventes e dessor??o utilizando CO2 supercr?tico / Adsorption of sulfur compounds from natural gas by different adsorbents and desorption using supercritical CO2

AGUIAR, Melise Ferreira 12 December 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-09T20:05:40Z No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) / Made available in DSpace on 2017-05-09T20:05:40Z (GMT). No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Previous issue date: 2016-12-12 / CAPES / Natural gas is extensively used in industries as well as in other sectors as an energy resource and, sometimes, it needs to undergo processes for the removal of impurities present in its composition. Among them are the sulfur compounds, which can cause damages to pipes and catalysts, making it necessary to develop and/or improve deep desulfurization methods. In this context, granular activated carbon was modified through two methods, oxidation using nitric acid, and impregnation using a ferric chloride solution. The resulting adsorbents were evaluated for their capacity of adsorbing seven sulfur compounds present in the synthetic natural gas sample, through their rupture curves. Afterwards, the adsorbents desorption was performed by using supercritical carbon dioxide under the conditions of 60?C at 100 bar, 150 bar and 200 bar. The results indicate that all the modification methods improved the sulfur compounds retention when compared to virgin activated carbon. The compound that had the greatest increase in the adsorption capacity after iron impregnation was the tert-butyl mercaptan (TBM), and with the activated carbon oxidized by HNO3 it was the dimethyl sulfide (DMS). Nevertheless, the supercritical conditions studied in the desorption stage were efficient only for the unmodified activated carbon. The adsorption capacities of both modified adsorbents after the regeneration were inferior to those capacities obtained in the first adsorption, then two hypotheses were investigated: (1) destruction of the newly created sites after regeneration; and (2) incomplete desorption in the studied supercritical conditions. Through other experiments it was proved that, after regeneration, there was no destruction of the newly created sites; therefore, further studies on the operating conditions are required in order to the modified adsorbents to achieve high regeneration capacities. / O g?s natural ? utilizado nas ind?strias e em outros setores como fonte de energia e necessita, por vezes, de processos de remo??o das impurezas presentes em sua composi??o. Dentre elas est?o os compostos de enxofre, que provocam danos em tubula??es e catalisadores, sendo necess?rio o desenvolvimento e/ou o aperfei?oamento de m?todos para a dessulfuriza??o profunda. Nesse contexto, um carv?o ativado granular foi modificado por meio de dois m?todos, oxida??o utilizando ?cido n?trico e por impregna??o usando uma solu??o de cloreto de ferro III, os adsorventes resultantes foram avaliados quanto ? sua capacidade para adsorver sete compostos de enxofre presentes em uma amostra de g?s natural sint?tica, atrav?s das curvas de rupturas. Posteriormente, foi realizada a dessor??o dos adsorventes utilizando di?xido de carbono supercr?tico nas condi??es de 60 ?C a 100 bar, 150 bar e 200 bar. Os resultados indicam que todos os m?todos de modifica??o melhoraram a reten??o dos compostos sulfurados individuais em compara??o com o carv?o ativado virgem. O composto que obteve maior aumento da capacidade de adsor??o ap?s a impregna??o com ferro foi o terc-butilmercaptana (TBM), e com o carv?o ativado oxidado pelo HNO3 foi o metiletilsulfeto (DMS). J? as condi??es supercr?ticas estudadas na etapa de dessor??o foram eficientes somente para o carv?o ativado n?o modificado. As capacidades de adsor??o dos dois adsorventes modificados ap?s a regenera??o foram inferiores aos obtidos na primeira adsor??o, ent?o duas hip?teses foram investigadas: (1) destrui??o dos novos s?tios criados ap?s a regenera??o; e (2) dessor??o incompleta nas condi??es supercr?ticas estudadas. Atrav?s de outros experimentos comprovou-se que n?o houve ? destrui??o dos novos s?tios criados ap?s a regenera??o, sendo necess?rio um estudo mais profundo em rela??o ?s condi??es operacionais, a fim de alcan?ar altas capacidades de regenera??o dos adsorventes modificados.
25

Atra??o e reten??o de talentos em empresas de engenharia consultiva no setor de petr?leo e g?s natural da cidade de Natal

Barreto, C?sio Carlos Pereira 04 September 2008 (has links)
Made available in DSpace on 2014-12-17T13:53:17Z (GMT). No. of bitstreams: 1 CasioCPB.pdf: 223119 bytes, checksum: 97c79c2a5739a0243c398cc767f21c7c (MD5) Previous issue date: 2008-09-04 / This study addresses the question of attraction and retention of talent in companies that produce engineering projects in the area of oil and natural gas in the city of Natal. The objectives were to identify the mechanisms that these companies use to attract and retain talented professionals and what the relationship between these practices and performance of these organizations in the market. This is a case study of a qualitative nature which were included in the fullness of companies that work in that class in the capital Potiguar. Have been applied to the managers of these companies structured questionnaires with eleven issues orientativas based on theoretical reference adopted. The research finds that managers understand the word "talent", recognize the importance of the appreciation of its employees and the development of their innate abilities to better organizational performance, much due to the fact they are acting in a market of fierce competition. His companies - though not submit the formal procedures related to the subject in question - have mechanisms that can be characterized as the attraction and retention of talent. The relationships identified in this study are consistent with the results found in other studies and put the information here can serve as the basis for that other managers, including other areas, to reach excellence in their respective industries / O presente estudo aborda a quest?o da atra??o e reten??o de talentos nas empresas que elaboram projetos de engenharia na ?rea de petr?leo e g?s natural na cidade do Natal. Os objetivos foram identificar os mecanismos que essas empresas utilizam para atrair e reter profissionais talentosos e quais as rela??es existentes entre essas pr?ticas e o desempenho das referidas organiza??es no mercado. Trata-se de um estudo de caso de natureza qualitativa no qual foram inclu?das a plenitude das empresas que atuam nesse ramo na capital potiguar. Foram aplicados aos gerentes dessas empresas question?rios estruturados com onze quest?es orientativas fundamentadas no referencial te?rico adotado. A pesquisa constata que os gestores compreendem o termo talento , reconhecem a import?ncia da valoriza??o de seus funcion?rios e do desenvolvimento de suas habilidades inatas para um melhor desempenho organizacional, muito devido ao fato de estarem atuando em um mercado de acirrada competi??o. Suas empresas apesar de n?o apresentarem processos formais relacionados ao tema em quest?o apresentam mecanismos que podem ser caracterizados como de atra??o e reten??o de talentos. As rela??es identificadas neste estudo s?o consistentes com os resultados encontrados em outros trabalhos e as informa??es aqui postas podem servir de base para que demais gestores, inclusive de outras ?reas, consigam atingir a excel?ncia em seus respectivos setores
26

Fator de decis?o na ado??o de um sistema de micro-cogera??o de energia a g?s natural :um estudo em Hot?is tr?s estrelas / Factor of decision to adoption of energy micro-cogeneration sistem by natural gas: a study in hjotels three stars

C?mara, Paulo Roberto da 19 May 2006 (has links)
Made available in DSpace on 2014-12-17T14:53:24Z (GMT). No. of bitstreams: 1 PauloRC_principal.pdf: 1483825 bytes, checksum: 47d66773f4b521df5517f6190c35f1be (MD5) Previous issue date: 2006-05-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The natural gas perform a essential paper, not only in primary sectors of energy, but also in others sectors of economy. The use natural gas will have expansion in Brazil, motivated by governmental decision to increase the participation of this fuel in the Brazilian energy matrix from 4% to 12% up until 2010. in order to reach the objective related to increase the consumption of natural gas in the energy matrix and to propose solutions to attend the electric requirements of heart and refrigeration, using natural gas as primary power plant. This thesis has a main objective to analysis the perception of businessmen of hotel sector about the feasability of investment with micro-cogeneration system by natural gas in their hotel in turistic sector, in Natal/RN. It s show a case for the hotels selected analyzing the actual knowledge of businessmen about alternative of new technology in generation of owner energy. There was make a interview using a standard form researching information about this topic. In this interview has shown 4 (four) canaries for businessmen with different configurations of investment in micro-cogeneration. Two of this canaries uses the project finance like option to make fasible this projects. The resulteis showed who businessmen has insecurity to make decision to put in office alone, or with a local company, and perhaps with a national company to perform for a alternative energy system, justifying, the alone feasability and without information by local businessmen. Apart from that, they are receptive for a option to put in office in micro-cogeneration configured in the settings using project finance / O g?s natural desempenha um papel fundamental, n?o s? no setor de energia prim?ria, mas tamb?m em outros setores da economia. Ele ter? forte expans?o no Brasil, motivado pela decis?o do Governo Federal de aumentar a participa??o desse combust?vel na matriz energ?tica de 4% para 12% at? 2010. Para que isso aconte?a ? de suma import?ncia o investimento em novas tecnologias e inclusive o aprimoramento. Afim de um aumento do consumo do g?s natural, na matriz energ?tica, e propor solu??es que atendam aos requisitos el?tricos, na gera??o de calor e refrigera??o, utilizando g?s natural como fonte de energia prim?ria. Este trabalho tem por objetivo principal analisar a atual percep??o dos empres?rios do setor hoteleiro com rela??o ? viabilidade de investimentos com um sistema de microcogera??o a g?s natural em seus hot?is do setor tur?stico, na cidade de Natal/RN. ? apresentado um estudo de caso para os hot?is selecionados, analisando o atual conhecimento dos empres?rios sobre alternativas de novas tecnologias na gera??o de energia pr?pria. Foi realizada uma entrevista com utiliza??o de um question?rio padr?o, buscando as informa??es relevantes sobre o tema. Nesta entrevista foram apresentados 04 (quatro) cen?rios para os empres?rios, onde foram configuradas diferentes op??es de investimentos em microcogera??o. Dois desses cen?rios utilizam o Project finance como op??o de viabilizar o financiamento dos projetos. Os resultados alcan?ados mostram que os empres?rios t?m inseguran?a na tomada de decis?o para investir sozinho, ou em parceria com uma empresa local, e talvez com uma empresa nacional na execu??o de um sistema alternativo de energia, justificando, a inviabilidade isoladaeafalta de vis?o dos empres?rios locais. Em contrapartida se mostraram receptivos a op??o de investimento em micro-cogera??o configurado nos cen?rios utilizando o Project Finance
27

T?cnicas de intelig?ncia artificial para a gera??o din?mica de set points para uma coluna de destila??o

Ara?jo J?nior, Jos? Medeiros de 23 November 2007 (has links)
Made available in DSpace on 2014-12-17T14:54:59Z (GMT). No. of bitstreams: 1 JoseMAJ.pdf: 711051 bytes, checksum: 6bfbf1b93a8a49314295062e59672543 (MD5) Previous issue date: 2007-11-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Artificial Intelligence techniques are applied to improve performance of a simulated oil distillation system. The chosen system was a debutanizer column. At this process, the feed, which comes to the column, is segmented by heating. The lightest components become steams, by forming the LPG (Liquefied Petroleum Gas). The others components, C5+, continue liquid. In the composition of the LPG, ideally, we have only propane and butanes, but, in practice, there are contaminants, for example, pentanes. The objective of this work is to control pentane amount in LPG, by means of intelligent set points (SP s) determination for PID controllers that are present in original instrumentation (regulatory control) of the column. A fuzzy system will be responsible for adjusting the SP's, driven by the comparison between the molar fraction of the pentane present in the output of the plant (LPG) and the desired amount. However, the molar fraction of pentane is difficult to measure on-line, due to constraints such as: long intervals of measurement, high reliability and low cost. Therefore, an inference system was used, based on a multilayer neural network, to infer the pentane molar fraction through secondary variables of the column. Finally, the results shown that the proposed control system were able to control the value of pentane molar fraction under different operational situations / No presente trabalho, aplicamos t?cnicas de intelig?ncia artificial em um sistema simulado de destila??o de petr?leo, mais especificamente em uma coluna debutanizadora. Nesse processo, o produto que chega ? coluna, conhecido como LGN, ? fracionado por meio de aquecimento. Os componentes mais leves s?o transformados em vapor, que v?o constituir o GLP (G?s Liquefeito de Petr?leo), enquanto as fra??es mais pesadas continuam l?quidas, sendo, comumente, chamadas de C5+. Na composi??o do GLP, idealmente, temos apenas propanos e butanos, por?m, na pr?tica, temos a presen?a de contaminantes, como, por exemplo, pentanos (ipentanos e n-pentanos). O objetivo do trabalho ? regular ? quantidade de pentano presente no GLP, por meio da determina??o inteligente dos sets points (SP) de controladores presentes na instrumenta??o original da coluna. Para isso ? utilizado um sistema fuzzy, que ser? respons?vel por ajustar os valores desses SP s, a partir da compara??o entre a fra??o molar do pentano na sa?da da planta (GLP) e a quantidade desejada. Optou-se por controlar apenas a fra??o molar de i-pentano, por esta ser, normalmente, maior que a fra??o molar do n-pentano, e ainda, devido ao fato de que ambas apresentam din?micas extremamente semelhantes em fun??o das condi??es de opera??o da coluna. Por?m, a fra??o molar de pentano, seja do i-pentano ou n-pentano, ? de dif?cil medi??o on-line devido a limita??es, como: longos intervalos de medi??o, pouca confiabilidade e alto custo. Por essa raz?o, foi utilizado um sistema de infer?ncia, constru?do a partir de uma rede neural de m?ltiplas camadas para inferir o percentual de i-pentano a partir de vari?veis secund?rias da coluna. Os resultados obtidos mostram que o sistema fuzzy conseguiu controlar o valor da fra??o molar do i-pentano para diversas situa??es, mostrando ser um sistema de controle avan?ado vi?vel e com um n?vel satisfat?rio de confiabilidade
28

Software inteligente embarcado aplicado ? corre??o de erro na medi??o de vaz?o em g?s natural

Cagni J?nior, El?i 15 February 2007 (has links)
Made available in DSpace on 2014-12-17T14:55:01Z (GMT). No. of bitstreams: 1 EloiCJ.pdf: 4045636 bytes, checksum: e880bc5df766f908db7bff364ffa3574 (MD5) Previous issue date: 2007-02-15 / This study developed software rotines, in a system made basically from a processor board producer of signs and supervisory, wich main function was correcting the information measured by a turbine gas meter. This correction is based on the use of an intelligent algorithm formed by an artificial neural net. The rotines were implemented in the habitat of the supervisory as well as in the habitat of the DSP and have three main itens: processing, communication and supervision / Este trabalho desenvolveu rotinas de software, em um sistema composto basicamente de placa processadora de sinais (DSP) e supervis?rio, cuja finalidade principal foi corrigir a informa??o medida por um medidor de vaz?o do tipo turbina. Essa corre??o se baseia na utiliza??o de um algoritmo inteligente formado por uma rede neural artificial. As rotinas foram implementadas tanto no ambiente do supervis?rio quanto do DSP e tratam de tr?s ?tens principais: processamento, comunica??o e supervis?o
29

Desempenho de um ve?culo flex em bancada dinamom?trica de chassi

Laranja, Gil Colona 18 December 2010 (has links)
Made available in DSpace on 2014-12-17T14:58:06Z (GMT). No. of bitstreams: 1 GilCL_DISSERT.pdf: 1771464 bytes, checksum: 92ddc93639f74d5c2bbc96617815f7ed (MD5) Previous issue date: 2010-12-18 / Flex-fuel vehicles are equipped with Otto Cycle internal combustion engines and have the capability of functioning with more than one type of fuel, mixed at the same tank and burned in the combustion chamber simultaneously. This sort of motorization is a world pattern due to the scarcity of petroleum, the trade of several types of fuels, technology advances and the restriction imposed to gas emissions to the atmosphere. In Brazil, the Flexfuel vehicles are a reality, specially the ones using fuel with 20 to 25% anhydrous alcohol mixed with gasoline and those that use natural gas or original liquid fuel (gasoline or hydrated ethanol). The Brazilian model Fiat Siena, the object of this present scientific investigation, is equipped with a unique electronic central capable of managing the liquid or gaseous fuels. The purpose of this research was to perform a comparative analysis in terms of performance (in terms of both potency and consumption) of a tetra-fuel vehicle - using a chassis dynamometer, operating with different fuels: common gasoline, premium gasoline, Podium gasoline, ethanol or natural gas. It became necessary to develop a bench of tests and trials procedures, as well as to know the functioning of the electronic management of the vehicle under analysis. The experiments were performed at the automotive laboratory in CTGAS-ER (Center of Gas Technologies and Renewable energies) at the light of Brazilian standard ABNT, NBR 7024: Light on-road vehicles - measurement of fuel consumption. The essay results on specific fuel consumption using common gasoline, premium gasoline and Podium gasoline have shown similar results, both for urban and road driving cycles / Os ve?culos flex s?o equipados com um motor de combust?o interna do ciclo Otto e t?m como caracter?stica a capacidade de funcionar com mais de um tipo de combust?vel, misturados no mesmo tanque e queimados na c?mara de combust?o simultaneamente. Este tipo de motoriza??o ? uma tend?ncia mundial devido ? escassez do petr?leo, a comercializa??o de v?rios tipos de combust?veis, aos avan?os tecnol?gicos dos sistemas de gerenciamento eletr?nico de combust?vel e ?s restri??es as emiss?es de gases poluentes na atmosfera. No Brasil, os ve?culos flex s?o uma realidade, com destaque para os ve?culos alimentados com 20 a 25% do ?lcool anidro misturado com gasolina e os que utilizam g?s natural ou o combust?vel l?quido original (gasolina ou etanol hidratado). O FIAT SIENA TETRAFUEL, objeto da presente investiga??o, ? equipado com uma ?nica central eletr?nica capaz de gerenciar os combust?veis l?quidos ou gasoso. A pesquisa em tela teve como prop?sito a an?lise comparativa de desempenho (pot?ncia e consumo) de um ve?culo tetracombust?vel simulando ciclos de condu??o urbano e de estrada em um dinam?metro de chassi, operando com os combust?veis: gasolina comum (tipo C), gasolina aditivada (tipo C), gasolina Podium (Premium), etanol (AEHC) ou g?s natural (GNV). Foi necess?rio desenvolver bancada de testes e procedimentos de ensaios, como tamb?m conhecer o funcionamento do gerenciamento eletr?nico do ve?culo em quest?o. Os ensaios foram realizados no Laborat?rio do Centro de Tecnologias do G?s e Energias Renov?veis de acordo com a norma ABNT NBR 7024 - Ve?culos rodovi?rios leves Medi??o do consumo de combust?vel. Os resultados dos ensaios de consumo espec?fico com as gasolinas comum, aditivada e Podium resultaram em valores pr?ximos, tanto no ciclo de condu??o urbano como tamb?m no ciclo de condu??o de estrada
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Avalia??o da remo??o de sulfeto de hidrog?nio do g?s natural em uma coluna de absor??o

Silva Filho, Luiz Ferreira da 05 March 2009 (has links)
Made available in DSpace on 2014-12-17T15:01:19Z (GMT). No. of bitstreams: 1 LuizFSF.pdf: 1747527 bytes, checksum: e75c5e8a2575620cc3a29490253bcad6 (MD5) Previous issue date: 2009-03-05 / Natural gas, although basically composed by light hydrocarbons, also presents in its composition gaseous contaminants such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). Hydrogen sulfide, which commonly occurs in oil and gas exploration and production activities, besides being among the gases that are responsible by the acid rain and greenhouse effect, can also cause serious harm to health, leading even to death, and damages to oil and natural gas pipelines. Therefore, the removal of hydrogen sulfide will significantly reduce operational costs and will result in oil with best quality to be sent to refinery, thereby resulting in economical, environmental, and social benefits. These factors highlight the need for the development and improvement of hydrogen sulfide sequestrating agents to be used in the oil industry. Nowadays there are several procedures for hydrogen sulfide removal from natural gas used by the petroleum industry. However, they produce derivatives of amines that are harmful to the distillation towers, form insoluble precipitates that cause pipe clogging and produce wastes of high environmental impact. Therefore, the obtaining of a stable system, in inorganic or organic reaction media, that is able to remove hydrogen sulfide without forming by-products that affect the quality and costs of natural gas processing, transport and distribution is of great importance. In this context, the evaluation of the kinetics of H2S removal is a valuable procedure for the treatment of natural gas and disposal of the byproducts generated by the process. This evaluation was made in an absorption column packed with Raschig ring, where natural gas with H2S passes through a stagnant solution, being the contaminant absorbed by it. The content of H2S in natural gas in column output was monitored by an H2S analyzer. The comparison between the obtained curves and the study of the involved reactions have not only allowed to determine the efficiency and mass transfer controlling step of the involved processes but also make possible to effect a more detailed kinetic study and evaluate the commercial potential of each reagent / O g?s natural, embora seja composto basicamente de hidrocarbonetos leves, apresenta tamb?m em sua composi??o gases contaminantes como o CO2 (Di?xido de carbono) e o H2S (Sulfeto de hidrog?nio). O H2S, que comumente ocorre nas atividades de explora??o e produ??o de ?leo e g?s, al?m de estar entre os respons?veis pela chuva ?cida e pelo efeitoestufa, causa s?rios danos ? sa?de, levando inclusive ? morte, e danifica as tubula??es de transporte do petr?leo e do g?s natural. Por isso, eliminando-se o g?s sulf?drico haver? significativa redu??o dos custos de opera??o e uma melhor qualidade do ?leo destinado ? refinaria, resultando assim num beneficio econ?mico, ambiental e social. Tudo isso demonstra a necessidade do desenvolvimento e aprimoramento de seq?estrantes que removam o sulfeto de hidrog?nio da ind?stria de petr?leo. Atualmente existem v?rios processos para o tratamento do g?s natural utilizados pela ind?stria petrol?fera para remo??o do H2S, no entanto eles produzem derivados de aminas prejudiciais ?s torres de destila??o, precipitados insol?veis que provocam entupimento dos dutos e originam res?duos de grande impacto ambiental. Por isso, a obten??o de um sistema est?vel em meio reacional inorg?nico ou org?nico capaz de remover o g?s sulf?drico sem formar subprodutos que afetem a qualidade e o custo do processamento, transporte e distribui??o do g?s natural ? de grande import?ncia. Nesse contexto a avalia??o da cin?tica de remo??o do H2S surge como um procedimento valioso para o tratamento do g?s natural e destino dos subprodutos do processo. Esta avalia??o foi feita numa coluna de absor??o recheada com an?is de Raschig, por onde o g?s natural contaminado com H2S atravessava uma solu??o estagnada, sendo por esta absorvida. Na sa?da da coluna o teor de H2S no g?s era monitorado por um analisador de H2S. A compara??o das curvas obtidas e o estudo das rea??es permitiram n?o somente determinar a efici?ncia e a etapa controladora da transfer?ncia de massa dos processos envolvidos como tamb?m efetuar um estudo cin?tico mais aprofundado e avaliar o potencial comercial de cada reagente

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