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\"O estudo da utilização do gás natural como insumo para a indústria química e petroquímica: modelagem de uma planta gás-química\" / The study of the use of natural gas as a feedstock for the chemical and petrochemical industry: the modeling of a gas-chemical plant.Tatiana Magalhães Gerosa 26 February 2007 (has links)
Este trabalho tem como objetivo apresentar, através da modelagem de uma planta gásquímica e da identificação das tecnologias disponíveis, a versatilidade do uso do gás natural como insumo para a indústria química, visando à produção de metanol, amônia e hidrogênio, a partir da fração metano, bem como na indústria petroquímica a obtenção do eteno através da fração etano. Baseado nas pesquisas de mercado, determinou-se que dentre os produtos a serem obtidos a partir do metano, o metanol é o que apresenta o cenário interno mais crítico. Esta situação é refletida através do contínuo aumento da importação, sem que haja nenhuma sinalização deste déficit ser sanado, através da construção de novas unidades industriais. Por outro lado, o cenário da amônia se mostra estável e, ainda que haja um déficit na produção nacional, a situação atual não se mostra tão crítica, mesmo quando realizada a projeção da demanda até 2030. Analisando-se o cenário petroquímico, em poucos anos a produção de eteno atingirá o seu gargalo, e o maior entrave diagnosticado, para a expansão das centrais produtoras, está relacionado à disponibilidade do insumo. Dentro da abordagem técnica proposta, a modelagem da planta gás-química aponta ser viável concentrar a produção de amônia, metanol e hidrogênio no mesmo pólo e que, para estes produtos, a tecnologia atual encontra-se madura e em estágio avançado. Já a produção de eteno, a partir do etano, não deve estar diretamente vinculada, a princípio, à obtenção dos demais produtos, pelo alto volume de gás natural necessário para liberar a fração de etano ideal para a sustentabilidade do projeto. / This work has as objective to present, through the modeling of a gas-chemical plant and also, through the identification of the current available technologies, the versatility of the use of natural gas as a raw material for the chemical industry, aiming the production of methanol, ammonia and hydrogen, from the fraction methane, as well as in the petrochemical industry, the attainment of ethene from the ethane fraction. Based in a market research, it was determined that amongst the products to be obtained from methane, methanol is the product that presents the most critical internal scenario. This situation is reflected through the continuous increase of the importation; without it there is no signaling that this deficit can be overcome, unless new industrials units are constructed. On the other hand, the ammonia scenario is steady and, despite presenting a deficit in the national production, the current situation does not reveal to very so critical, carried through the projection of the demand up to 2030. Analyzing the petrochemical scene, in a few years the ethene production will reach its pass and the biggest diagnosed impediment is related to the availability of the feedstock. Considering the technique proposal, the modeling of the gas-chemical plant shows the viability of concentrating the production of ammonia, methanol and hydrogen in the same site and that, for these products, the current technologies are mature and very well developed. Already the ethene production, from ethane, does not have to be directly entailed, in principle, to the attainment of the other products, considering the high volume of natural gas necessary to liberate the necessary amount of ethane for the sustainable of the project.
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On-line periodic scheduling of hybrid chemical plants with parallel production lines and shared resourcesSimeonova, Iliyana 28 August 2008 (has links)
This thesis deals with chemical plants constituted by parallel batch-continuous production lines with shared resources.
For such plants, it is highly desirable to have optimal operation schedules which determine the starting times of the various batch processes and the flow rates of the continuous processes in order to maximize the average plant productivity and to have a continuous production without interruptions. This optimization problem is constrained by the limitation of the resources that are shared by the reactors and by the capacities of the various devices that constitute the plant.
Such plants are "hybrid" by nature because they combine both continuous-time dynamics and discrete-event dynamics. The formalism of "Hybrid Automata" is there fore well suited for the design of plant models.
The first contribution of this thesis is the development of a hybrid automaton model of the chemical plant in the Matlab-Simulink-Stateflow environment and its use for the design of an optimal periodic schedule that maximises the plant productivity. Using a sensitivity analysis and the concept of Poincaré; map, it is shown that the optimal schedule is a stable limit cycle of the hybrid system that attracts the system trajectories starting in a wide set of initial conditions.
The optimal periodic schedule is valid under the assumption that the hybrid model is an exact description of the plant. Under perturbations on the plant parameters, it is shown that two types of problems may arise. The first problem is a drift of the hybrid system trajectory which can either lead to a convergence to a new stable sub-optimal schedule or to a resource conflict. The second problem is a risk of overflow or underflow of the output buffer tank. The second contribution of the thesis is the analysis of feedback control strategies to avoid these problems. For the first problem, a control policy based on a model predictive control (MPC) approach is proposed to avoid resource conflicts. The feedback control is run on - line with the hybrid Simulink-Stateflow simulator used as an internal model. For the solution of the second problem, a classical PI control is used. The goal is not only to avoid over- or under-filling of the tank but also to reduce the amplitude of outflow rate variations as much as possible. A methodological analysis for the PI controller tuning is presented in order to achieve an acceptable trade-off between these conflicting objectives.
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Návrh bezpečnostního systému chemického podniku / Design of emergency system for chemical plantHorňáková, Markéta January 2011 (has links)
The aim of this graduation thesis is to bring analysis of safety information systems and their configuration in the relation to the chemical plants. Initially, there are theoreti-cally and generally explained terms, as system, information system and safety system. The second (practical) part depicts the use of information systems in real life. The knowledge of theoretical principles and results of the analysis were used for design of the safety information systems for the chemical plants. Conclusion of practical part evaluates the present status and connection with Integrated Rescue System (IRS). The third part brings the transcription of authentic interviews with staff whose are responsi-ble for safety information system maintenance and its use in chemical plant. Finally, this graduation thesis evaluates the safety information system development for the future as well as of influence EU standards on Czech chemical plants.
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eco-Technoeconomic-Analysis of Steel Manufacturing Off-gas ValorizationDENG, LINGYAN January 2020 (has links)
The steel manufacturing industry is one of the largest emitters of CO2, accounting for upwards of 8.8% of all anthropogenic CO2 emissions. The governments are charging taxes on CO2 emissions, which incentivize the industry to further reduce CO2 emissions. At present, much of the CO2, produced in the steel manufacturing process occurs as a result of coke oven and blast furnace gas by-products. As such, two major strategies have been proposed to reduce steel-manufacturing-related CO2 emissions: producing more electricity via optimized combined cycle power plants (CCPP), and converting off-gas by-products into methanol (CBMeOH). The present research consists of an economic and environmental analysis of the status quo, CCPP, and CBMeOH systems for five locations: Ontario, the USA, Finland, Mexico, and China. The economic analysis considered factors such as carbon tax, electricity price, methanol price, electricity carbon intensity, power purchasing parity, and income tax. In the CCPP process, desulphurization is conducted using ProMax with MDEA as the solvent, while the CBMeOH process uses a membrane to separate the bulk H2S, with organic sulfurs such as thiophene being removed via CO2+steam reforming and middle-temperature removal. The results of the economic analysis revealed the CBMeOH plant to be the most profitable in Ontario, the USA, China, and Mexico, while the CCPP system was shown to be the most profitable in Finland. The environmental analysis was conducted using the TRACI, CML-IA, ReCiPe2016, and IMPACT2002+ tools in SimaPro V9, with the results showing the CBMeOH system to be the most environmentally option in Ontario, Finland, and China, and the CCPP system as the most environmentally friendly option in the USA and Mexico. / Dissertation / Doctor of Philosophy (PhD)
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Pesquisa-ação sobre os fatores de sucesso para implantação e continuidade do uso de cartas de controle estatístico de processo em uma planta química no BrasilSantana Júnior, Manoel Bispo de 14 February 2014 (has links)
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Previous issue date: 2014-02-14 / Statistical process control charts (SPC charts) were created in the 20th century in the United States and since then, they have been used for various purposes in different industries and services. SPC chart utilization was widespread in Japan in the postwar period and its effective use in Brazil occurred from the 90´s. Although several examples of use, there are still some industries where deployment of SPC and its sustained use in shopfloor were not successful. In the chemical industry, its use in the shopfloor is controversial and there is no many studies focused on this industry to explain the factors that can impact the successful implementation of statistical control charts by operational teams. This dissertation aims to investigate, through an action research, which are the critical factors for a successful implementation and sustained use of SPC charts in a chemical. It was performed a literature review to gather studies about success factors to implement SPC chart in industries. Using action research, those critical success factors were tested in practice with operators in the chemical plant of a multinational enterprise located in Brazil. This chemical plant has experimented to implement SPC chart in the past with no success. As a result of the action research, we succeed to implement SPC chart in the industrial unit and reduce variability with savings of US$ 150,000.00 per year energy. SPC chart use was well received by operators and leadership, showing that some success factors are really critical for a correct SPC implementation in a brazilian chemical plant. The results were used to develop a roadmap for SPC, with details about how and when to work each success factor. Afterwards, Roadmap was used in another eight different industrial units of the chemical company, all with success. / As cartas de controle estatístico de processo (cartas CEP) foram criadas no século 20 nos Estados Unidos e desde então vêm sendo usadas para diversas finalidades em diferentes setores da indústria e serviços. Seu uso foi difundido no Japão no pós guerra e no Brasil seu uso efetivo ocorreu a partir da década de 90. Apesar de vários exemplos de uso, ainda há para alguns ramos da indústria o desafio de implantar as cartas CEP no chão de fábrica e manter o seu uso pelas equipes. Nas indústrias químicas, seu uso no chamado chão de fábrica é controverso e são poucos os estudos voltados para esse tipo de indústria que expliquem os fatores que impactam no sucesso da implantação das cartas de controle estatístico. Essa dissertação tem como objetivo, investigar, através de uma pesquisa ação, quais fatores são preponderantes no sucesso da implantação e uso continuado das cartas CEP em uma planta química no Brasil. Foi realizada pesquisa bibliográfica sobre os estudos já realizados em diferentes tipos de indústria e coletados os fatores de sucesso identificados. Em seguida, esses fatores que impactam no sucesso da implantação da carta CEP foram testados na prática em uma planta química de uma empresa multinacional instalada no Brasil há muitos anos e que no passado não teve êxito na adoção das cartas CEP. Como resultado, conseguiu-se implantar as cartas de controle estatístico e se garantir a continuidade da sua utilização pelas equipes operacionais. Na planta química pesquisada, reduziu-se a variabilidade da umidade de um produto na seção de filtração resultando em um ganho de 150 mil dólares por ano em consumo de energia para a empresa. O uso da carta CEP foi bem recebido pelos operadores e lideranças. Os resultados obtidos serviram para elaborar um roteiro de implantação das cartas CEP, que detalha para cada fator de sucesso quais ações práticas devem ser feitas e em qual sequência. O roteiro foi posteriormente utilizado em mais oito pilotos de diferentes unidades industriais da própria empresa pesquisada, todos com sucesso.
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AnÃlise FitoquÃmica de Plantas do CearÃ: potencial farmacolÃgico de Cissus verticillata e composiÃÃo volatil de Myrcia sp / Phytochemical analysis plant CearÃ: pharmacological potential Cissus verticillata and composition of volatile Myrcia sp.Francisco Serra Oliveira Alexandre 18 January 2007 (has links)
Universidade Federal do Cearà / O presente trabalho relata o estudo quÃmico dos constituintes volÃteis das folhas e frutos de Myrcia sp., coletados no municÃpio de Amontada-CE em marÃo de 2005 e a obtenÃÃo de fraÃÃes e substÃncias provenientes do decocto das folhas frescas e do extrato etanÃlico das folhas secas de Cissus verticillata, bem como o estudo concomitante do seu potencial farmacolÃgico como hipoglicemiante atravÃs de testes realizados com a fraÃÃo solÃvel em metanol, fraÃÃo rica em tiramina e com a tiramina, obtidos de C. verticillata. Os Ãleos essenciais de Myrcea sp. foram analisados por cromatografia gÃs-lÃquido acoplada à espectrometria de massa (CGL/EM) e, quantitativamente, atravÃs do uso de CGL acoplada a detector do tipo FID. A anÃlise do Ãleo essencial das folhas de Myrcia sp. (GAOFOLHAS), permitiu a identificaÃÃo de treze componentes: d-elemeno, b-elemeno, trans-cariofileno, a-humuleno, b-chamigreno, germacreno D, b-selineno, a-guaieno, a-selineno, a-Z-bisaboleno, d-cadineno, epi-a-murolol e a-cadinol. O Ãleo essencial dos frutos de Myrcia sp. (GAOFRUTOS) permitiu a identificaÃÃo de onze componentes: d-elemeno, b-elemeno, trans-cariofileno, a-guaieno, a-humuleno, germacreno D, b-selineno, a-selineno, germacreno A, d-cadineno e germacreno B. O estudo fitoquÃmico do decocto de C. verticillata resultou na fraÃÃo rica em tiramina (CVFDSM-F19-24) que apÃs fracionamento cromatogrÃfico permitiu o isolamento da substÃncia tiramina, inÃdita no gÃnero Cissus. Os testes realizados com esta fraÃÃo e com a tiramina, em ratos com diabetes aloxan-induzida, mostraram reduÃÃo na glicemia, colesterol total, triglicÃrides e nÃveis de VLDL e aumento nos nÃveis de HDL. O fracionamento cromatogrÃfico da fraÃÃo hexÃnica, proveniente do extrato etanÃlico das folhas secas de C. verticillata, permitiu o isolamento dos esterÃides, b-sitosterol e b-sitosterol-glicosilado. A caracterizaÃÃo estrutural das substÃncias isoladas de C. verticillata foi realizada atravÃs do uso de tÃcnicas espectroscÃpicas, tais como, infravermelho e RMN de 1H e 13C, incluindo tÃcnicas uni e bidimensionais (HMBC e HMQC), bem como a comparaÃÃo com dados descritos na literatura. / The present work reports on the volatile constituents from leaves and fruits of Myrcia sp. collected in Amontada County-Cearà State, in march/2006. It also reports on the phytochemical analysis of the decoction solution from fresh leaves, and the ethanol extract of dried leaves of Cissus verticillata in a concomitant study of its pharmacological potential as hipoglycemiant. GLC/MS and GLC/FID analysis of the essential oil from leaves (GAOFOLHAS) allowed the identification of 13 components: d-elemene, b-elemene, trans-caryophyllene, a-humulene, b-chamigrene, germacrene D, b-selinene, a-guaiene, a-selinene, a-Z-bisabolene, d-cadinene, epi-a-murolol and a-cadinol, while the essential oil from fruits (GAOFRUTOS) allowed the identification of 11 components: d-elemene, b-elemene, trans-cariophylene, a-guaiene, a-humulene, germacrene D, b-selinene, a-selinene, germacrene A, d-cadinene and germacrene B. The silica-gel chromatography analysis of the decoction solution of fresh leaves of C. verticillata allowed the separation of a fraction rich in tyramine, and from it, pure tyramine. Pharmacological tests on rats with aloxan-induced glycemia with both the tyramine rich fraction and pure tyramine allowed reduction on the glycemia levels, as well as for total cholesterol, triglycerids and VLDL, but HDL increasing. Silica-gel chromatography analyses of the ethanol extract from dried leaves of C. verticillata allowed the isolation of b-sitosterol and its glucoside derivative. Structure determination of all substances of C. verticillata was accomplished by means of spectroscopic techniques such as IR, 1H and 13C NMR, including uni and bi-dimensional pulse sequences (HMBC and HMQC) ad comparison with data from the literature.
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