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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

Impacto da topologia de integração energética sobre o comportamento dinâmico e controlabilidade de um processo / Impacts of heat integration topology on process dynamics and controllability

Coelho, Filipe Alves, 1989 24 August 2018 (has links)
Orientador: Roger Josef Zemp / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-24T10:53:42Z (GMT). No. of bitstreams: 1 Coelho_FilipeAlves_M.pdf: 2399383 bytes, checksum: b85757c1658e9d740e40d955ddc36d5e (MD5) Previous issue date: 2014 / Resumo: Com o desenvolvimento da análise pinch, foi possível estabelecer metas de consumo de utilidades em processos químicos e posteriormente sintetizar a rede capaz de atender as metas estabelecidas. Em contrapartida, os processos energeticamente integrados atendendo essas metas podem ser difíceis de se controlar e isso motiva estudar a controlabilidade e a dinâmica desses processos. Porém, a literatura vem tratando esses estudos desacoplando a rede do restante do processo e isso pode introduzir erros nos resultados, pois dinâmicas importantes associadas aos reciclos são perdidas. Assim, neste trabalho foi levantada a hipótese de que a análise da controlabilidade de redes de trocadores de calor, assim como o projeto de seus controladores, desprezando-se outros equipamentos de processo como colunas, reatores etc., pode induzir a uma falsa compreensão da dinâmica do processo e levar à síntese de uma rede fora do ótimo entre objetivos econômicos e controlabilidade. Para a execução das simulações, foi construída uma ferramenta computacional em Matlab onde foram implementados os modelos dos trocadores de calor e dos outros equipamentos de processo. Foi proposto um estudo de caso para um processo fictício com cinco topologias de redes de trocadores onde a controlabilidade foi avaliada utilizando-se dois índices em estado estacionário e um índice dinâmico. Observou-se que existe uma tendência de redução na controlabilidade conforme a integração energética aumenta e por isso a topologia que atendia às metas da análise pinch foi indicada por todos os índices como tendo a pior controlabilidade. Também foi testada a influência do atraso de transporte e da diferença entre as velocidades das dinâmicas dos equipamentos. A hipótese levantada neste trabalho foi comprovada / Abstract: The development of pinch analysis gave a powerful tool for engineers to establish energy targets for chemical processes and, with some extra work, synthesize a heat exchanger network to attain those targets. On the other hand, these heat integrated networks are generally hard to control, motivating several studies on their controllability and dynamics. However, most scientific studies decouples the network from the rest of the process and it can introduce errors in the results, because important dynamics related to recycles are lost. Therefore, it was raised the hypothesis that the controllability analysis of a heat exchanger network, as the design of their controllers, disregarding the other process equipments such as columns, reactors etc., may lead to false comprehension of the process dynamics and make the network synthesis out of the optimum between economic and controllability objectives. To simulate the systems, a computational tool was developed in Matlab, where the models of the heat exchangers and the other equipments were implemented. A case study of a fictitious process was proposed and five heat exchanger topologies were synthesized, with controllability assessed by two steady state indexes and a dynamic one. It was observed that controllability decreases as heat integration increases, therefore, the pinch network was pointed as having the worst controllability. The effects of dead time and difference between dynamic velocities in the equipments were also tested. The hypothesis was proven / Mestrado / Engenharia Química / Mestre em Engenharia Química
12

FORMULATION AND USE OF A PERVAPORATION MATHEMATICAL MODEL

kahwaji janho, michel E. 28 May 2015 (has links)
No description available.
13

Modelling and optimisation of oxidative desulphurization process for model sulphur compounds and heavy gas oil : determination of rate of reaction and partition coefficient via pilot plant experiment : modelling of oxidation and solvent extraction processes : heat integration of oxidation process : economic evaluation of the total process

Khalfalla, Hamza Abdulmagid January 2009 (has links)
Heightened concerns for cleaner air and increasingly more stringent regulations on sulphur content in transportation fuels will make desulphurization more and more important. The sulphur problem is becoming more serious in general, particularly for diesel fuels as the regulated sulphur content is getting an order of magnitude lower, while the sulphur contents of crude oils are becoming higher. This thesis aimed to develop a desulphurisation process (based on oxidation followed by extraction) with high efficiency, selectivity and minimum energy consumption leading to minimum environmental impact via laboratory batch experiments, mathematical modelling and optimisation. Deep desulphurization of model sulphur compounds (di-n-butyl sulphide, dimethyl sulfoxide and dibenzothiophene) and heavy gas oils (HGO) derived from Libyan crude oil were conducted. A series of batch experiments were carried out using a small reactor operating at various temperatures (40-100 °C) with hydrogen peroxide (H2O2) as oxidant and formic acid (HCOOH) as catalyst. Kinetic models for the oxidation process are then developed based on 'total sulphur approach'. Extraction of unoxidised and oxidised gas oils was also investigated using methanol, dimethylformamide (DMF) and N-methyl pyrolidone (NMP) as solvents. For each solvent, the 'measures' such as: the partition coefficient (KP), effectiveness factor (Kf) and extractor factor (Ef) are used to select the best/effective solvent and to find the effective heavy gas oil/solvent ratios. A CSTR model is then developed for the process for evaluating viability of the large scale operation. It is noted that while the energy consumption and recovery issues could be ignored for batch experiments these could not be ignored for large scale operation. Large amount of heating is necessary even to carry out the reaction at 30-40 °C, the recovery of which is very important for maximising the profitability of operation and also to minimise environmental impact by reducing net CO2 release. Here the heat integration of the oxidation process is considered to recover most of the external energy input. However, this leads to putting a number of heat exchangers in the oxidation process requiring capital investment. Optimisation problem is formulated using gPROMS modelling tool to optimise some of the design and operating parameters (such as reaction temperature, residence time and splitter ratio) of integrated process while minimising an objective function which is a coupled function of capital and operating costs involving design and operating parameters. Two cases are studied: where (i) HGO and catalyst are fed as one feed stream and (ii) HGO and catalyst are treated as two feed streams. A liquid-liquid extraction model is then developed for the extraction of sulphur compounds from the oxidised heavy gas oil. With the experimentally determined KP multi stage liquid-liquid extraction process is modelled using gPROMS software and the process is simulated for three different solvents at different oil/solvent ratios to select the best solvent, and to obtain the best heavy gas oil to solvent ratio and number of extraction stages to reduce the sulphur content to less than 10 ppm. Finally, an integrated oxidation and extraction steps of ODS process is developed based on the batch experiments and modelling. The recovery of oxidant, catalyst and solvent are considered and preliminary economic analysis for the integrated ODS process is presented.
14

Sunlight Ancient and Modern: the Relative Energy Efficiency of Hydrogen from Coal and Current Biomass

Zhang, Ling 23 August 2004 (has links)
The significance of hydrogen production is increasing as fossil fuels are being depleted and energy security is of increasing importance to the United States. Furthermore, its production offers the potential to alleviate concerns regarding global warming and air pollution. In this thesis we focused on examining the efficiency of hydrogen production from current biomass compared to that from fossil fuel coal. We explored the efficiencies of maximum hydrogen production from biomass and from coal under current technology, namely coal gasification and biomass pyrolysis, together with following-up technologies such as steam reforming (SR). Bio-oil, product from pyrolysis and precursor for steam reforming, is hard to define. We proposed a simulation tool to estimate the pyrolytic bio-oil composition from various biomasses. The results helped us understand the accuracy that is needed for bio-oil composition prediction in the case it is converted to hydrogen. Hydrogen production is energy intensive. Therefore, heat integration is necessary to raise the overall thermodynamic efficiencies for both coal gasification and biomass pyrolysis. The results showed that considering the ultimate energy source, sunlight, about 6-fold more sunlight would be required for the coal to hydrogen than that for biomass to hydrogen. The main difference is in the efficiency of conversion of the ancient biomass to coal and therefore, for modern mankind, this loss has already been incurred.
15

Desenvolvimento de um módulo computacional para integração energética em plantas sucroalcooleiras na plataforma EMSO

Pina, Eduardo Antonio January 2015 (has links)
Orientador: Prof. Dr. Marcelo Modesto / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2015. / Nas últimas décadas, a integração energética tem se desenvolvido em busca do melhor uso da energia e de recursos em processos industriais e consequente redução do consumo de combustíveis fósseis e dos impactos negativos ao meio ambiente. Dentre os métodos de integração energética, o Método Pinch é, sem dúvida, o mais popular devido a sua simplicidade de implementação e eficiência. Os repetitivos cálculos que a metodologia requer levaram ao desenvolvimento de softwares a fim de agilizar e simplificar o trabalho do projetista. No presente trabalho, foi desenvolvida uma ferramenta computacional para realizar a integração energética de correntes pelo Método Pinch que será utilizada como módulo auxiliar ao programa principal do Projeto Temático FAPESP (Processo Fapesp 2012/04179-2) da Biorrefinaria Virtual de 1ª Geração, a ser desenvolvido na plataforma EMSO. A ferramenta foi desenvolvida na forma de um plug-in, o que facilita o seu uso e distribuição entre vários usuários, na linguagem de programação C++ e fornece ao usuário as metas energéticas, subsidiandoo na elaboração da rede preliminar de trocadores de calor e indicando possibilidades de integração entre correntes que demandem utilidades quentes ou frias. A validação da ferramenta se deu por meio de sua aplicação na integração energética de cinco casos de diferentes níveis de complexidade, sendo um voltado à indústria sucroalcooleira. Os resultados obtidos pelo plug-in foram comparados aos encontrados na literatura e aos da consagrada ferramenta Aspen Energy Analyser®, comprovando-se a consistência e eficiência do plug-in, até mesmo para casos mais complexos, como problemas limiares e de múltiplos pontos Pinch. Como o EMSO não oferece suporte à criação de gráficos, uma planilha suporte em Excel® foi desenvolvida a fim de construir as Curvas Compostas e a Grande Curva Composta, funcionando de modo inteiramente automatizado. / Over the last few decades, heat integration has been developed in search for the better use of energy and resources in industrial processes and eventual reduction in fossil fuels consumption and in the negative environmental impacts. Among the heat integration methods, Pinch technology is without a doubt the most popular one due to its implementation simplicity and efficiency. The monotonous calculations it requires have led to the development of computer software to reduce time and simplify the designer¿s work. In the present study, a computational tool was developed for heat integration through Pinch Analysis to be used as an auxiliary module to the main FAPESP Thematic Project (Fapesp process 2012/04179-2) program of the 1st generation virtual biorefinery, which is being developed on EMSO platform. The computational tool was developed in the form of a plug-in, making its use and distribution among several users easier, in the C++ programming language and it supplies the user with the energy targets, aiding him or her with the design of the preliminary heat transfer network and indicating integration possibilities between hot or cold utility requiring streams. The tool validation was carried out through its application in five case studies of different complexity levels, one of them being related to the sugarcane industry. The plug-in¿s results were compared to the ones gathered from the literature and the ones obtained from the well-stablished heat integration tool Aspen Energy and Analyser®, proving the plug-in¿s consistency and efficiency even for more complex cases such as threshold problems and multiple Pinch problems. As EMSO does not support the design of charts like the Composite Curves and the Grand Composite Curve, an Excel® spreadsheet was developed for this purpose, working on an entirely automated way.
16

Potencial de geração de energia elétrica a partir de bagaço e palha de cana-de-acúcar considerando ciclos a vapor com pressões supercríticas

Castrillon, Carolina Lopez January 2017 (has links)
Orientadora: Profa. Dra. Silvia Azucena Nebra de Pérez / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2017. / O Brasil é destaque mundial no uso de energias renováveis, o setor sucroenergético possui papel chave nesta participação, uma vez que somente os produtos da cana-de-açúcar são responsáveis por 16,9% de toda a oferta de energia do país. Este valor já ultrapassa o fornecido pelas usinas hidroelétricas que é de 11,3%. Parte desse aumento é devido à expansão da área plantada de cana, mas o desenvolvimento tecnológico também tem desempenhado um papel importante. Com o aumento da mecanização da colheita de cana de açúcar e a diminuição da prática de queima prévia da palha nos canaviais em função de protocolos ambientais estabelecidos entre os usineiros e o governo, cresce significativamente a quantidade de palha disponível no campo que pode ser aproveitada. No futuro, os ciclos de vapor supercríticos são uma boa alternativa para centrais de cogeração nas usinas de cana-de-açúcar uma vez que eles podem alcançar valores de eficiência maiores em comparação com os ciclos de vapor utilizados atualmente. Já existem no mundo usinas de cogeração como Avedøre II com ciclos a vapor supercríticos que usam biomassa como combustível. Assim, neste trabalho é analisada a utilização na cogeração de 50 % da palha total produzida no campo misturada com bagaço como combustível que ingressaria na caldeira, o outro 50 % da palha total produzida é deixada no campo. A modelagem do processo de geração de energia elétrica foi feita por médio de balanços de massa e energia, assim como de analises exergeticos com diferentes configurações do sistema de cogeração, incluindo as mais comuns nas usinas sucrooalcoleiras, modificação do ciclo Rankine com regeneradores fechados e reaquecimento, assim como a configuração supercrítica com integração energética do processo, destilação duplo efeito e fermentação híbrida com pervaporação. / In this work a heat integration analysis of first-generation ethanol production process was made. An alternative technology for fermentation process was introduced. Hybrid membrane fermentation was considered as a non-conventional operation, this case of intensification process was used to evaluate its impact over the general energy consumption of the integrated process. For heat integration was regarded the cogeneration system, sugarcane juice evaporation, hybrid fermentation with membrane and distillation. The fuel in this cogeneration system is a bagasse-straw sugarcane mixture. The fermentation and distillation mass balances were taken from the literature. The evaporation and cogeneration stages were simulated, using the fermentation and distillation mass balances as inputs parameters. The sugarcane juice evaporation system was optimized based on heat integration analysis results. The heat-exchanger size for the integrated system was determined according to hot and cold utilities needs. An economic analysis was also accomplished in order to estimate the capital and operating costs.
17

Process Integration: Unifying Concepts, Industrial Applications and Software Implementation

Mann, James Gainey 29 October 1999 (has links)
This dissertation is a complete unifying approach to the fundamentals, industrial applications and software implementation of an important branch of process-engineering principles and practice, called process integration. The latter refers to the system-oriented, thermodynamically-based and integrated approaches to the analysis, synthesis and retrofit of process plants, focusing on integrating the use of materials and energy, and minimizing the generation of emissions and wastes. This work extends process integration to include applications for industrial water reuse and wastewater minimization and presents previous developments in a unified manner. The basic ideas of process integration are: (1) to consider first the big picture by looking at the entire manufacturing process as an integrated system; (2) to apply process-engineering principles to key process steps to establish a priori targets for the use of materials and energy, and for the generation of emissions and wastes; and (3) to finalize the details of the process design and retrofit later to support the integrated view, particularly in meeting the established targets. Pinch technology is a set of primarily graphical tools for analyzing a process plant's potential for energy conservation, emission reduction and waste minimization. Here, we identify targets for the minimum consumption of heating and cooling utilities, mass-separating agents, freshwater consumption, wastewater generation and effluent treatment and propose economical grassroots designs and retrofit projects to meet these goals. An emerging alternative approach to pinch technology, especially when analyzing complex water-using operations and effluent-treatment systems, is mathematical optimization. We solve nonlinear programming problems for simple water-using operations through readily available commercial software. However, more complex, nonconvex problems require sophisticated reformulation techniques to guarantee optimality and are the subject of continuing academic and commercial development. This work develops the principles and practice of an environmentally significant breakthrough of process integration, called water-pinch technology. The new technology enables the practicing engineers to maximize water reuse, reduce wastewater generation, and minimize effluent treatment through pinch technology and mathematical optimization. It applies the technology in an industrial water-reuse demonstration project in a petrochemical complex in Taiwan, increasing the average water reuse (and thus reducing the wastewater treatment) in the five manufacturing facilities from 18.6% to 37%. This dissertation presents complete conceptual and software developments to unify the known branches of process integration, such as heat and mass integration, and wastewater minimization, and explores new frontiers of applications to greatly simplify the tools of process integration for practicing engineers. / Ph. D.
18

Modelling and optimisation of oxidative desulphurization process for model sulphur compounds and heavy gas oil. Determination of Rate of Reaction and Partition Coefficient via Pilot Plant Experiment; Modelling of Oxidation and Solvent Extraction Processes; Heat Integration of Oxidation Process; Economic Evaluation of the Total Process.

Khalfalla, Hamza Abdulmagid January 2009 (has links)
Heightened concerns for cleaner air and increasingly more stringent regulations on sulphur content in transportation fuels will make desulphurization more and more important. The sulphur problem is becoming more serious in general, particularly for diesel fuels as the regulated sulphur content is getting an order of magnitude lower, while the sulphur contents of crude oils are becoming higher. This thesis aimed to develop a desulphurisation process (based on oxidation followed by extraction) with high efficiency, selectivity and minimum energy consumption leading to minimum environmental impact via laboratory batch experiments, mathematical modelling and optimisation. Deep desulphurization of model sulphur compounds (di-n-butyl sulphide, dimethyl sulfoxide and dibenzothiophene) and heavy gas oils (HGO) derived from Libyan crude oil were conducted. A series of batch experiments were carried out using a small reactor operating at various temperatures (40 ¿ 100 0C) with hydrogen peroxide (H2O2) as oxidant and formic acid (HCOOH) as catalyst. Kinetic models for the oxidation process are then developed based on `total sulphur approach¿. Extraction of unoxidised and oxidised gas oils was also investigated using methanol, dimethylformamide (DMF) and N-methyl pyrolidone (NMP) as solvents. For each solvent, the `measures¿ such as: the partition coefficient (KP), effectiveness factor (Kf) and extractor factor (Ef) are used to select the best/effective solvent and to find the effective heavy gas oil/solvent ratios. A CSTR model is then developed for the process for evaluating viability of the large scale operation. It is noted that while the energy consumption and recovery issues could be ignored for batch experiments these could not be ignored for large scale operation. Large amount of heating is necessary even to carry out the reaction at 30-40 0C, the recovery of which is very important for maximising the profitability of operation and also to minimise environmental impact by reducing net CO2 release. Here the heat integration of the oxidation process is considered to recover most of the external energy input. However, this leads to putting a number of heat exchangers in the oxidation process requiring capital investment. Optimisation problem is formulated using gPROMS modelling tool to optimise some of the design and operating parameters (such as reaction temperature, residence time and splitter ratio) of integrated process while minimising an objective function which is a coupled function of capital and operating costs involving design and operating parameters. Two cases are studied: where (i) HGO and catalyst are fed as one feed stream and (ii) HGO and catalyst are treated as two feed streams. A liquid-liquid extraction model is then developed for the extraction of sulphur compounds from the oxidised heavy gas oil. With the experimentally determined KP multi stage liquid-liquid extraction process is modelled using gPROMS software and the process is simulated for three different solvents at different oil/solvent ratios to select the best solvent, and to obtain the best heavy gas oil to solvent ratio and number of extraction stages to reduce the sulphur content to less than 10 ppm. Finally, an integrated oxidation and extraction steps of ODS process is developed based on the batch experiments and modelling. The recovery of oxidant, catalyst and solvent are considered and preliminary economic analysis for the integrated ODS process is presented.
19

Kinetic modelling simulation and optimal operation of trickle bed reactor for hydrotreating of crude oil : kinetic parameters estimation of hydrotreating reactions in trickle Bbed reactor (TBR) via pilot plant experiments : optimal design and operation of an industrial TBR with heat integration and economic evaluation

Jarullah, Aysar Talib January 2011 (has links)
Catalytic hydrotreating (HDT) is a mature process technology practiced in the petroleum refining industries to treat oil fractions for the removal of impurities (such as sulfur, nitrogen, metals, asphaltene). Hydrotreating of whole crude oil is a new technology and is regarded as one of the more difficult tasks that have not been reported widely in the literature. In order to obtain useful models for the HDT process that can be confidently applied to reactor design, operation and control, the accurate estimation of kinetic parameters of the relevant reaction scheme are required. This thesis aims to develop a crude oil hydrotreating process (based on hydrotreating of whole crude oil followed by distillation) with high efficiency, selectivity and minimum energy consumption via pilot plant experiments, mathematical modelling and optimization. To estimate the kinetic parameters and to validate the kinetic models under different operating conditions, a set of experiments were carried out in a continuous flow isothermal trickle bed reactor using crude oil as a feedstock and commercial cobaltmolybdenum on alumina (Co-Mo/γ-Al2O3) as a catalyst. The reactor temperature was varied from 335°C to 400°C, the hydrogen pressure from 4 to10 MPa and the liquid hourly space velocity (LHSV) from 0.5 to 1.5 hr-1, keeping constant hydrogen to oil ratio (H2/Oil) at 250 L/L. The main hydrotreating reactions were hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeasphaltenization (HDAs) and hydrodemetallization (HDM) that includes hydrodevanadization (HDV) and hydrodenickelation (HDNi). An optimization technique is used to evaluate the best kinetic models of a trickle-bed reactor (TBR) process utilized for HDS, HDAs, HDN, HDV and HDNi of crude oil based on pilot plant experiments. The minimization of the sum of the squared errors (SSE) between the experimental and estimated concentrations of sulfur (S), nitrogen (N), asphaltene (Asph), vanadium (V) and nickel (Ni) compounds in the products, is used as an objective function in the optimization problem using two approaches (linear (LN) and non-linear (NLN) regression). The growing demand for high-quality middle distillates is increasing worldwide whereas the demand for low-value oil products, such as heavy oils and residues, is decreasing. Thus, maximizing the production of more liquid distillates of very high quality is of immediate interest to refiners. At the same time, environmental legislation has led to more strict specifications of petroleum derivatives. Crude oil hydrotreatment enhances the productivity of distillate fractions due to chemical reactions. The hydrotreated crude oil was distilled into the following fractions (using distillation pilot plant unit): light naphtha (L.N), heavy naphtha (H.N), heavy kerosene (H.K), light gas oil (L.G.O) and reduced crude residue (R.C.R) in order to compare the yield of these fractions produced by distillation after the HDT process with those produced by conventional methods (i.e. HDT of each fraction separately after the distillation). The yield of middle distillate showed greater yield compared to the middle distillate produced by conventional methods in addition to improve the properties of R.C.R. Kinetic models that enhance oil distillates productivity are also proposed based on the experimental data obtained in a pilot plant at different operation conditions using the discrete kinetic lumping approach. The kinetic models of crude oil hydrotreating are assumed to include five lumps: gases (G), naphtha (N), heavy kerosene (H.K), light gas oil (L.G.O) and reduced crude residue (R.C.R). For all experiments, the sum of the squared errors (SSE) between the experimental product compositions and predicted values of compositions is minimized using optimization technique. The kinetic models developed are then used to describe and analyse the behaviour of an industrial trickle bed reactor (TBR) used for crude oil hydrotreating with the optimal quench system based on experiments in order to evaluate the viability of large-scale processing of crude oil hydrotreating. The optimal distribution of the catalyst bed (in terms of optimal reactor length to diameter) with the best quench position and quench rate are investigated, based upon the total annual cost. The energy consumption is very important for reducing environmental impact and maximizing the profitability of operation. Since high temperatures are employed in hydrotreating (HDT) processes, hot effluents can be used to heat other cold process streams. It is noticed that the energy consumption and recovery issues may be ignored for pilot plant experiments while these energies could not be ignored for large scale operations. Here, the heat integration of the HDT process during hydrotreating of crude oil in trickle bed reactor is addressed in order to recover most of the external energy. Experimental information obtained from a pilot scale, kinetics and reactor modelling tools, and commercial process data, are employed for the heat integration process model. The optimization problem is formulated to optimize some of the design and operating parameters of integrated process, and minimizing the overall annual cost is used as an objective function. The economic analysis of the continuous whole industrial refining process that involves the developed hydrotreating (integrated hydrotreating process) unit with the other complementary units (until the units that used to produce middle distillate fractions) is also presented. In all cases considered in this study, the gPROMS (general PROcess Modelling System) package has been used for modelling, simulation and parameter estimation via optimization process.
20

Optimisation des colonnes HIDiC, intégrant une mousse métallique, basée sur une étude théorique et expérimentale des transferts thermiques / HIDiC optimization, containing metal foams, based on a theoretical and experimental study of heat transfer

Yala, Omar 14 November 2017 (has links)
La distillation est une opération unitaire de séparation qui est largement utilisée. Toutefois, lorsque les volatilités des corps à séparer sont proches, le besoin en énergie de la colonne augmente, et l’efficacité énergétique du procédé de séparation diminue. Ainsi, la faiblesse de la distillation est son efficacité énergétique (au maximum 10 %). La réduction de la consommation énergétique des colonnes à distiller est donc un enjeu majeur dans le contexte énergétique actuel. Une des voies prometteuses est les colonnes à distiller dites HIDiC (Heat Integrated Distillation Column). Dans ce type de configuration, la colonne est scindée en deux colonnes : une colonne d’appauvrissement et une colonne d’enrichissement. La colonne d’appauvrissement opère à un niveau de pression plus faible que la colonne d’enrichissement. Un compresseur ainsi qu’une vanne de détente sont installés pour ajuster les niveaux de pression respectifs dans les deux parties. La différence de pression ainsi établie permet d’imposer une différence de températures qui offre la possibilité de transférer de l’énergie entre les deux colonnes par l’intermédiaire d’une technologie de transfert de chaleur. Dans un premier temps, l’objet de cette étude est de valider une nouvelle technologie de transfert thermique pour les colonnes concentriques HIDiC. Cette technologie innovante, Mousse métallique à cellules ouvertes, est caractérisée et validée en comparant avec un garnissage classique. Pour cela, un pilote expérimental de colonne concentrique contenant le garnissage structuré a été mis en oeuvre au laboratoire. Les résultats des mousses métalliques ont montré une performance thermique plus importante que le garnissage classique avec un gain moyen de 102 %. La conductance thermique des mousses métallique à cellules ouvertes obtenue expérimentalement est de 1285 W.K-1. Ces résultats confirment l’intérêt de l’utilisation du garnissage innovant dans les colonnes de distillation HIDiC en tant que technologie de transfert de chaleur. Dans un deuxième temps, un outil de simulation des colonnes HIDiC est développé dans le logiciel commercial ProSim Plus™®. Par rapport aux colonnes de distillation conventionnelles, les colonnes HIDiC possèdent des paramètres spécifiques tels que le rapport de pression et le profil d’échange de chaleur entre les deux sections de la colonne. Une procédure d’optimisation est élaborée afin d’obtenir une colonne HIDiC avec un coût total annuel « TAC » minimal et une distribution énergétique optimale. La méthode stochastique est adoptée avec un algorithme génétique « AG » ou l’initialisation des variables d’action n’est pas nécessaire. Deux études de cas sont effectuées. L’une est un système largement étudié dans la littérature, le mélange (Benzène/Toluène). La procédure de conception et d’optimisation est évaluée. Une réduction du TAC de 7,4 % et 13,9 % est obtenue par rapport aux précédents travaux de la littérature. L’autre étude de cas est un mélange binaire (Cyclohexane/n-Heptane). Les résultats de la simulation concernant les quantités d’énergie échangées de la colonne d’enrichissement vers la colonne d’appauvrissement sont validés en vérifiant la faisabilité du transfert thermique par la conductance thermique de la technologie innovante obtenue expérimentalement UA (W.K-1). / Distillation is the most applied separation technology. Its major drawback is the low thermodynamic efficiency (typically around 10 %). In response to environmental issues that concern energy consumption of distillation column, HIDiC (heat integrated distillation column) which combines advantages of vapor recompression and diabatic operation is expected to have a large impact on energy saving. The mixtures with close boiling point are confirmed to be the best candidates for HIDiC. In fact, in this configuration the rectifying section and the stripping section are separated. Heat is transferred inside the distillation column from the rectifying to the stripping section, because the operating pressure (and thus the temperature) of the rectifying section is increased by means of the compressor. First, a novel technology of heat and mass transfer between rectifying column and stripping column is characterized and validated on an experimental pilot. A concentric HIDiC which contains metal foam packing is designed. Compared to the Raschig Super-Ring results, the heat transfer in this structured packing is more efficient, with a gain up to 102 %. The obtained thermal conductance UA (W.K-1) of the innovative column packing is 1285 W.K-1. This confirms the purpose of open cell metal foams use in HIDiC as a heat transfer technology. Secondly, the aim of this study is to optimize the HIDiC sensitive parameters so as to minimize the Total Annual Cost (TAC). For this, a HIDiC simulation model is developed by using commercial software ProSim Plus™®. GA (Genetic Algorithm) is used to find the optimal HIDiC configuration where variables are optimized without initialization. Binary (Benzene/Toluene) separation case is examined for the evaluation of the proposed method. As a result, 7.4 % and 13.9 % TAC reductions are realized in comparison with the reported solutions in previous works. Binary (Cyclohexane/n-Heptane) is studied to evaluate the physical feasibility of heat transfer between rectifying and stripping column by the experimental thermal conductance (UA experimental [W.K-1]) of the innovative column packing.

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