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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.
91

Multivariate Modeling in Chemical Toner Manufacturing Process

Khorami, Hassan January 2013 (has links)
Process control and monitoring is a common problem in high value added chemical manufacturing industries where batch processes are used to produce wide range of products on the same piece of equipment. This results in frequent adjustments on control and monitoring schemes. A chemical toner manufacturing process is representative of an industrial case which is used in this thesis. Process control and monitoring problem of batch processes have been researched, mostly through the simulation, and published in the past . However, the concept of applying the subject to chemical toner manufacturing process or to use a single indicator for multiple pieces of equipment have never been visited previously. In the case study of this research, there are many different factors that may affect the final quality of the products including reactor batch temperature, jacket temperature, impeller speed, rate of the addition of material to the reactor, or process variable associated with the pre-weight tank. One of the challenging tasks for engineers is monitoring of these process variables and to make necessary adjustments during the progression of a batch and change controls strategy of future batches upon completion of an existing batch. Another objective of the proposed research is the establishment of the operational boundaries to monitor the process through the usage of process trajectories of the history of the past successful batches. In this research, process measurements and product quality values of the past successful batches were collected and projected into matrix of data; and preprocessed through time alignment, centering, and scaling. Then the preprocessed data was projected into lower dimensions (latent variables) to produce latent variables and their trajectories during successful batches. Following the identification of latent variables, an empirical model was built through a 4-fold cross validation that can represent the operation of a successful batch. The behavior of two abnormal batches, batch 517 and 629, is then compared to the model by testing its statistical properties. Once the abnormal batches were flagged, their data set were folded back to original dimension to form a localization path for the time of abnormality and process variables that contributed to the abnormality. In each case the process measurement were used to establish operational boundaries on the latent variable space.
92

Development and demonstration of a new non-equilibrium rate-based process model for the hot potassium carbonate process.

Ooi, Su Ming Pamela January 2009 (has links)
Chemical absorption and desorption processes are two fundamental operations in the process industry. Due to the rate-controlled nature of these processes, classical equilibrium stage models are usually inadequate for describing the behaviour of chemical absorption and desorption processes. A more effective modelling method is the non-equilibrium rate-based approach, which considers the effects of the various driving forces across the vapour-liquid interface. In this thesis, a new non-equilibrium rate-based model for chemical absorption and desorption is developed and applied to the hot potassium carbonate process CO₂ Removal Trains at the Santos Moomba Processing Facility. The rate-based process models incorporate rigorous thermodynamic and mass transfer relations for the system and detailed hydrodynamic calculations for the column internals. The enhancement factor approach was used to represent the effects of the chemical reactions. The non-equilibrium rate-based CO₂ Removal Train process models were implemented in the Aspen Custom Modeler® simulation environment, which enabled rigorous thermodynamic and physical property calculations via the Aspen Properties® software. Literature data were used to determine the parameters for the Aspen Properties® property models and to develop empirical correlations when the default Aspen Properties® models were inadequate. Preliminary simulations indicated the need for adjustments to the absorber column models, and a sensitivity analysis identified the effective interfacial area as a suitable model parameter for adjustment. Following the application of adjustment factors to the absorber column models, the CO₂ Removal Train process models were successfully validated against steady-state plant data. The success of the Aspen Custom Modeler® process models demonstrated the suitability of the non-equilibrium rate-based approach for modelling the hot potassium carbonate process. Unfortunately, the hot potassium carbonate process could not be modelled as such in HYSYS®, Santos’s preferred simulation environment, due to the absence of electrolyte components and property models and the limitations of the HYSYS® column operations in accommodating chemical reactions and non-equilibrium column behaviour. While importation of the Aspen Custom Modeler® process models into HYSYS® was possible, it was considered impractical due to the significant associated computation time. To overcome this problem, a novel approach involving the HYSYS® column stage efficiencies and hypothetical HYSYS® components was developed. Stage efficiency correlations, relating various operating parameters to the column performance, were derived from parametric studies performed in Aspen Custom Modeler®. Preliminary simulations indicated that the efficiency correlations were only necessary for the absorber columns; the regenerator columns were adequately represented by the default equilibrium stage models. Hypothetical components were created for the hot potassium carbonate system and the standard Peng-Robinson property package model in HYSYS® was modified to include tabular physical property models to accommodate the hot potassium carbonate system. Relevant model parameters were determined from literature data. As for the Aspen Custom Modeler® process models, the HYSYS® CO₂ Removal Train process models were successfully validated against steady-state plant data. To demonstrate a potential application of the HYSYS® process models, dynamic simulations of the two most dissimilarly configured trains, CO₂ Removal Trains #1 and #7, were performed. Simple first-order plus dead time (FOPDT) process transfer function models, relating the key process variables, were derived to develop a diagonal control structure for each CO₂ Removal Train. The FOPDT model is the standard process engineering approximation to higher order systems, and it effectively described most of the process response curves for the two CO₂ Removal Trains. Although a few response curves were distinctly underdamped, the quality of the validating data for the CO₂ Removal Trains did not justify the use of more complex models than the FOPDT model. While diagonal control structures are a well established form of control for multivariable systems, their application to the hot potassium carbonate process has not been documented in literature. Using a number of controllability analysis methods, the two CO₂ Removal Trains were found to share the same optimal diagonal control structure, which suggested that the identified control scheme was independent of the CO₂ Removal Train configurations. The optimal diagonal control structure was tested in dynamic simulations using the MATLAB® numerical computing environment and was found to provide effective control. This finding confirmed the results of the controllability analyses and demonstrated how the HYSYS® process model could be used to facilitate the development of a control strategy for the Moomba CO₂ Removal Trains. In conclusion, this work addressed the development of a new non-equilibrium rate-based model for the hot potassium carbonate process and its application to the Moomba CO₂ Removal Trains. Further work is recommended to extend the model validity over a wider range of operating conditions and to expand the dynamic HYSYS® simulations to incorporate the diagonal control structures and/or more complex control schemes. / http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1350259 / Thesis (Ph.D.) - University of Adelaide, School of Chemical Engineering, 2009
93

Development and demonstration of a new non-equilibrium rate-based process model for the hot potassium carbonate process.

Ooi, Su Ming Pamela January 2009 (has links)
Chemical absorption and desorption processes are two fundamental operations in the process industry. Due to the rate-controlled nature of these processes, classical equilibrium stage models are usually inadequate for describing the behaviour of chemical absorption and desorption processes. A more effective modelling method is the non-equilibrium rate-based approach, which considers the effects of the various driving forces across the vapour-liquid interface. In this thesis, a new non-equilibrium rate-based model for chemical absorption and desorption is developed and applied to the hot potassium carbonate process CO₂ Removal Trains at the Santos Moomba Processing Facility. The rate-based process models incorporate rigorous thermodynamic and mass transfer relations for the system and detailed hydrodynamic calculations for the column internals. The enhancement factor approach was used to represent the effects of the chemical reactions. The non-equilibrium rate-based CO₂ Removal Train process models were implemented in the Aspen Custom Modeler® simulation environment, which enabled rigorous thermodynamic and physical property calculations via the Aspen Properties® software. Literature data were used to determine the parameters for the Aspen Properties® property models and to develop empirical correlations when the default Aspen Properties® models were inadequate. Preliminary simulations indicated the need for adjustments to the absorber column models, and a sensitivity analysis identified the effective interfacial area as a suitable model parameter for adjustment. Following the application of adjustment factors to the absorber column models, the CO₂ Removal Train process models were successfully validated against steady-state plant data. The success of the Aspen Custom Modeler® process models demonstrated the suitability of the non-equilibrium rate-based approach for modelling the hot potassium carbonate process. Unfortunately, the hot potassium carbonate process could not be modelled as such in HYSYS®, Santos’s preferred simulation environment, due to the absence of electrolyte components and property models and the limitations of the HYSYS® column operations in accommodating chemical reactions and non-equilibrium column behaviour. While importation of the Aspen Custom Modeler® process models into HYSYS® was possible, it was considered impractical due to the significant associated computation time. To overcome this problem, a novel approach involving the HYSYS® column stage efficiencies and hypothetical HYSYS® components was developed. Stage efficiency correlations, relating various operating parameters to the column performance, were derived from parametric studies performed in Aspen Custom Modeler®. Preliminary simulations indicated that the efficiency correlations were only necessary for the absorber columns; the regenerator columns were adequately represented by the default equilibrium stage models. Hypothetical components were created for the hot potassium carbonate system and the standard Peng-Robinson property package model in HYSYS® was modified to include tabular physical property models to accommodate the hot potassium carbonate system. Relevant model parameters were determined from literature data. As for the Aspen Custom Modeler® process models, the HYSYS® CO₂ Removal Train process models were successfully validated against steady-state plant data. To demonstrate a potential application of the HYSYS® process models, dynamic simulations of the two most dissimilarly configured trains, CO₂ Removal Trains #1 and #7, were performed. Simple first-order plus dead time (FOPDT) process transfer function models, relating the key process variables, were derived to develop a diagonal control structure for each CO₂ Removal Train. The FOPDT model is the standard process engineering approximation to higher order systems, and it effectively described most of the process response curves for the two CO₂ Removal Trains. Although a few response curves were distinctly underdamped, the quality of the validating data for the CO₂ Removal Trains did not justify the use of more complex models than the FOPDT model. While diagonal control structures are a well established form of control for multivariable systems, their application to the hot potassium carbonate process has not been documented in literature. Using a number of controllability analysis methods, the two CO₂ Removal Trains were found to share the same optimal diagonal control structure, which suggested that the identified control scheme was independent of the CO₂ Removal Train configurations. The optimal diagonal control structure was tested in dynamic simulations using the MATLAB® numerical computing environment and was found to provide effective control. This finding confirmed the results of the controllability analyses and demonstrated how the HYSYS® process model could be used to facilitate the development of a control strategy for the Moomba CO₂ Removal Trains. In conclusion, this work addressed the development of a new non-equilibrium rate-based model for the hot potassium carbonate process and its application to the Moomba CO₂ Removal Trains. Further work is recommended to extend the model validity over a wider range of operating conditions and to expand the dynamic HYSYS® simulations to incorporate the diagonal control structures and/or more complex control schemes. / http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1350259 / Thesis (Ph.D.) - University of Adelaide, School of Chemical Engineering, 2009
94

The computer-aided synthesis of chemical process designs

Siirola, Jeffrey J., January 1970 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
95

Automatic clustering with application to time dependent fault detection in chemical processes

Labuschagne, P. J. January 2009 (has links)
Thesis (M.Eng.(Control Engineering))--University of Pretoria, 2008. / Summary in English. Includes bibliographical references.
96

Synthesis of transition metal oxides and hydroxides by soft-chemistry routes.

January 2009 (has links)
Chan, Mui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstract also in Chinese. / Abstract --- p.i / Abstract (Chinese) --- p.iii / Declaration --- p.v / Acknowledgement --- p.vi / Table of Contents --- p.viii / List of Tables --- p.xiv / List of Figures --- p.xv / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Soft-Chemistry --- p.7 / Chapter 1.2.1 --- Sol-Gel Method --- p.7 / Chapter 1.2.2 --- Co-precipitation --- p.9 / Chapter 1.2.3 --- Microemulsion --- p.10 / Chapter 1.3 --- Application of Hydrothermal/Solvothermal Methods in Materials Synthesis --- p.12 / Chapter 1.3.1 --- Fundamentals of Hydrothermal and Solvothermal Methods --- p.12 / Chapter 1.3.2 --- Advantages of Hydrothermal/Solvothermal Methods in contrast to Conventional Synthetic Approaches --- p.13 / Chapter 1.3.3 --- Hydrothermal and Solvothermal Preparation of Materials --- p.14 / Chapter 1.4 --- Application of Transition Metal Oxides As Functional Materials --- p.15 / Chapter 1.5 --- Aim and Scope of Work --- p.16 / Chapter 1.6 --- References --- p.17 / Chapter Chapter 2: --- Solvothermal and Hydrothermal Template Free Synthesis of ZnO Microspheres / Chapter 2.1 --- Introduction --- p.23 / Chapter 2.2 --- Experimental Section --- p.25 / Chapter 2.2.1 --- Synthesis of ZnO Microspheres by Solvothermal Method --- p.25 / Chapter 2.2.2 --- Synthesis of ZnO Microspheres by Hydrothermal Method --- p.26 / Chapter 2.2.3 --- Doping ZnO Microspheres with Silver or Gallium by Solvothermal Method --- p.26 / Chapter 2.2.4 --- Characterization --- p.27 / Chapter 2.2.5 --- Measurement of Photocatalytic Activity --- p.29 / Chapter 2.3 --- Results and Discussion --- p.30 / Chapter 2.3.1 --- X-Ray Diffraction Analysis --- p.30 / Chapter 2.3.1.1 --- ZnO-HT and ZnO-ST --- p.30 / Chapter 2.3.1.2 --- ZnO-ST: Effect of Different Concentrations of Zinc Acetate --- p.33 / Chapter 2.3.1.3 --- Doping ZnO-ST with Silver or Gallium --- p.34 / Chapter 2.3.2 --- SEM study --- p.36 / Chapter 2.3.2.1 --- ZnO-HT and ZnO-ST --- p.36 / Chapter 2.3.2.2 --- ZnO-HT-Different Volume Ratios of Ethylene Glycol to Water --- p.37 / Chapter 2.3.2.3 --- ZnO-ST --- p.39 / Chapter 2.3.2.3.1 --- Different Volume Ratios of Benzyl Alcohol to Ethylene Glycol --- p.40 / Chapter 2.3.2.3.2 --- Different Concentrations of Zinc Acetate --- p.41 / Chapter 2.3.2.3.3 --- Different Concentrations of Urea --- p.42 / Chapter 2.3.3 --- TEM Study --- p.44 / Chapter 2.3.3.1 --- TEM and HRTEM of ZnO-HT --- p.44 / Chapter 2.3.3.2 --- TEM and HRTEM of ZnO-ST --- p.45 / Chapter 2.3.3.3 --- TEM Images of Ga-Doped ZnO-ST --- p.47 / Chapter 2.3.3.4 --- TEM Images of Ag-Doped ZnO-ST --- p.49 / Chapter 2.3.4 --- Nitrogen Adsorption and Desorption --- p.50 / Chapter 2.3.5 --- X-Ray Photoelectron Spectroscopy --- p.52 / Chapter 2.3.5.1 --- XPS Study of ZnO-ST --- p.52 / Chapter 2.3.5.2 --- XPS Study of ZnO-HT --- p.54 / Chapter 2.3.5.3 --- XPS Study of Silver Doped ZnO-ST --- p.56 / Chapter 2.3.5.4 --- XPS Study of Gallium Doped ZnO-ST --- p.58 / Chapter 2.3.6 --- FR-IR Spectra --- p.60 / Chapter 2.3.7 --- Photocatalytic Activity on Degradation of Methylene Blue --- p.61 / Chapter 2.3.8 --- Proposed Formation Mechanism for ZnO-ST --- p.64 / Chapter 2.3.9 --- Proposed Formation Mechanism for ZnO-HT --- p.68 / Chapter 2.3.10 --- Optical Property of ZnO Microspheres --- p.69 / Chapter 2.4 --- Conclusion --- p.73 / Chapter 2.5 --- References --- p.74 / Chapter Chapter 3: --- Synthesis of Hierarchical Porous Lithium Niobate Submicrometer Rods / Chapter 3.1 --- Introduction --- p.79 / Chapter 3.2 --- Experimental Section --- p.81 / Chapter 3.2.1 --- Characterization --- p.82 / Chapter 3.3 --- Results and Discussion --- p.83 / Chapter 3.3.1 --- X-Ray Diffraction Analysis --- p.83 / Chapter 3.3.2 --- SEM Study --- p.86 / Chapter 3.3.2.1 --- Surfactants Dependent Morphologies Change --- p.86 / Chapter 3.3.2.2 --- Concentrations of CTAB --- p.87 / Chapter 3.3.2.3 --- Time Dependent Morphologies Change --- p.88 / Chapter 3.3.3 --- TEM Study --- p.91 / Chapter 3.3.5 --- XPS Analysis --- p.93 / Chapter 3.3.6 --- BET Analysis --- p.96 / Chapter 3.3.7 --- Proposed Formation Mechanism --- p.97 / Chapter 3.3.7.1 --- Effect of Microemulsion --- p.97 / Chapter 3.3.7.2 --- Effect of CTAB --- p.98 / Chapter 3.3.7.3 --- Ostwald Ripening --- p.99 / Chapter 3.3.7.4 --- Formation of LiNi3O8 --- p.101 / Chapter 3.4 --- Conclusion --- p.102 / Chapter 3.5 --- References --- p.103 / Chapter Chapter 4: --- Flower-Like α-Nickel Hydroxide synthesized by hydrothermal method / Chapter 4.1 --- Introduction --- p.106 / Chapter 4.2 --- Experimental Section --- p.108 / Chapter 4.2.1 --- Synthesis of Nickel Hydroxide by Hydrothermal Method --- p.108 / Chapter 4.2.2 --- Characterization --- p.109 / Chapter 4.3 --- Results and Discussion --- p.111 / Chapter 4.3.1 --- X-Ray Diffraction Analysis --- p.111 / Chapter 4.3.2 --- SEM Study --- p.115 / Chapter 4.3.3 --- TEM and HRTEM Study --- p.116 / Chapter 4.3.4 --- XPS Analysis --- p.117 / Chapter 4.3.5 --- FT-IR Analysis --- p.119 / Chapter 4.3.6 --- BET analysis --- p.120 / Chapter 4.3.7 --- Proposed Formation Mechanism of the Flower like α-Ni(OH)2 --- p.122 / Chapter 4.4 --- Conclusion --- p.123 / Chapter 4.5 --- References --- p.124 / Chapter Chapter 5: --- Conclusions and Future Work / Chapter 5.1 --- Conclusions --- p.127 / Chapter 5.2 --- Future work --- p.129
97

Efeito da adição de boro na microestrutura, dureza, resistência à oxidação e ao desgaste do aço inoxidável austenítico 316L sinterizado.

Peruzzo, Marcele 26 February 2016 (has links)
Este trabalho analisa o efeito da adição de boro ao aço inoxidável austenítico 316L como um aditivo da sinterização no processo de metalurgia do pó. O efeito do B foi investigado em termos da densificação, microestrutura, dureza, resistência à oxidação e ao desgaste. Os pós de 316L foram misturados com 0,6% e 0,8% em massa de boro, compactados unixialmente a 800 MPa e sinterizados em atmosfera de argônio, a uma taxa de 10°C.min-1 na temperatura de 1240°C durante 30 min. A microestrutura e as fases cristalinas das amostras sinterizadas foram avaliadas por microscopia ótica, microscopia eletrônica de varredura por emissão de campo (MEV-FEG), espectroscopia de raios X por dispersão de energia (EDS) e difração de raios X (DRX) utilizando o método de refinamento Rietveld. A técnica de calorimetria diferencial exploratória (DSC) foi realizada para estudar o comportamento das amostras de 316L com e sem adição de boro, nos estados sólido e líquido. A macrodureza das amostras sinterizadas foi medida na escala Vickers e a microdureza das fases formadas foi medida por meio de ensaios de indentação instrumentada. A composição química dos óxidos formados nas amostras de 316L com e sem adição de boro após os ensaios de oxidação cíclica nas temperaturas de 800°C, 900°C e 1000°C foram determinados por EDS e DRX. O coeficiente de atrito e o coeficiente de desgaste específico das amostras sinterizadas foram determinados por meio do ensaio de deslizamento alternado e os mecanismos de desgastes foram investigados por meio das técnicas de MEV-FEG e EDS. A adição de boro no 316L resulta em uma reação eutética entre o boro e a matriz austenítica do 316L. Os resultados de EDS e DRX revelaram a formação de dois boretos do tipo M2B ricos em Fe, Cr e Mo, (Fe,Cr)2B e (Cr,Mo)2B, provenientes da reação eutética, os quais se concentraram principalmente no contorno dos grãos austeníticos. A formação dos boretos do tipo M2B favoreceu a densificação, através da fase líquida formada durante a sinterização e promoveu o aumento da dureza, da resistência à oxidação e ao desgaste do aço inoxidável austenítico 316L. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES / This work analyses boron additions to AISI 316L austenitic stainless steels, as a sintering additive in the powder metallurgy process. The effect of boron addition was investigated in terms of densification, microstructure, hardness, oxidation resistance and wear behavior. Samples were prepared with 0.6 wt.% and 0.8 wt.% of boron, pressed to 800 MPa and sintered under argon atmosphere. Sintering cycle involved heating up to the sintering temperature of 1240°C, at a rate of 10°C.min-1, holding at this peak temperature for 30 min. Microstructure of the sintered bodies was examined by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD), using Rietveld refinement. Differential scanning calorimetry (DSC) was used to study the behavior of both the free and boron-containing 316L samples at solid and liquid states. The Vickers hardness of sintered samples was assessed. Microhardness was evaluated using instrumented indentation. The oxide chemical composition of 316L without and containing boron samples, after cyclic oxidation at 800°C, 900°C and 100°C, was determined by EDS and XRD. The friction coefficients and specific wear coefficient of sintered samples were determined by reciprocating sliding and the wear mechanisms by FESEM and EDS. Boron addition to AISI 316L steel resulted in an eutectic reaction between the austenitic matrix and boron. EDS and XRD results revealed the formation of (Fe,Cr)2B and (Cr,Mo)2B borides, from eutectic reaction, which were concentrated mainly in intergranular sites. The formation of M2B borides favored material densification through the development of a liquid phase during sintering, and promoted an increase in hardness, oxidation and wear resistance of AISI 316L steel.
98

Variação da energia do gap em filmes finos de CdS / Band gap variation of CdS thin films

Carneiro, Luiz Carlos Cunha 28 February 1996 (has links)
Orientador: Roberto de Toledo Assumpção, Jorge Ivan Cisneros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-21T06:08:40Z (GMT). No. of bitstreams: 1 Carneiro_LuizCarlosCunha_M.pdf: 13306398 bytes, checksum: a8cc72f601e22e70353938019781d5df (MD5) Previous issue date: 1996 / Resumo: Filmes finos de CdS foram preparados sobre lâminas de vidro para microscopia e caracterizados morfológica, estrutural e opticamente. Os resultados de microscopia eletrônica (transmissão e varredura) mostraram que o filme é composto de duas camadas distintas: um depósito amorfo e uma segunda camada policristalina constituída por uma mistura de fases wurtzita e zinc blend (difração de elétrons e raios-X). Como resultado da existência destas camadas, da presença das fases alotrópicas e também de fIutuações estequiométricas, os filmes apresentaram variações nas propriedades ópticas, sendo de particular importância a variação da Eg da ordem de 100 meV em torno do gap óptico aceito para o CdS (Eg = 2,42 eV) / Abstract: Cadmium sulphide have much technological attraction for their application on heterojunction optoelectronic devices, particularly solar cells. In this work we study thin films ofthis material, prepared by chemical bath deposition (CBD) process. Morphologic, structural and stoichiometric data are correlated to the optical properties, namely the energy gap (Eg). Scanning Electron Microscopy and Transmission Electron Diffraction showed that the whole film is composed as thin amorphous layer preceding a thick polycrystalline phase. Transmitance and refletance measurements carried out on specimens in the 0,4 - 2,4 um thickness range showed a variation in Eg (about 200 meV) which can be understood in terms of the other above mentioned properties (surface morphology, stoichiometry and this relative proportion of the amorphous to the crystalline phase) / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
99

Desenvolvimento de uma instalação de separação de gases por adsorção e modelagem do processo

Neves, Celia de Figueiredo Cordeiro 24 May 2000 (has links)
Orientadores: Elizabete Jordão, Wander Luiz Vasconcelos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-07-26T17:41:33Z (GMT). No. of bitstreams: 1 Neves_CeliadeFigueiredoCordeiro_D.pdf: 6279733 bytes, checksum: 0ef1f876a9ab54c6121a14df07295fd6 (MD5) Previous issue date: 2000 / Resumo: Os processos de separação são normalmente responsáveis pelos maiores custos de produção nas indústrias químicas, petroquímicas e correlatas. A aplicação comercial de processos adsortivos de separação de gases conhecidos como PSA ("Pressure Swing Adsorption"), têm tido uma aceitação crescente na indústria, pois eles são mais eficientes e econômicos do que os processos de separação convencionais, para pequenas e médias capacidades de produção. O objetivo deste trabalho é desenvolver uma instalação de separação de gases por PSA para a produção de ar enriquecido na faixa de 25 a 50 % de oxigênio, para aplicação em processos de combustão e oxidação, e construir um modelo que permita descrever o comportamento do processo, levando em consideração três parâmetros de avaliação: a pureza e recuperação do produto e a produtividade do adsorvente. Para alcançar os objetivos propostos foi projetada e construída uma instalação laboratorial de PSA utilizando um adsorvente à base de zeólita 5A. O sistema de automação e controle da instalação consiste de um controlador lógico programável conectado a um microcomputador via sistema supervisório, e a diversas válvulas solenóides e instrumentos de medição de vazão, pressão, concentração e temperatura. O projeto e a construção da instalação exigiram um grande esforço de pesquisa e estudo, e conduziram à fonnação de uma equipe multidisciplinar com especialistas em áreas como processos, materiais, automação e controle, que muito contribuiu para a consolidação da pesquisa. Através da utilização de um planejamento fatorial de experimentos foi possível obter modelos empíricos satisfatórios para a pureza, recuperação e produtividade em função das condições operacionais, com erros médios variando entre 1 % e 4 %. Os resultados dos experimentos e as simulações realizadas mostraram que a instalação desenvolvida é capaz de produzir ar enriquecido a 43 % O2, com uma recuperação de 50 % e produtividade de 0,06 moI O_g.ciclo. A otimização do processo foi facilitada pela utilização de outro parâmetro de avaliação do processo, denominado capacidade separativa, que utiliza conceitos básicos da teoria de cascatas aplicada a separações isotópicas / Abstract: Separation processes account for the major production costs in chemical, petrochemical and related industries. Commercial pressure swing adsorption processes (the so-called PSA processes) have been intensively applied in industry since they need lower energy and are less costly than conventional separation processes for low to medium production rates. This work aims to develop a gas separation unit by the PSA process to produce oxygen enriched air between 25 % and 50 % to be used in combustion and oxidation processes. Another objective is to build a model of the process by which its performance can be evaluated through three parameters: product purity, product recovery and adsorbent productivity. To reach these objectives a PSA unit of laboratory scale was designed and built, that uses a bed filled with a type 5A-zeolite adsorbent. Instruments for measuring flow rate, pressure, concentration and temperatures and solenoid valves were linked to a programmable logic controller. A computer was used for data acquisition and to control the experimental set-up. Great effort of research and study placed for design and construction of the installation required a multidisciplinary team of specialists in many fields like processes, materials, automation and control, which was very helpful to consolidate the present research. Using a factorial design of experiments it was possible to develop appropriate empirical models for evaluating purity, recovery and productivity against operational conditions, with mean errors varying between I and 4%. The experimental results and executed simulations of the process showed that the PSA unit works properly for production of oxygen enriched air at a purity of 43 %, recovery around 50 % and productivity of 0,06 mol Ozlkg.cic1o. The process was optimized by another parameter, called separative capacity, which uses basic concepts of cascade theory applied to isotope separations / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química
100

Simulação de destilador molecular de filme descendente para destilar frações pesadas de petroleo / Simulation of falling film molecular distillator for istillations of petroleum heavy fraction

Mallmann, Evandro Stoffels, 1983- 15 August 2018 (has links)
Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T12:56:55Z (GMT). No. of bitstreams: 1 Mallmann_EvandroStoffels_M.pdf: 5927500 bytes, checksum: 1142d105683d77d9dfbe069513e8abce (MD5) Previous issue date: 2010 / Resumo: O Petróleo obtido nas bacias brasileiras é do tipo pesado e ultra pesado, apresentando alta viscosidade, que dificulta sua exploração (retirada do petróleo dos campos submarinos) e também as operações de refino para obtenção de combustíveis outros derivados. Os processos de refino atualmente em atividade nas refinarias não permitem a operação de óleos pesados e ultra pesados, de forma que estes são misturados a óleos leves para seu processamento. Este procedimento leva à dependência do Brasil em importação de petróleo, assim como a não completa valoração do óleo encontrado no país. Dentro deste contexto, a utilização da Destilação Molecular se apresenta como alternativa à operação inicial de óleos pesados e ultra pesados. Experimentos realizados nos Laboratórios de Desenvolvimento de Processos Separação (LDPS) e de Otimização, Projeto e Controle Avançado (LOPCA) mostraram a viabilidade de seu emprego. Porém, é necessária uma ampla investigação para desenvolvimento de políticas operacionais que levem a operação de destiladores moleculares com alto desempenho para refino de petróleo. Para tanto, é necessário o desenvolvimento de simulações que permitam um extensivo estudo cobrindo as possíveis faixas operacionais, que são funções das características do petróleo. Propõe-se assim, neste trabalho, o desenvolvimento de simulações para a destilação molecular tipo filme descendente fazendo-se uso do simulador comercial Aspen Plus®, que possui facilidades de pacotes termodinâmicos para a realização da tarefa. Dados experimentais já disponíveis foram usados para a análise e avaliação das simulações. / Abstract: The petroleum gotten in the Brazilian basins is of the types heavy and ultra-heavy, presenting high viscosities that make difficult its exploration (remove of the oil from submarine fields) and also the operations of refining for fuel attainment and other derivatives. The processes of refining, currently in activity, in the refineries, do not allow the heavy and ultra-heavy oil operation, so that these are mixed with light oils for its processing. This procedure leads to the dependence of Brazil in importation of oil, as well as not complete valuation of the oil found in the country. Inside this context, the use of molecular distillation is presented as an alternative to initial operation of heavy and ultra-heavy oil. Experiments carried through in the Laboratories of Development of Processes of Separation (LDPS) and Optimization, Project and Advanced Control (LOPCA) had shown the viability of this operation. However, is necessary an ample inquiry for development of operational politics that take the operation of molecular distillers with high performance for oil refining. For this purpose, the development of simulations that allow an extensive study covering the possible operational bands, that are functions of the characteristics of the oil, is necessary. It is considered thus, in this work, the development of a descendant filmed distiller simulations using the commercial simulator Aspen Plus®, that possess easiness of thermodynamic packages for the accomplishment of the task. Available experimental data were used for the analysis and evaluation of the simulations. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

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