La tradicional reacción de hidrogenación es un proceso catalítico heterogéneo, cuya baja velocidad de reacción es debida a la resistencia a la transferencia de masa y la baja solubilidad del hidrógeno (H2) en el substrato. Mediante el agregado de un solvente en estado supercrítico, capaz de solubilizar tanto al substrato como al gas, es posible llevar a cabo la hidrogenación en fase homogénea. De esta manera, se eliminan las restricciones de solubilidad y de transferencia de masa, logrando una mejor selectividad del proceso y mayo-res velocidades de reacción. Es necesario conocer del compor-tamiento del equilibrio entre fases de la mezcla, para determi-nar el beneficio del uso del estado supercrítico e interpretar su efecto. La región supercrítica de mezclas multicomponen-tes, presenta un comportamiento complejo altamente sensible a la composición y a las condiciones de presión y temperatura del proceso. Es el objetivo principal de esta tesis aportar infor-mación experimental que ayude al entendimiento del equilibrio entre fases que puede ocurrir en procesos de hidrogenación supercrítica. En el Capítulo I se presentan los conceptos bási-cos sobre fluidos supercríticos, sus características, propieda-des físicas y comportamientos particulares. Se desarrolla una revisión del equilibrio entre fases para sistemas binarios y ternarios; herramientas necesarias para el desarrollo de esta tesis. El Capítulo II, consiste en una breve descripción, consi-derando pasado, presente y futuro, de las aplicaciones de los fluidos supercríticos; son desarrollados los aspectos de mayor importancia de las reacciones llevadas a cabo en medio super-crítico, haciendo hincapié en la hidrogenación catalítica hete-rogénea de compuestos de elevado peso molecular. Equilibrio entre Fases en Procesos de Hidrogenación en Medios Super-críticos. En el Capítulo III, los posibles métodos experimen-tales utilizados para la medición del equilibrio de fases a alta presión, para sistemas que contengan un fluido supercrítico o cuasi-crítico son descriptos de manera general. Se detallan, el equipamiento utilizado, la metodología y los procedimientos experimentales empleados en el desarrollo de esta tesis, para obtener los datos de equilibrio requeridos para el análisis del comportamiento de fases, utilizando propano como solvente supercrítico. Para el análisis del comportamiento de fases de sistemas sometidos a hidrogenación supercrítica, dos diferen-tes procesos de importancia en la industria fueron abordados: la hidrogenación de aceites vegetales y la hidrogenólisis de metil ésteres de ácidos grasos. La hidrogenación de aceites vegetales abarca el Capítulo IV de esta tesis. Se explica de-talladamente cuál es la problemática que presentan los procesos de hidrogenación tradicionales de compuestos de elevado peso molecular, se proporcionan y analizan los datos experimentales obtenidos del equilibrio entre fases de los componentes involucrados en la reacción; información que ayuda a identificar el comportamiento de este sistema y esta-blecer lineamientos generales aplicables a diferentes proce-sos. La hidrogenólisis de metil ésteres de ácidos grasos pre-senta la misma problemática y es estudiada en el Capítulo V. En este capítulo de tesis se determina y estudia el equilibrio entre fases para sistemas representativos de los componen-tes involucrados en dicho proceso. Equilibrios multifásicos y el fenómeno de condensación retrógrada para sistemas terna-rios, fueron determinados. Esta información permite evaluar de la utilización de solventes supercríticos como alternativa tecnológica. / The traditional reaction of hydrogenation is a heterogeneous catalytic process, in which the mass transfer resistance and the low solubility of hydrogen (H2) in the substrate, determine very low reaction rates. With the addition of a supercritical solvent, miscible with both, the substrate and the gas, it is possible to carry out the reaction in a homogenous phase. In this way, solubility and mass transfer restrictions are elimina-ted and the selectivity and reaction rate of the process can be drastically improved. The knowledge of the phase behavior of the mixture is necessary to take advantages of the benefit in using supercritical fluids and also to get e better unders-tanding of the process. The supercritical region of multicompo-nent mixtures shows a complex behavior, highly sensitive to the composition of the mixture and to the pressure and temperature of the process. It is the aim of this project to provide experimental information that covers the various sceneries expected in supercritical hydrogenation processes. In Chapter I the basic concepts related with supercritical fluids, its characteristics, physical properties and particular behavior are summarized. A review of the phase behavior of binary and ternary mixtures is done; those are necessary tools for the development of this thesis. Chapter II, contain a brief description, about past, present and future of the appli-cations of the supercritical fluids; the relevance of carrying out reactions in supercritical media is discussed, emphasizing the heterogeneous catalysis hydrogenation of heavy compo-nents. In Chapter III, the experimental methods for the measurement of phase equilibria at high pressure, for systems that contain supercritical or near-critical fluids are generally described. Phase Equilibrium forHydrogenation Processes in Supercritical Media. The equipment used in this thesis to obtain experimental equilibrium data for the analysis of phase behavior of supercritical hydrogenation systems using propane as a supercritical solvent is detailed, as well as the methodolo-gy and experimental procedures. For the analysis of the phase behavior of supercritical hydrogenation systems, two commer-cial processes were considered: hydrogenation of vegetable oils and hydrogenolysis of fatty acids methyl esters. Hydroge-nation of vegetable oils is analyzed in Chapter IV of this the-sis. The problems of the traditional hydrogenation process for heavy components, is explained in detail, the experimental data measured are presented and analyzed; this information helps to identify the behavior of this system and to made general considerations applicable to different processes. The hydrogenolysis of fatty acids methyl esters has similar featu-res and the study of this system is presented in Chapter V, in which the phase behavior of the representative components of the system is determined and discussed. Regions of multi-phase behavior and retrograde phenomena are observed for ternary mixtures and not expected from the binary data. This information contributes to the evaluation of supercritical hydrogenation as a technological alternative.

La búsqueda constante de nuevos procesos alternativos aplicables a la industria química y nutracéutica ha llevado a la tecnología supercrítica a ocupar un lugar de privilegio. Las propiedades inherentes de los fluidos supercríticos les confie-ren la característica de solventes limpios. Consumidores cada vez más exigentes en los niveles residuales de solventes -resultantes del procesado tradicional de alimentos y productos farmacéuticossumado a las estrictas regulaciones medioam-bientales, son las razones fundamentales que impulsan el inte-rés por esta nueva tecnología. En esta Tesis se analiza la factibilidad operativa y económica para llevar a cabo procesos supercríticos aplicados a la extracción de productos naturales. La Tesis fue dividida en dos partes, la primera agrupando aquellos capítulos referidos al Modelado Termodinámico de pro-ductos naturales y derivados y sus mezclas con fluidos super-críticos (Capítulos 1 a 4) y la segunda parte conteniendo los capítulos de análisis, simulación, y diseño óptimo de procesos de extracción, refinado y fraccionamiento a alta presión. En el Capítulo 1 se discute acerca de las propiedades y aplicaciones generales de los fluidos supercríticos con especial atención en aquellas relacionadas al procesamiento de productos naturales. En el Capítulo 2, el equilibrio de fases a alta presión es anali-zado sobre la base de diagramas de fase de mezclas binarias y ternarias, y su extensión a mezclas multicomponentes. Se realiza un estudio detallado de las regiones que presentan equilibrio monofásico, di y trifásico, para mezclas de alcanos, aromáticos, triglicéridos y aceites con etano, propano y CO2, en el rango completo de presiones, temperaturas y composi-ciones. En el Capítulo 3, la importancia del modelado del equi-librio supercrítico entre fases es analizada a partir de una revi-sión de las ecuaciones de estado más recientes, con vistas a determinar el modelo termodinámico más adecuado para el modelado del equilibrio a alta presión de sistemas multicompo-nentes, altamente no ideales. En el Capítulo 4, la ecuación de estado a contribución grupal, GC-EOS, es extendida para cu-brir los sistemas de interés para esta Tesis. Se evalúan distin-tas metodologías de caracterización de las complejas mezclas que conforman los aceites y se obtienen los parámetros gru-pales necesarios para reproducir el comportamiento de equili-brio de una extensa lista de sistemas binarios. Correlaciones y predicciones del modelo GC-EOS son validadas contra datos experimentales y comparadas a aquellas obtenidas con otras ecuaciones de estado. Los Capítulos 5, 6 y 7 abarcan el pro-cesamiento de distintos productos naturales utilizando fluidos supercríticos como solventes. En todos ellos, el objetivo es determinar condiciones operativas óptimas que permitan llevar a cabo un proceso particular al menor costo, cumpliendo con las exigencias de pureza y recuperación de productos impues-tas por el mercado y aplicando una tecnología alternativa limpia. Cada uno de tales capítulos contiene básicamente tres secciones: modelado termodinámico de los sistemas involucra-dos -utilizando los resultados obtenidos en el Capítulo 4-,simu-lación del proceso en condiciones reportadas en la literatura de experimentos a escala piloto y optimización de condiciones con diferentes funciones objetivo. En el Capítulo 5, se estudia un proceso de purificación de aceites vegetales utilizando pro-pano y dióxido de carbono supercríticos como posibles sol-ventes. En el Capítulo 6 se analiza el fraccionamiento supercrí-tico de etil ésteres de aceites de pescado y los esquemas óptimos de recuperación de ésteres de ácidos grasos poliin-saturados w-3, de alto valor agregado. En el Capítulo 7, el refinado de aceites esenciales cítricos es resuelto empleando dióxido de carbono supercrítico, sobre la base de modelos termodinámicos confiables y rigurosas subrutinas de optimiza-ción. El diseño óptimo de un proceso de desterpenación de aceite de limón ha sido analizado para un volumen de procesa-miento a escala industrial, a efectos de determinar la factibi-lidad económica de este procesoalternativo. / Supercritical technologies have played a key role in the search of new process alternatives for the chemical and nutraceutical industry. The supercritical fluids are considered environmentally sound solvents on the basis of theirs intrinsic properties. The public is more and more demanding with regard to the residual levels of solvents in the traditional processing of foods and pharmaceutical pro-ducts.In addition the implementation of very strict envi-ronmental regulations, has promoted the interest in super-critical technology applications. In this Thesis the econo-mic and technical feasibility of supercritical pro-cesses applied to the extraction of natural products is discussed. The work was divided in two parts, the first part compri-ses the problem of thermodynamic modeling of natural pro-ducts, derivatives and their mixtures with supercritical fluids (Chapters 1 to 4). In the second part, the problems of analysis, synthesis, simulation, optimization and de-sign applied to problems of extraction, refining and frac-tionation are considered. Chapter 1 is devoted to the ge-neral properties and applications of supercritical fluids, in connection with natural products. In Chapter 2 the high pressure phase equilibria is discussed on the basis of pha-se diagramas of binary and ternary mixtures and their extension to multicomponent mixtures. A detailed discussion of the different regions for single and multi-phase equilibria,for mixtures of alkanes, aromatic compounds, triglycerides and vegetable oils with ethane, propane and CO2 over a wide range of pressures, temperatu-res and compositions is presented. In Chapter 3 the thermodynamic modeling of phase equili-bria under super-critical conditions using recent equations of state is discussed with the purpose of selecting the more adequate modeling framework for high pressure phase equilibria of highly non ideal systems. In Chapter 4, the group contri-bution equation of state (GC-EOS) is extended to cover the systems of interest of the present Thesis. Different appro-aches are evaluated for the characteriza-tion of the natu-ral oils complex mixtures. Binary group interaction parame-ters are obtained to correlate the phase equilibrium beha-viour of a large set of binary mixtures. The correlation and prediction capability of the GC-EOS are validated against experimental data and compared with predictions obtained using otherequations of state. The Chapters 5, 6 and 7 describe the processing of different natural pro-ducts using supercritical fluid solvents. In all cases,the goal is to obtain optimum operating conditions to carry out the process with a minimum cost and satisfying the pro-ducts recovery and purity desired. Each chapter is divided in three parts: thermodynamic modeling of the systems of interest, on the basis of the results of Chapter 4, simu-lation of the process for conditions reported in pilot plant studies and optimization under different objective functions. In Chapter 5, the process of purification of vegetable oils using supercritical propane and carbon dioxide as solvents is developed and optimized. In Chapter 6 the supercritical fractionation of fish oil ethyl esters is studied and optimal schemes for the recovery and puri-fication of valuable polyunsaturated w-3 fatty acid esters are proposed. In Chapter 7, the refining of citric related essential oils is achieved by countercurrent extraction with supercritical carbon dioxide, on the basis of rigorous thermodynamic and process modeling, coupled with optimiza-tion algorithms. The optimum design for a lemon oil deter-penation process has been studied for a industrial scale plant size, with the purpose of assessing the process eco-nomic feasibility.

Não consta resumo na publicação / Abstracts not available.

Não consta resumo na publicação / Abstracts not available.

Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-02-13T14:55:17Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_ModelagemSimulacaoProcessos.pdf: 2691666 bytes, checksum: 7d7b152f8bdd96c51cda9787a6d9a5e0 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-02-15T15:00:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_ModelagemSimulacaoProcessos.pdf: 2691666 bytes, checksum: 7d7b152f8bdd96c51cda9787a6d9a5e0 (MD5) / Made available in DSpace on 2017-02-15T15:00:28Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_ModelagemSimulacaoProcessos.pdf: 2691666 bytes, checksum: 7d7b152f8bdd96c51cda9787a6d9a5e0 (MD5) Previous issue date: 2014 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho, foi elaborada uma base de dados de parâmetros de interação binária de diferentes regras de mistura, para as equações de estado de Soave-Redlich-Kwong (SRK) e Peng-Robinson (PR), a partir de dados experimentais de sistemas binários e multicomponentes de hidrocarbonetos, N2, CO2, água, β-caroteno, etanol, acetona e metanol, com objetivo de aplicar em simulações com o Aspen Hysys aos processos de fracionamento do gás natural em um processo de turbo-expansão simplificado; de fracionamento de óleo, gás e água, em separador trifásico, de extração com CO2 supercrítico de acetona de uma solução aquosa e de β-caroteno de uma solução aquosa, em coluna de multiestágios em contracorrente. De modo geral, não ocorreram diferenças significativas na predição do equilibro de fases dos sistemas binários estudados, para ambas as equações, com as regras de mistura quadrática, Mathias-Klotz-Prausnitz (MKP) com dois e três parâmetros. Cabe destacar que a regra de mistura MKP com 3 parâmetros de interação binária apresentou os menores erros absolutos para os sistemas binários de hidrocarbonetos e CO2/ hidrocarbonetos. Para os ajustes de dados de equilíbrio dos sistemas multicomponentes de hidrocarbonetos, a equação de SRK combinada com a regra de mistura quadrática com 2 parâmetros de interação binária, foi a que apresentou os menores erros médios para os sistemas ternários e para o sistema com 5 componentes em ambas as fases. No estudo de caso do separador trifásico a equação de SRK com a regra de mistura RK-Aspen foi a que apresentou a maior separação da fase aquosa de todas as simulações (285,68 kg/h) contra 256,88 kg/h para a equação SRK, 249,81 kg/h para a equação PR e 152,90 kg/h para a equação PRSV, confirmando a grande influência do uso da matriz de parâmetros de interação binária determinada neste trabalho, com destaque para os parâmetros que representam as interações entre os hidrocarbonetos com a água. Os resultados das simulações com a planta simplificada de turbo-expansão estão de acordo com a análise descrita na literatura, apresentando as seguintes taxas de recuperação de etano: 84,045% para PRSV, 84,042% para SRK, 84,039% para TST e PR e 83,98% para RKAspen. O produto final da simulação publicada na literatura para o fracionamento de uma solução aquosa de acetona utilizando o processo de extração com CO2 supercrítico consistiu na corrente de saída do fundo da coluna de destilação a 65 atm (6586 kPa), com uma composição de 67,67 % de CO2 (74,3 kg/h), 31,11% de acetona (34,15 kg/h) e 1,21% (1,33 kg/h) de água em base mássica. Na simulação com o Aspen Hysys a corrente de saída da coluna de destilação foi submetida a um conjunto de separadores flash para a separação do CO2 atingindo a recuperação de 27 kg/h de acetona em três correntes (11,14 e 15) com menos de 5 kg/h residuais de CO2 e 0,8 kg/h de água. O fracionamento da solução aquosa de β- caroteno foi simulado com o Aspen Hysys, com uma coluna de múltiplos estágios em contracorrente e um separador flash vertical para a separação do CO2. As simulações convergiram com, no mínimo, cinco estágios. Foi obtida uma corrente de fundo (produto) do separador flash com 97,83% de β-caroteno contra 89,95% em massa, para a simulação de um extrator de um único estágio publicada na literatura. / The purpose of this work was to elaborate a database of binary interaction parameters of different mixing rules, for the Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations of state, using experimental data of binary and multicomponent systems of hydrocarbons, N2, CO2, water, β-carotene, ethanol, acetone and methanol, in order to apply in simulations with the Aspen Hysys fractionation processes, of natural gas into a simplified turbo-expansion process; fractionation of oil, gas and water, in three-phase separator, supercritical CO2 extraction of acetone from an aqueous solution and β-carotene from an aqueous solution in multistage countercurrent column. In general, there were no significant differences, to both equations, in the phase equilibrium prediction of the binary systems studied, between the quadratic and Mathias-Klotz-Prausnitz (MKP) mixing rules with two and three parameters. It is worth mentioning that the MKP mixing rule with 3 binary interaction parameters presented the smallest absolute errors for hydrocarbon binary systems and CO2/hydrocarbons systems. For the settings of hydrocarbons phase equilibrium multicomponent systems data, the SRK equation combined with quadratic mixture rule with 2 binary interaction parameters, was presented the lowest average errors for ternary systems and for system with 5 components in both phases. In the case study of three-phase separator the SRK equation with the mixing rule RK-Aspen was the one that presented the greater separation of the aqueous phase of all simulations (285.68 kg/h) against 256.88 kg/h to the SRK equation, 249.81 kg/h for the PR equation and 152.90 kg/h to PRSV equation, confirming the great influence of the use the binary interaction parameters matrix determined in this work, with emphasis on the parameters that represent the interactions between the hydrocarbons with water. The results of the simulations with the simplified plant turboexpansion are according to the analysis described in the literature showing the following recovery rates of ethane: 84.045% to PRSV, 84.042% for SRK, 84.039% for TST and PR and 83.98% for RK-Aspen. The final product of the simulation published in the literature for the fractionation of an aqueous solution of acetone by using supercritical CO2 extraction process consisted in the output current from the bottom of the distillation column at 65 atm (6586 kPa), with a composition of 67.67% CO2 (74.3 kg/h), 31.11% of acetone (34.15 kg/h) and 1.21% (1.33 kg/h) of water in mass base. In the simulation with Aspen Hysys the output current of the distillation column was subjected to a set of flash separators for separation of CO2 reaching the recovery of 27 kg/h of acetone in three currents (11.14 and 15) with less than 5 kg/h CO2 waste and 0.8 kg/h of water. The fractionation of aqueous solution of β- carotene was simulated with the Aspen Hysys, with a multistage countercurrent column and a vertical flash separator for separation of CO2. The simulations have converged with a minimum of five stages. It was retrieved from an underflow (product) flash separator with 97.83% of β-carotene against 89.95% by mass for the simulation of an extractor of a single stage published in the literature.