As part of the production of certain solid-dosage pharmaceuticals, granulated ingredients are dried in a batch fluidized bed dryer. Currently, the determination of the completion of the drying process is accomplished through measurements of product or outlet air temperatures. No quantitative measurement of hydrodynamic behaviour is employed. Changes in bed hydrodynamics caused by variations in fluidization velocity may lead to increased particle attrition. In addition, excessive desiccation of the granules caused by inaccurate determination of the drying endpoint may lead to an increase in the thermal and mechanical stresses within the granules. The activity of future high-potency or peptide based drug products may be influenced by these effects. Therefore, the quantification of hydrodynamic changes may be a key factor in the tighter control of both fluidization velocity and product moisture, which are critical for maintaining product quality. <p>High-frequency measurements of pressure fluctuations in a batch fluidized bed dryer containing pharmaceutical granulate have been used to provide a global, non-intrusive indication of the hydrodynamic changes occurring throughout the drying process. A chaotic attractor comparison statistical test known as the S-statistic, has been applied to quantify these changes in drying and a related unit operation, fluidized bed granulation. The S-statistic showed a sensitivity to moisture which is not seen with frequency and amplitude analysis. In addition, the S-statistic has been shown to be useful in identifying an undesirable bed state associated with the onset of entrainment in a bed instrumented for the collection of both pressure fluctuation and entrainment data. Thus, the use of the S-statistic analysis of pressure fluctuations may be utilized as a low-cost method for determining product moisture or changes hydrodynamic state during fluidized bed drying. <p>Electrical capacitance tomography (ECT) has also been applied in this study to image the flow structure within a batch fluidized bed used for the drying of pharmaceutical granulate. This represents the first time that ECT has been applied to a bed of wet granulate material. This was accomplished through the use of a novel dynamic correction technique which accounts for the significant reduction in electrical permittivity occurring as moisture is lost during the drying process. The correction has been independently verified using x-ray tomography. <p>Investigation of the ECT images taken in the drying bed indicates centralized bubbling behaviour for approximately the first 5 minutes of drying. This behaviour is a result of the high liquid loading of the particles at high moisture. Between moisture contents of 18-wt% and 10-wt%, the tomograms show an annular pattern of bubbling behaviour with a gradual decrease in the cross-sectional area involved in bubbling behaviour. The dynamic analysis of this voidage data with the S-statistic showed that a statistically significant change occurs during this period near the walls of the vessel, while the centre exhibits less variation in dynamic behaviour. The changes identified by the S-statistic analysis of voidage fluctuations near the wall were similar to those seen in the pressure fluctuation measurements. This indicates that the source of the changes identified by both these measurement techniques is a result of the reduction in the fraction of the bed cross-section involved in bubbling behaviour. At bed moisture contents below 5-wt%, rapid divergence was seen in the S-statistic applied to both ECT and pressure fluctuation measurements. This indicates that a rapid change in dynamics occurs near the end of the drying process. This is possibly caused by the entrainment of fines at this time, or the build-up of electrostatic charge. <p>The use of the complimentary pressure fluctuation and ECT measurement techniques have identified changes occurring as a result of the reduction of moisture during the drying process. Both the localized changes in the voidage fluctuations provided by the ECT imaging and the global changes shown by the pressure fluctuation measurements indicate significant changes in the dynamic behaviour caused by the reduction of moisture during the drying process. These measurement techniques could be utilized to provide an on-line indication of changes in hydrodynamic regime. This information may be invaluable for the future optimization of the batch drying process and accurate determination of the drying endpoint.

La tesi s’inicia fent una presentació del comportament dels llits estabilitzats magnèticament i de les seves aplicacions, així com de les limitacions que tenen degut a les pèrdues de les propietats magnètiques en certes condicions.A continuació, es proposa un model matemàtic dels llits fluïditzats estabilitzats magnèticament, basat en la distribució que segueixen les partícules amb les línies del camp. L’estabilització magnètica també s’ha aplicat a llits fluïditzats amb barreges de partícules magnètiques i no magnètiques. S’ha estudiat el comportament d’aquests sistemes, així com la influència de la fracció màssica de material magnètic en el retard en l’aparició del bombolleig. Els resultats obtinguts mostren que l’estabilització magnètica pot aplicar-se no solament a la fluïdització de partícules magnetitzables sinó també a partícules no magnetitzables, si una certa fracció de material magnètic és present en el llit. Es proposen diferents correlacions per al càlcul de la velocitat de transició en funció de les propietats del sistema gas-sòlid i les condicions d’operació.També s’estudia l’efecte del camp magnètic sobre el comportament tèrmic dels llits fluïditzats de partícules magnètiques escalfats amb una superfície calefactora introduïda dins el llit. S’ha determinat la distribució axial i radial de temperatures en el llit. A partir dels resultats experimentals, s’ha desenvolupat un model que permet el càlcul de la conductivitat tèrmica efectiva del llit. A més, mitjançant l’aplicació de l’analogia de Chilton i Colburn a les dades experimentals obtingudes, s’han proposat diferents correlacions per a l’estimació del coeficient de transferència de calor en llits estabilitzats i semi estabilitzats.Finalment, s’ha estudiat experimentalment, mitjançant l’assecament d’aire humit en llits formats per barreges d’alúmina-acer, la transferència de matèria en llits estabilitzats i semi estabilitzats. S’han emprat dos paràmetres, eficiència del llit i factor de eficiència, per comparar el comportament dels diferents tipus de llits. La precisió del model teòric desenvolupat s’ha provat amb els resultats experimentals obtinguts. Els models corresponents als llits fluïditzats clàssics no presenten un bon ajust amb les dades experimentals; ara bé, quan aquests models són modificats tenint en compte l’efecte del camp magnètic, l’ajust amb les dades és molt millor. / First, in this thesis, the behaviour of the magnetically stabilized fluidized bed is presented, as well as its applications; the limitations due to the loss of magnetic properties in certain conditions are also considered.Later, a mathematical model of the magnetically stabilized fluidized bed, based on the arrangement of particles following field lines is proposed. Magnetic stabilization has also been applied to fluidized beds with mixture of magnetisable and non-magnetisable particles. The behaviour of these systems is studied, as well as the influence of the magnetic material mass fraction on the delay of bubbling. The results obtained show that the magnetic stabilization can be applied not only to the fluidization of magnetisable materials but also to non-magnetisable particles, if a certain fraction of magnetisable material is present. Correlations are proposed to calculate the transition velocity as a function of gas-solid properties and operating conditions.Also, the effect of the magnetic field on the thermal behaviour of a fluidized bed of magnetisable particles with an immersed heating surface has been studied. The temperature distribution inside the bed has been determined, both in the radial and axial directions. A model has been developed which allows calculation of the effective thermal conductivity of the bed from experimental data. In addition, by means of the application of the Chilton and Colburn analogy to the experimental data obtained, different correlations for the estimation of the heat transfer coefficient in stabilized and semi-stabilized beds have been proposed.Finally, the mass transfer in magnetically stabilized and semi-stabilized beds has been studied experimentally using the drying of moist air in beds of alumina-steel mixtures. Two parameters, bed efficiency and efficiency factor have been used to compare the behaviour of the different beds. The accuracy of the theoretical model developed has been tested using the results obtained. The models corresponding to the classical fluidized bed do not agree with experimental data; however, when these models are modified to take into account the effect of magnetic stabilization, the accuracy is much better.

As part of the production of certain solid-dosage pharmaceuticals, granulated ingredients are dried in a batch fluidized bed dryer. Currently, the determination of the completion of the drying process is accomplished through measurements of product or outlet air temperatures. No quantitative measurement of hydrodynamic behaviour is employed. Changes in bed hydrodynamics caused by variations in fluidization velocity may lead to increased particle attrition. In addition, excessive desiccation of the granules caused by inaccurate determination of the drying endpoint may lead to an increase in the thermal and mechanical stresses within the granules. The activity of future high-potency or peptide based drug products may be influenced by these effects. Therefore, the quantification of hydrodynamic changes may be a key factor in the tighter control of both fluidization velocity and product moisture, which are critical for maintaining product quality. <p>High-frequency measurements of pressure fluctuations in a batch fluidized bed dryer containing pharmaceutical granulate have been used to provide a global, non-intrusive indication of the hydrodynamic changes occurring throughout the drying process. A chaotic attractor comparison statistical test known as the S-statistic, has been applied to quantify these changes in drying and a related unit operation, fluidized bed granulation. The S-statistic showed a sensitivity to moisture which is not seen with frequency and amplitude analysis. In addition, the S-statistic has been shown to be useful in identifying an undesirable bed state associated with the onset of entrainment in a bed instrumented for the collection of both pressure fluctuation and entrainment data. Thus, the use of the S-statistic analysis of pressure fluctuations may be utilized as a low-cost method for determining product moisture or changes hydrodynamic state during fluidized bed drying. <p>Electrical capacitance tomography (ECT) has also been applied in this study to image the flow structure within a batch fluidized bed used for the drying of pharmaceutical granulate. This represents the first time that ECT has been applied to a bed of wet granulate material. This was accomplished through the use of a novel dynamic correction technique which accounts for the significant reduction in electrical permittivity occurring as moisture is lost during the drying process. The correction has been independently verified using x-ray tomography. <p>Investigation of the ECT images taken in the drying bed indicates centralized bubbling behaviour for approximately the first 5 minutes of drying. This behaviour is a result of the high liquid loading of the particles at high moisture. Between moisture contents of 18-wt% and 10-wt%, the tomograms show an annular pattern of bubbling behaviour with a gradual decrease in the cross-sectional area involved in bubbling behaviour. The dynamic analysis of this voidage data with the S-statistic showed that a statistically significant change occurs during this period near the walls of the vessel, while the centre exhibits less variation in dynamic behaviour. The changes identified by the S-statistic analysis of voidage fluctuations near the wall were similar to those seen in the pressure fluctuation measurements. This indicates that the source of the changes identified by both these measurement techniques is a result of the reduction in the fraction of the bed cross-section involved in bubbling behaviour. At bed moisture contents below 5-wt%, rapid divergence was seen in the S-statistic applied to both ECT and pressure fluctuation measurements. This indicates that a rapid change in dynamics occurs near the end of the drying process. This is possibly caused by the entrainment of fines at this time, or the build-up of electrostatic charge. <p>The use of the complimentary pressure fluctuation and ECT measurement techniques have identified changes occurring as a result of the reduction of moisture during the drying process. Both the localized changes in the voidage fluctuations provided by the ECT imaging and the global changes shown by the pressure fluctuation measurements indicate significant changes in the dynamic behaviour caused by the reduction of moisture during the drying process. These measurement techniques could be utilized to provide an on-line indication of changes in hydrodynamic regime. This information may be invaluable for the future optimization of the batch drying process and accurate determination of the drying endpoint.

No description available.

A preservação ambiental e o uso de combustíveis fósseis para geração de energia têm estimulado a realização de pesquisas na busca de alternativas para a redução das emissões de gases poluentes como CO2, CO, SO2 e NOx. O uso da biomassa em sistemas de co-combustão em leito fluidizado é mencionado como uma destas alternativas. O presente trabalho utilizou biomassa residual da indústria de extração de tanino, o Resíduo de Cascas de Acácia Negra (RCAN), em conjunto com carvão mineral da Mina de Candiota – RS com o objetivo de estudar a fluidodinâmica entre diferentes composições destes materiais em sistema de leito fluidizado com areia em escala de laboratório e em uma unidade piloto. Também foi realizada a avaliação dos parâmetros operacionais e das emissões dos gases gerados na co-combustão das misturas em planta piloto com reator de leito fluidizado borbulhante. Durante a fluidização no sistema de escala laboratorial, os valores da velocidade mínima de fluidização, Umf, variaram consideravelmente com o aumento da concentração de RCAN no leito em relação à fluidização utilizando-se somente o carvão mineral Da mesma forma, a queda de pressão, ΔP, diminuiu com o aumento da concentração da biomassa no leito. Nas operações de co-combustão em planta piloto, as misturas de carvão mineral e RCAN necessitaram de menores porcentagens de excesso de ar (99,7% a 65,2%) no reator em comparação à queima apenas de carvão mineral (108,4% a 107,5%) para que se atingisse a temperatura de operação do leito. Em particular, a condição de maior quantidade de biomassa na alimentação pode se observar a menor porcentagem de excesso de ar (50,8%). Ainda, a co-combustão do RCAN com carvão mineral favoreceu a diminuição das concentrações de SO2 nos gases gerados em mais de 90%, mantendo as emissões em níveis aceitáveis conforme os limites de emissão estabelecidos pela resolução CONAMA Nº 436, de 22/12/2011 e Resolução SEMA Nº 016 de 2014. / The environmental issues brought by the use of fossil fuels for power generation have led to the development of research in the exploration for alternatives to reduce emissions of greenhouse gases or pollutants such as CO2, CO, SO2, and NOx. The biomass use in cofiring systems with fluidized bed has been mentioned as one of these alternatives. The present work used biomass waste from tannin extraction industry, Black Wattle Bark Waste (BWBW), jointly with coal for the purpose of studying the fluid dynamics biomass mixtures with coal and sand in different proportions of the materials in laboratory scale fluidized bed system. Also, operational parameters and emissions generated in a cofiring pilot plant with bubbling fluidized bed reactor were evaluated. The fluidization tests performed on a bench scale showed that the values of the minimum fluidization velocity, Umf, varied considerably with increasing concentration of BWBW compared with the fluidization of coal. Likewise, the pressure drop through the bed, ΔP, decreased with increasing concentration of biomass in the bed. In the cofiring operations, coal and mixtures BWBW required smaller percentages of excess air in the reactor (99,7% a 65,2%) in comparison with the pure coal (108,4% a 107,5%) burning to obtaining the bed operating temperature. The burning of the mixture with higher amounts of biomass in the reactor feed had the lowest percentage of excess air (50.8%). It was also evidenced a decrease of SO2 generation in more than 90% for the flue gas generated in the coal with BWBW cofiring keeping emissions at acceptable levels in comparison with emission limits of current legislation CONAMA Nº 436, from 22/12/2011 and legislation SEMA Nº 016 of 2014.

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Leitos fluidizados borbulhantes (LFBs) são bem conhecidos como sistemas eficientes para transferência de energia térmica em diversas aplicações industriais. Embora muitos trabalhos reportados na literatura tenham já relatado características do rendimento térmico de trocadores de calor gás-sólido em regime de LFB, evidencia-se pouca informação sobre o projeto destes sistemas voltados à sua avaliação experimental a partir do uso de técnicas de flutuações de pressão para o monitoramento do regime fluidodinâmico. Tendo em vista esta lacuna, o presente trabalho apresenta o procedimento para o dimensionamento de um trocador de calor tipo jaqueta inserido em uma coluna de leito fluidizado borbulhante construída em escala de laboratório, bem como a análise da avaliação experimental do coeficiente de transferência de calor suspensão-parede do dispositivo durante o aquecimento de água. Como garantia da operação do sistema em regime de fluidização borbulhante, incluindo ainda a exploração de condições próximas à da mínima fluidização das partículas, aplica-se o método da frequência central gaussiana como ferramenta para a detecção da desfluidização a partir de medições de flutuações de pressão. Os dados experimentais foram analisados assumindo fluxo de calor uniforme (solução de segundo tipo) ou temperatura uniforme (solução de terceiro tipo) na parede interna da jaqueta d’água. Inicialmente, testes envolvendo vazões mássicas do líquido na faixa de 1,83 ± 0,01 kg/h a 4,46 ± 0,02 kg/h, foram realizados com velocidade de fluidização na razão uo/umf igual a 4. Posteriormente, testes experimentais na vazão mássica fixa de água de 3,62 ± 0,01 kg/h, foram realizados com partículas de diâmetro médio de Sauter de 194 µm e 359 µm e com ar de fluidização alimentado em razões uo/umf de 0,5 a 4,0. Em todos os ensaios deste estudo, o regime de escoamento da água na região anular do trocador de calor foi caracterizado como laminar e termicamente em desenvolvimento. Os resultados apontaram uma variação no coeficiente de transferência de calor suspensão-parede na faixa de 169,93 ± 7,52 W/m²K a 353,28 ± 29,78 W/m²K para solução de segundo tipo, e de 191,54 ± 8,55 W/m²K a 468,43 ± 39,27 W/m²K para solução de terceiro tipo, ao utilizar temperaturas do leito de 50 ºC e 70 ºC. A análise dos dados obtidos confirma que o uso das partículas mais finas e temperaturas maiores do leito promovem o incremento no valor do coeficiente de transferência de calor suspensão-parede. Adicionalmente, os resultados verificaram a presença de um valor máximo do coeficiente de transferência de calor suspensão-parede na faixa de uo/umf analisada. / Bubbling fluidized beds (BFBs) are well known as efficient systems for thermal energy transfer in several industrial applications. Although many works have already pointed out the performance features of gas-solid BFB heat exchangers, more data about the design and operation of these devices are needed when using pressure fluctuation techniques for the hydrodynamics control. Considering this gap, the procedure for the design of a jacket-type heat exchanger placed in a bench scale bubbling fluidized bed column and the experimental assessment of its bed-to-wall heat transfer coefficient under several operating conditions are presented here. As a guarantee for operating the system under a bubbling fluidization regime, as well as in conditions close to the minimum fluidization, the central Gaussian frequency method is applied. By using this method, it is possible to identify the defluidization phenomenon from pressure fluctuations measurements. The experimental information was analyzed assuming uniform heat flux (solution of second type) or uniform temperature (solution of third type) in the inner wall of the water jacket. Initial tests were performed at fluidization velocity uo/umf ratio equal to 4, involving water mass flow rates in the range of 1.83 ± 0.01 kg/h to 4.46 ± 0.02 kg/h. Other experimental tests, this time involving water mass flow rate kept constant at 3.62 ± 0.01 kg/h, were carried out with particles of 194 and 359 μm in Sauter mean diameter and with fluidization air fed in uo/umf ratios changing from 0.5 to 4.0. In all tests of this study, the water flow regime in the annular region of the heat exchanger was identified as laminar and thermally developing. Results indicated that the bed-to-wall heat transfer coefficient varies in the range of 169.93 ± 7.52 W/m²K to 353.28 ± 29.78 W/m²K for the second type solution and from 191.54 ± 8.55 W/m²K to 468.43 ± 39.27 W/m²K for the third type solution, when using bed temperatures of 50 °C and 70 °C. The analysis of these results confirms that by using the finer particle or the higher bed temperature, the value of the bed-to-wall heat transfer coefficient tends to increase. In addition, results suggested that a maximum value of the bed-to-wall heat transfer coefficient can be obtained in the range of uo/umf ratio tested, which is in agree with previous works.

Leitos fluidizados borbulhantes (LFBs) são bem conhecidos como sistemas eficientes para transferência de energia térmica em diversas aplicações industriais. Embora muitos trabalhos reportados na literatura tenham já relatado características do rendimento térmico de trocadores de calor gás-sólido em regime de LFB, evidencia-se pouca informação sobre o projeto destes sistemas voltados à sua avaliação experimental a partir do uso de técnicas de flutuações de pressão para o monitoramento do regime fluidodinâmico. Tendo em vista esta lacuna, o presente trabalho apresenta o procedimento para o dimensionamento de um trocador de calor tipo jaqueta inserido em uma coluna de leito fluidizado borbulhante construída em escala de laboratório, bem como a análise da avaliação experimental do coeficiente de transferência de calor suspensão-parede do dispositivo durante o aquecimento de água. Como garantia da operação do sistema em regime de fluidização borbulhante, incluindo ainda a exploração de condições próximas à da mínima fluidização das partículas, aplica-se o método da frequência central gaussiana como ferramenta para a detecção da desfluidização a partir de medições de flutuações de pressão. Os dados experimentais foram analisados assumindo fluxo de calor uniforme (solução de segundo tipo) ou temperatura uniforme (solução de terceiro tipo) na parede interna da jaqueta d’água. Inicialmente, testes envolvendo vazões mássicas do líquido na faixa de 1,83 ± 0,01 kg/h a 4,46 ± 0,02 kg/h, foram realizados com velocidade de fluidização na razão uo/umf igual a 4. Posteriormente, testes experimentais na vazão mássica fixa de água de 3,62 ± 0,01 kg/h, foram realizados com partículas de diâmetro médio de Sauter de 194 µm e 359 µm e com ar de fluidização alimentado em razões uo/umf de 0,5 a 4,0. Em todos os ensaios deste estudo, o regime de escoamento da água na região anular do trocador de calor foi caracterizado como laminar e termicamente em desenvolvimento. Os resultados apontaram uma variação no coeficiente de transferência de calor suspensão-parede na faixa de 169,93 ± 7,52 W/m²K a 353,28 ± 29,78 W/m²K para solução de segundo tipo, e de 191,54 ± 8,55 W/m²K a 468,43 ± 39,27 W/m²K para solução de terceiro tipo, ao utilizar temperaturas do leito de 50 ºC e 70 ºC. A análise dos dados obtidos confirma que o uso das partículas mais finas e temperaturas maiores do leito promovem o incremento no valor do coeficiente de transferência de calor suspensão-parede. Adicionalmente, os resultados verificaram a presença de um valor máximo do coeficiente de transferência de calor suspensão-parede na faixa de uo/umf analisada. / Bubbling fluidized beds (BFBs) are well known as efficient systems for thermal energy transfer in several industrial applications. Although many works have already pointed out the performance features of gas-solid BFB heat exchangers, more data about the design and operation of these devices are needed when using pressure fluctuation techniques for the hydrodynamics control. Considering this gap, the procedure for the design of a jacket-type heat exchanger placed in a bench scale bubbling fluidized bed column and the experimental assessment of its bed-to-wall heat transfer coefficient under several operating conditions are presented here. As a guarantee for operating the system under a bubbling fluidization regime, as well as in conditions close to the minimum fluidization, the central Gaussian frequency method is applied. By using this method, it is possible to identify the defluidization phenomenon from pressure fluctuations measurements. The experimental information was analyzed assuming uniform heat flux (solution of second type) or uniform temperature (solution of third type) in the inner wall of the water jacket. Initial tests were performed at fluidization velocity uo/umf ratio equal to 4, involving water mass flow rates in the range of 1.83 ± 0.01 kg/h to 4.46 ± 0.02 kg/h. Other experimental tests, this time involving water mass flow rate kept constant at 3.62 ± 0.01 kg/h, were carried out with particles of 194 and 359 μm in Sauter mean diameter and with fluidization air fed in uo/umf ratios changing from 0.5 to 4.0. In all tests of this study, the water flow regime in the annular region of the heat exchanger was identified as laminar and thermally developing. Results indicated that the bed-to-wall heat transfer coefficient varies in the range of 169.93 ± 7.52 W/m²K to 353.28 ± 29.78 W/m²K for the second type solution and from 191.54 ± 8.55 W/m²K to 468.43 ± 39.27 W/m²K for the third type solution, when using bed temperatures of 50 °C and 70 °C. The analysis of these results confirms that by using the finer particle or the higher bed temperature, the value of the bed-to-wall heat transfer coefficient tends to increase. In addition, results suggested that a maximum value of the bed-to-wall heat transfer coefficient can be obtained in the range of uo/umf ratio tested, which is in agree with previous works.

Brazil holds second place in world production of dicalcium phosphate, which represents the main source of phosphorus for complementing the mineral salt that makes up the daily feed for cattle, hogs and fowls. Considering the fact that the increase in consumption of phosphates due to the increased annual consumption of meat by the world population, development of the technology necessary to guarantee quality and productivity has become imperative in order to supply this competitive market. The requirement for BUNGE Fertilizantes S.A. to accompany the world trend, reflected by client suggestions for sales of bulk quantities, originated the search for a new technology to produce microgranulated dicalcium phosphate. Due to characteristics adverse to forming the microgranulated dicalcium phosphate grain (particle size, monocalcium phosphate and residual acidity), it has become necessary to apply a final product classification process to guarantee compliance with the physical specifications of the material at the moment of expediting to clients. The purpose of this dissertation is to perform a study of the classification system used for fluidization, seeking scale-up information for construction of an industrial unit to be installed at the Cajati Facilities of BUNGE Fertilizantes. Fluidization is utilized commercially in a wide range of processes such as: catalytic operations, cooling, drying, recovery, etc, it utilizes the elutriation effect in wich the relatively small components are entrained by the gas flow for physical classification of materials. Within this concept an effort was made to quantify the effects of operational and dimensional variables of the fluidized bed system: porosity of the distribuition screen, residence time and freeboard angle. In accordance with the main experimental results, a statistical analyses was made by multiple regression, thus obtaining parameters related to the isolated variables and the interactions among them. It was observed that the operational and dimensional conditions that promote the best Separation and Recovery efficiencies for the system were those for which the screen porosity was 11 %, the residence time was 5,34 minutes and the freeboard angle was 33,62o. On the basis of the optimum data obtained from the fluidization pilot system, an industrial system was designed for the Cajati Facilities, having classification capacity of microgranulated dicalcium phosphate of 100 Tons/h. The resultant Separation end Recovery efficiencies of the industrial system demonstrate an excellent application of technology for FBC (dicalcium phosphate) classification and the model obtained from the pilot project precisely predicts the efficiencies for industrial systems. Thus, the mathematic model obtained from the pilot plant can be used as a reference for design and scale-up of microgranulated dicalcium phosphate industrial classification units, having characteristics similar to those studied in this dissertation. / O Brasil ocupa o segundo lugar na produção de fosfato bicálcico, principal fonte de fósforo para complementação do sal mineral que integra a ração diária dos animais (bovinos, suínos e aves). Levando-se em consideração o crescimento do consumo de fósforo em decorrência do aumento anual do consumo de carne pela população mundial, torna-se imperativo o desenvolvimento de tecnologia para garantir qualidade e produtividade, visando atender a este mercado cada vez mais competitivo. A busca de uma nova tecnologia para a produção de fosfato bicálcico microgranulado originou-se da necessidade da BUNGE Fertilizantes S.A. acompanhar uma tendência mundial atendendo às sugestões de clientes para a venda a granel. Devido às características adversas para uma boa formação do grão do fosfato bicálcico microgranulado (diâmetro da partícula, fosfato monocálcico e acidez residual) faz-se necessário a aplicação de um processo de classificação do produto final para garantir o atendimento às especificações físicas do material no momento da expedição para os clientes. O objetivo deste trabalho é estudar um sistema de separação utilizando a fluidização, buscando informações de scale-up para o dimensionamento de uma unidade industrial a ser instalada no Complexo Industrial de Cajati da BUNGE Fertilizantes. A fluidização é usada comercialmente em uma grande variedade de processos, tais como: operações catalíticas, resfriamento, secagem, recobrimento, etc, e utiliza o efeito da elutriação, onde os componentes relativamente pequenos são arrastados pelo fluxo de gás, para a separação física dos materiais. Dentro deste conceito, busca-se quantificar os efeitos das variáveis operacionais e dimensionais de um sistema leito fluidizado: porosidade da placa distribuidora, tempo de residência e ângulo da zona de expansão. Conforme os principais resultados experimentais, foi feita uma análise estatística através de regressão múltipla obtendo-se os parâmetros relacionados às variáveis isoladas e interações entre elas. Observou-se que as condições operacionais e dimensionais que atingem as melhores eficiências de Separação e Recuperação para o sistema foram aquelas nas quais a porosidade da placa era de 11 %, o tempo de residência do material no leito de 5,34 minutos e o ângulo da zona de expansão (freeboard) de 33,62º. A partir dos dados ótimos obtidos no sistema piloto de fluidização foi dimensionado um sistema industrial para a Unidade da Bunge Fertilizantes em Cajati com capacidade de classificar 100 T/h de fosfato bicálcico microgranulado. Os resultados das eficiências de Separação e Recuperação do sistema industrial demonstram a excelente aplicação da tecnologia para classificação do FBC (fosfato bicálcico), e o modelo obtido no sistema piloto prevê, com uma boa precisão, as eficiências para sistemas industriais. Desta forma o modelo matemático levantado para o sistema piloto de leito fluidizado pode ser usado como referência para o dimensionamento ( scale-up ) de unidades industriais de classificação de fosfato bicálcico microgranulado, com características semelhantes ao estudado neste trabalho. / Mestre em Engenharia Química

A preservação ambiental e o uso de combustíveis fósseis para geração de energia têm estimulado a realização de pesquisas na busca de alternativas para a redução das emissões de gases poluentes como CO2, CO, SO2 e NOx. O uso da biomassa em sistemas de co-combustão em leito fluidizado é mencionado como uma destas alternativas. O presente trabalho utilizou biomassa residual da indústria de extração de tanino, o Resíduo de Cascas de Acácia Negra (RCAN), em conjunto com carvão mineral da Mina de Candiota – RS com o objetivo de estudar a fluidodinâmica entre diferentes composições destes materiais em sistema de leito fluidizado com areia em escala de laboratório e em uma unidade piloto. Também foi realizada a avaliação dos parâmetros operacionais e das emissões dos gases gerados na co-combustão das misturas em planta piloto com reator de leito fluidizado borbulhante. Durante a fluidização no sistema de escala laboratorial, os valores da velocidade mínima de fluidização, Umf, variaram consideravelmente com o aumento da concentração de RCAN no leito em relação à fluidização utilizando-se somente o carvão mineral Da mesma forma, a queda de pressão, ΔP, diminuiu com o aumento da concentração da biomassa no leito. Nas operações de co-combustão em planta piloto, as misturas de carvão mineral e RCAN necessitaram de menores porcentagens de excesso de ar (99,7% a 65,2%) no reator em comparação à queima apenas de carvão mineral (108,4% a 107,5%) para que se atingisse a temperatura de operação do leito. Em particular, a condição de maior quantidade de biomassa na alimentação pode se observar a menor porcentagem de excesso de ar (50,8%). Ainda, a co-combustão do RCAN com carvão mineral favoreceu a diminuição das concentrações de SO2 nos gases gerados em mais de 90%, mantendo as emissões em níveis aceitáveis conforme os limites de emissão estabelecidos pela resolução CONAMA Nº 436, de 22/12/2011 e Resolução SEMA Nº 016 de 2014. / The environmental issues brought by the use of fossil fuels for power generation have led to the development of research in the exploration for alternatives to reduce emissions of greenhouse gases or pollutants such as CO2, CO, SO2, and NOx. The biomass use in cofiring systems with fluidized bed has been mentioned as one of these alternatives. The present work used biomass waste from tannin extraction industry, Black Wattle Bark Waste (BWBW), jointly with coal for the purpose of studying the fluid dynamics biomass mixtures with coal and sand in different proportions of the materials in laboratory scale fluidized bed system. Also, operational parameters and emissions generated in a cofiring pilot plant with bubbling fluidized bed reactor were evaluated. The fluidization tests performed on a bench scale showed that the values of the minimum fluidization velocity, Umf, varied considerably with increasing concentration of BWBW compared with the fluidization of coal. Likewise, the pressure drop through the bed, ΔP, decreased with increasing concentration of biomass in the bed. In the cofiring operations, coal and mixtures BWBW required smaller percentages of excess air in the reactor (99,7% a 65,2%) in comparison with the pure coal (108,4% a 107,5%) burning to obtaining the bed operating temperature. The burning of the mixture with higher amounts of biomass in the reactor feed had the lowest percentage of excess air (50.8%). It was also evidenced a decrease of SO2 generation in more than 90% for the flue gas generated in the coal with BWBW cofiring keeping emissions at acceptable levels in comparison with emission limits of current legislation CONAMA Nº 436, from 22/12/2011 and legislation SEMA Nº 016 of 2014.