Fluidized bed dryers are used in the pharmaceutical industry for the batch drying of pharmaceutical granulate. Maintaining optimal hydrodynamic conditions throughout the drying process is essential to product quality. Due to the complex interactions inherent in the fluidized bed drying process, mechanistic models capable of identifying these optimal modes of operation are either unavailable or limited in their capabilities. Therefore, empirical models based on experimentally generated data are relied upon to study these systems.<p> Principal Component Analysis (PCA) and Partial Least Squares (PLS) are multivariate statistical techniques that project data onto linear subspaces that are the most descriptive of variance in a dataset. By modeling data in terms of these subspaces, a more parsimonious representation of the system is possible. In this study, PCA and PLS are applied to data collected from a fluidized bed dryer containing pharmaceutical granulate. <p>System hydrodynamics were quantified in the models using high frequency pressure fluctuation measurements. These pressure fluctuations have previously been identified as a characteristic variable of hydrodynamics in fluidized bed systems. As such, contributions from the macroscale, mesoscale, and microscales of motion are encoded into the signals. A multiresolutional decomposition using a discrete wavelet transformation was used to resolve these signals into components more representative of these individual scales before modeling the data. <p>The combination of multiresolutional analysis with PCA and PLS was shown to be an effective approach for modeling the conditions in the fluidized bed dryer. In this study, datasets from both steady state and transient operation of the dryer were analyzed. The steady state dataset contained measurements made on a bed of dry granulate and the transient dataset consisted of measurements taken during the batch drying of granulate from approximately 33 wt.% moisture to 5 wt.%. Correlations involving several scales of motion were identified in both studies.<p> In the steady state study, deterministic behavior related to superficial velocity, pressure sensor position, and granulate particle size distribution was observed in PCA model parameters. It was determined that these properties could be characterized solely with the use of the high frequency pressure fluctuation data. Macroscopic hydrodynamic characteristics such as bubbling frequency and fluidization regime were identified in the low frequency components of the pressure signals and the particle scale interactions of the microscale were shown to be correlated to the highest frequency signal components. PLS models were able to characterize the effects of superficial velocity, pressure sensor position, and granulate particle size distribution in terms of the pressure signal components. Additionally, it was determined that statistical process control charts capable of monitoring the fluid bed hydrodynamics could be constructed using PCA<p>In the transient drying experiments, deterministic behaviors related to inlet air temperature, pressure sensor position, and initial bed mass were observed in PCA and PLS model parameters. The lowest frequency component of the pressure signal was found to be correlated to the overall temperature effects during the drying cycle. As in the steady state study, bubbling behavior was also observed in the low frequency components of the pressure signal. PLS was used to construct an inferential model of granulate moisture content. The model was found to be capable of predicting the moisture throughout the drying cycle. Preliminary statistical process control models were constructed to monitor the fluid bed hydrodynamics throughout the drying process. These models show promise but will require further investigation to better determine sensitivity to process upsets.<p> In addition to PCA and PLS analyses, Multiway Principal Component Analysis (MPCA) was used to model the drying process. Several key states related to the mass transfer of moisture and changes in temperature throughout the drying cycle were identified in the MPCA model parameters. It was determined that the mass transfer of moisture throughout the drying process affects all scales of motion and overshadows other hydrodynamic behaviors found in the pressure signals.

Carbon dioxide hydrates were synthesized in a 0.10m I.D. and 1.22m tall bubble column equipped with a cooling jacket for heat removal. Visual observations at different driving forces (pressures between 2.75 and 3.60 MPa and temperatures between 0 and 8ºC) were recorded with a digital camera through a sight glass of 118.8 by 15.6 mm. The superficial gas velocity was varied from 20 to 50 mm/s to attain different levels of turbulence in the liquid. The growth rate was found to be dependent on the sequence/method used to reach the operating temperature and pressure. A greater supersaturation was obtained when the system temperature and pressure were reached with very low or no bubble-induced mixing. As a result, hydrates nucleated and grew immediately when starting the gas flow with the reactor volume being quickly filled with hydrates. Moreover, the hydrate growth rate and solution final density were higher when operating conditions partially condensed CO2 resulting in greater interphase mass transfer rates. In parallel, since hydrate formation is an exothermic process and the reaction is often limited by the rate of heat removal, heat transfer measurements were achieved in a simulated hydrate environment. The instantaneous heat transfer coefficient and related statistics gave insight on the role of bubbles on heat transfer and hydrodynamics.

Fluidized bed dryers are used in the pharmaceutical industry for the batch drying of pharmaceutical granulate. Maintaining optimal hydrodynamic conditions throughout the drying process is essential to product quality. Due to the complex interactions inherent in the fluidized bed drying process, mechanistic models capable of identifying these optimal modes of operation are either unavailable or limited in their capabilities. Therefore, empirical models based on experimentally generated data are relied upon to study these systems.<p> Principal Component Analysis (PCA) and Partial Least Squares (PLS) are multivariate statistical techniques that project data onto linear subspaces that are the most descriptive of variance in a dataset. By modeling data in terms of these subspaces, a more parsimonious representation of the system is possible. In this study, PCA and PLS are applied to data collected from a fluidized bed dryer containing pharmaceutical granulate. <p>System hydrodynamics were quantified in the models using high frequency pressure fluctuation measurements. These pressure fluctuations have previously been identified as a characteristic variable of hydrodynamics in fluidized bed systems. As such, contributions from the macroscale, mesoscale, and microscales of motion are encoded into the signals. A multiresolutional decomposition using a discrete wavelet transformation was used to resolve these signals into components more representative of these individual scales before modeling the data. <p>The combination of multiresolutional analysis with PCA and PLS was shown to be an effective approach for modeling the conditions in the fluidized bed dryer. In this study, datasets from both steady state and transient operation of the dryer were analyzed. The steady state dataset contained measurements made on a bed of dry granulate and the transient dataset consisted of measurements taken during the batch drying of granulate from approximately 33 wt.% moisture to 5 wt.%. Correlations involving several scales of motion were identified in both studies.<p> In the steady state study, deterministic behavior related to superficial velocity, pressure sensor position, and granulate particle size distribution was observed in PCA model parameters. It was determined that these properties could be characterized solely with the use of the high frequency pressure fluctuation data. Macroscopic hydrodynamic characteristics such as bubbling frequency and fluidization regime were identified in the low frequency components of the pressure signals and the particle scale interactions of the microscale were shown to be correlated to the highest frequency signal components. PLS models were able to characterize the effects of superficial velocity, pressure sensor position, and granulate particle size distribution in terms of the pressure signal components. Additionally, it was determined that statistical process control charts capable of monitoring the fluid bed hydrodynamics could be constructed using PCA<p>In the transient drying experiments, deterministic behaviors related to inlet air temperature, pressure sensor position, and initial bed mass were observed in PCA and PLS model parameters. The lowest frequency component of the pressure signal was found to be correlated to the overall temperature effects during the drying cycle. As in the steady state study, bubbling behavior was also observed in the low frequency components of the pressure signal. PLS was used to construct an inferential model of granulate moisture content. The model was found to be capable of predicting the moisture throughout the drying cycle. Preliminary statistical process control models were constructed to monitor the fluid bed hydrodynamics throughout the drying process. These models show promise but will require further investigation to better determine sensitivity to process upsets.<p> In addition to PCA and PLS analyses, Multiway Principal Component Analysis (MPCA) was used to model the drying process. Several key states related to the mass transfer of moisture and changes in temperature throughout the drying cycle were identified in the MPCA model parameters. It was determined that the mass transfer of moisture throughout the drying process affects all scales of motion and overshadows other hydrodynamic behaviors found in the pressure signals.

In this study, flue gas emissions and combustion efficiencies during combustion and co-combustion of olive cake and coal are investigated in a bubbling fluidized bed with an inside diameter of 102 mm and a height of 900 mm and 1900 mm. Tun&ccedil / bilek lignite coal and Edremit olive cake were used in the experiments as fuels. Temperature distributions along the combustion column were continuously measured. Flue gas concentrations of O2, CO, SO2 and NOx were measured during combustion experiments. Four sets of experiments were performed in order to examine the effect of fuel composition, excess air ratio, freeboard extension and limestone addition on flue gas emissions and combustion efficiency. The olive cake addition to coal were 25, 50, 75 % by wt. The bed temperature on the average was 850 oC. The results of the experiments showed that coal combustion occurs at lower parts of the combustion column whereas olive cake combustion takes place more in the freeboard region. As olive cake percentage in the fuel mixture increased, CO emissions increased, SO2 and NOx emissions decreased. The reason for the decrease of NOx emissions with increasing percentage of olive cake in the fuel mixture was due to a reducing atmosphere created in the combustion column. Mostly combustion losses resulted mainly from the unburnt carbon in the fly ash. With the freeboard extension, noticeable decrease in CO emissions and slight increase in combustion efficiencies were observed. Among the limestones tested, &Ccedil / an limestone gave the best result with Ca/S = 3 at an optimum bed temperature of 850 oC. The SO2 reduction was 87% at this Ca/S ratio. For co-combustion experiments, it was observed that SO2 adsorption efficiency of limestone increased with the addition of olive cake to the fuel mixture.

Carbon dioxide hydrates were synthesized in a 0.10m I.D. and 1.22m tall bubble column equipped with a cooling jacket for heat removal. Visual observations at different driving forces (pressures between 2.75 and 3.60 MPa and temperatures between 0 and 8ºC) were recorded with a digital camera through a sight glass of 118.8 by 15.6 mm. The superficial gas velocity was varied from 20 to 50 mm/s to attain different levels of turbulence in the liquid. The growth rate was found to be dependent on the sequence/method used to reach the operating temperature and pressure. A greater supersaturation was obtained when the system temperature and pressure were reached with very low or no bubble-induced mixing. As a result, hydrates nucleated and grew immediately when starting the gas flow with the reactor volume being quickly filled with hydrates. Moreover, the hydrate growth rate and solution final density were higher when operating conditions partially condensed CO2 resulting in greater interphase mass transfer rates. In parallel, since hydrate formation is an exothermic process and the reaction is often limited by the rate of heat removal, heat transfer measurements were achieved in a simulated hydrate environment. The instantaneous heat transfer coefficient and related statistics gave insight on the role of bubbles on heat transfer and hydrodynamics.

In this study, combustion performances and emission characteristics of olive cake and olive cake+coal mixture are investigated in a bubbling fluidized bed of 102 mm inside diameter and 900 mm height. The average particle sizes of coal and olive cake used in the experiments were 1.57 mm and 1.52 mm, respectively. Flue gas concentrations of O2, CO, SO2, NOx, and total hydrocarbons (CmHn) were measured during combustion experiments. Operational parameters (excess air ratio, secondary air injection) were changed and variation of pollutant concentrations and combustion efficiency with these operational parameters were studied. The temperature profiles measured along the combustor column was found higher in the freeboard for olive cake than coal due to combustion of hydrocarbons mostly in the freeboard. The location of the maximum temperature in the freeboard shifted to the upper part of the column, as the volatile matter content in the fuel mixture increased. Combustion efficiencies in the range of 83.6-90.1% were obtained for olive cake with the excess air ratio of 1.12-2.30. The corresponding combustion efficiency for coal was 98.4-99.7% under the same conditions. As the CO and hydrocarbon concentration in the flue gas increased, the combustion efficiency decreased. Also co-combustion experiments of olive cake and coal for various mixing ratios were carried out. As the amount of olive cake in the fuel mixture increased, SO2 emissions decreased because of the very low sulfur content of olive cake. In order to increase the combustion efficiency, secondary air was injected into the freeboard which was a good solution to decrease the CO and hydrocarbon emissions, and to increase the combustion efficiency. For the setup used in this study, the optimum operating conditions with respect to NOx and SO2 emissions were found as 1.35 for excess air ratio, and 30 L/min for secondary air flowrate for the combustion of 75 wt% olive cake and 25 wt% coal mixture. Highest combustion efficiency of 99.8% was obtained with an excess air ratio of 1.7, secondary air flow rate of 40 L/min for the combustion of 25 wt% olive cake and 75 wt% coal mixture.

Bibliography: 208-218. / 339 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1989

Les eaux grises (EG) peuvent être considérées comme une ressource alternative à l’eau potable et peuvent donc être réutilisées, par exemple, pour l'arrosage d'espaces verts pour lequel une qualité ''eau destinée à la consommation humaine'' ne semble pas nécessaire. Toutefois la présence de microorganismes pathogènes et de composés organiques peut entraîner des risques sanitaires et environnementaux. Il est donc nécessaire de traiter ces EG avant de les réutiliser et caractériser les risques liés à leur recyclage, jusqu'à présent peu connus. Pour répondre à ces objectifs, la démarche a consisté à caractériser les EG afin de choisir un traitement adapté. Le procédé biologique retenu est un réacteur à lit fluidisé aérobie. Son optimisation a été basée sur l’étude de son comportement hydrodynamique et sur la cinétique de biodégradation des EG. Ses performances épuratoires ont également été déterminées. La qualité des EG traitées produites atteint les objectifs attendus par la réglementation française pour l'irrigation d'espaces verts avec des eaux usées traitées. En effet, la DCO et les MES obtenues dans l'effluent traité sont respectivement de 26 mg O2.L-1 et 5,6 mg.L-1. Le réacteur a permis de traiter 144 L.j-1 d'EG durant 16 mois. Trois parcelles de pelouse ont été irriguées respectivement par des EG brutes, des EG traitées et par de l’eau potable. Contrairement à la parcelle irriguée par les EG brutes, l'analyse de risques n'a montré aucune différence significative entre celle irriguée par les EG traitées et celle irriguée par l'eau potable. Ces travaux démontrent que les EG traitées produites dans cette étude peuvent être employées pour l’irrigation d’espaces verts. / A level of water quality intended for human consumption does not seem necessary for domestic uses such as irrigation of green spaces. Alternative water supplies like the use of greywater (GW) can thus be considered. However, GW contains pathogenic microorganisms and organic compounds which can cause environmental and health risks. As the risks related to recycling are unknown, GW treatment is necessary before reusing. To describe the risks related to GW reuses, the scientific approach performed in this study was to characterize domestic GW in order to select an appropriate treatment. The biological process chosen is an aerobic fluidized bed reactor. As this process has never been developed for GW, an optimization step based on the study of its hydrodynamic behavior and the kinetics of biodegradation of GW was performed. The treatment performances were then determined. The treated GW produced in this study reached the threshold values expected by the French regulation for irrigation of green spaces with treated wastewater. Indeed, the COD and the TSS obtained in treated GW were respectively 26 mg O2.L-1 and 5.6 mg.L-1. The fluidized bed reactor has been used to treat 144 L.d-1 of GW for 16 months. Three lawn plots were irrigated respectively with raw GW, treated GW and tap water asa reference. Contrary to the lawn plot irrigated with raw GW, the risk analysis performed in this study has shown no significant difference between the law plot irrigated with treated GW and the one irrigated with tap water. This study shows that treated GW produced from the fluidized bed reactor developed in this experiment can be used for irrigation of green spaces.

O presente trabalho refere-se ao desenvolvimento de grânulos a partir de produto seco de A. satureioides obtido por spray drying, em escala semi-industrial, visando a superar as principais limitações tecnológicas apresentadas tais como a higroscopia excessiva do produto, baixa densidade, pequeno tamanho de partícula e instabilidade dos constituintes flavonoídicos frente à luz. Dois métodos foram empregados para a granulação: granulação em leito fluidizado e granulação via seca por desagregação. Estes métodos apresentaram, respectivamente, 15 e 60 % de rendimento do processo, levando a escolha da granulação seca para a produção dos grânulos do produto seco. A granulação seca resultou em grânulos assimétricos, de faixa granulométrica situada entre 0,3 mm e 1,9 mm e de superfície irregular e rugosa. O revestimento destes grânulos foi realizado em leito fluidizado, utilizando três tipos de polímeros, Eudragit® L 30D, Opadry® II e Opadry® AMB.O rendimento médio com o Opadry® II foi de 72 %. O revestimento com Opadry® AMB foi realizado utilizando-se um baixo e alto fluxo do líquido de revestimento, obtendo-se rendimentos de 75 e 85 %, respectivamente. A higroscopia dos grânulos foi avaliada em ambientes com umidade relativa controlada de 65 ou 99 %, comparando-se o comportamento dos grânulos revestidos com o dos grânulos sem a presença de revestimento. Ambos os filmes com Opadry® não protegeram os grânulos frente à umidade. As fotomicrografias por MEV, destes grânulos, revelaram que, ambos os tipos de revestimento, apresentaram superfícies rugosas e com presença de poros explicando, parcialmente, a falta de proteção contra a umidade. O estudo da fotoproteção indica, em um primeiro momento, que o filme de revestimento promove a proteção dos flavonóides frente a ação da luz. A avaliação preliminar da liberação dos flavonóides, a partir dos grânulos, foi realizada em células de fluxo Desaga® com os grânulos sem revestimento e revestidos com Opadry® AMB. A água não demonstrou ser o meio mais favorável para este ensaio. Em meio com pH 1,2 contendo 1 % de laurilsulfato de sódio, os flavonóides quercetina, luteolina e 3-Ometilquercetina foram liberados, respectivamente, após 90 minutos, em 70, 83 e 70 % a partir dos grânulos não revestidos, e 52, 54 e 45 % a partir dos grânulos revestidos com Opadry® AMB, denotando a influência do filme de revestimento sobre o perfil de liberação dos flavonóides. Em seu conjunto, os resultados obtidos nesta primeira abordagem deste tema abrem diversas perspectivas para oaprofundamento do estudo e desenvolvimento de granulados de A. satureioides, a partir de produto seco por spray drying. / The present work was designed to develop granules from Achyrocline satureioides spray dried powders in order to overcome the main technological limitations presented by this herbal raw material: high hygroscopy, low density, small particle diameter and flavonoid sensibility against light. Two methods were employed for granulation, fluidized bed and dry granulation. These methods presented, respectively, 15 and 60 % of process yield, leading to the selection of dry granulation for preparing the granules. By this method, the granules showed 0,3 to 1,9 mm particle mean diameter, rough surface and irregular morphology. For coating the granules, three types of polymers were employed, Eudragit® L30D, Opadry® II and Opadry® AMB, in fluidized bed. The first one resulted in atomizer obstruction becoming non viable its employment. The mean yield coating obtained with Opadry® II was 72 %. The Opadry® AMB was sprayed in low and high rates yielding, respectively, 75 % and 85 %. The hygroscopicity of the granules was evaluated in controlled conditions of 65 % or 99 % RH, comparing the behavior of the coated granules which that presented by non-coated particles. Both Opadry® coatings did not protect the granules against the humidity. The SEM photomicrographis of these granules revealed that both types of coating presented rough and porous surface explaining partially, at least, the lack of protection against the humidity. The preliminary photostability assay indicated, in a first view, that the coating promotes the flavonoid protection. The flavonoid release from the granules was performed in Desaga® flow cell from the non-coated granules and from Opadry® AMB coated granules. Water demonstrated not to be an appropriate media for both tested granules. In pH 1.2 media containing 1 % of sodium lauryl sulfate, the flavonoids quercetin, luteolin and 3-O-methylquercetin were, respectively, released, after 90 minutes, in 70 %, 83 % and 70 % from non coated granules and in 52 %, 54 % and 45 % from Opadry® AMB coated granules, denoting the influence of the coating on the flavonoid release profile. Taken together, the results of this first approach openmay perspectives for more detailed studies on Achyrocline satureioides granules from the corresponding spray dried powders.

Hydrogen has been studying as an alternative energy source to replace fossil fuels. This is justified because, in its combustion is generating primarily water vapor and by its energy content is approximately 2.5 times greater than any fossil fuel. Besides these advantages, hydrogen can be produced from renewable sources, such as various types of industrial and domestic waste rich in carbohydrates. Thus, the purpose of this study was to evaluate the production of hydrogen from a substrate real, the manipueira (wastewater processing cassava), as carbon source in anaerobic fluidized bed reactor (AFBR) operated under a progressive increase in the organic loading rate (OLR). The support material for the adhesion of biomass has been expanded clay (2.8 to 3.35 mm) and the reactor was inoculated with anaerobic sludge thermal pretreatment. The reactor was operated for 164 days and gradually increasing the organic loading rate was obtained by maintaining a constant influent COD (4000 mg. L-1) throughout the operation of the reactor and varying the hydraulic retention time (HRT) of 8 to 1 hour. The production of hydrogen ranged from 0.20 to 2.04 L.h-1.L-1, when the HRT reduced from 8 h to 1 h. The yield had an increase from 0.31 to 1.91 mol H2.mol glucose-1 by reducing the HRT from 8 to 2 h. By lowering the HRT for 1 h, the yield was reduced, reaching a value of 1.20 mol H2.mol glucose-1. The soluble metabolites present during the operation of the reactor were acetic acid, butyric acid, propionic acid and ethanol. The microscopic analysis indicated the presence of bacilli, which are morphologies similar to species of the genus Clostridium sp. and Enterobacter sp., which are known as potential production of hydrogen in fermentation processes. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O hidrogênio vem sendo estudado como fonte alternativa de energia em substituição aos combustíveis fósseis. Isso porque, na sua combustão há geração principalmente de vapor de água e por seu conteúdo energético ser aproximadamente 2,5 vezes maior do que qualquer combustível fóssil. Além dessas vantagens, o hidrogênio pode ser produzido a partir de fontes renováveis, tais como os diversos tipos de resíduos industriais e domésticos ricos em carboidratos. Dessa forma, o objetivo da pesquisa foi avaliar a produção de hidrogênio a partir de um substrato real, a manipueira (água residuária do processamento da mandioca), como fonte de carbono em reator anaeróbio de leito fluidificado (RALF) operado sob aumento progressivo da taxa de carregamento orgânico (TCO). O material suporte para a aderência da biomassa foi argila expandida com diâmetro entre 2,8 3,35 mm e o reator foi inoculado com lodo anaeróbio pré-tratado termicamente. O reator foi operado por 164 dias e o aumento progressivo da taxa de carregamento orgânico foi realizado mantendo a DQO afluente constante (4000 mg. L-1) durante toda a operação do reator e variando o tempo de detenção hidráulica (TDH) de 8 horas até 1 hora. Foi constatado que a produção volumétrica de hidrogênio aumentou de 0,20 até 2,04 L.h-1.L-1, quando foi reduzido o TDH de 8 h para 1 h. E o rendimento sofreu um incremento de 0,31 até 1,91 mol H2.mol glicose-1, com a redução do TDH de 8 para 2 h. Ao reduzir o TDH para 1 h, o rendimento sofreu uma redução, atingindo o valor de 1,20 mol H2.mol glicose-1. Os metabólitos solúveis presentes durante a operação do reator foram o ácido acético, ácido butírico, ácido propiônico e etanol. As análises microscópicas indicaram a presença de bacilos, os quais são morfologias semelhantes às espécies dos gêneros Clostridium sp. e Enterobacter sp., que são conhecidas como potenciais produtoras de hidrogênio em processos fermentativos.