Green chemistry principles have been applied to the enhancement of two industrial chemistry problems. An industrially used reaction to form alcohols from aldehydes and ketones, the Meerwein-Ponndorf-Verley reduction, was improved by introducing a new catalyst Al(OtBu)₃. Due to the lower state of aggregation of this catalyst versus the conventional Al(OiPr)₃ catalyst, reduction rates were found to be faster in both pure iPrOH and mixed solvent systems for three model compounds: benzaldehyde, acetophenone, and a complex, chiral ketone, (S)-CMK. This allowed for the successful implementation of two important milestones; lowering the amount of catalyst needed necessary to complete the reactions (an economic benefit and lower waste) and the conversion from traditional batch reactions to continuous flow (a processing benefit) whereby reactions can be scaled-out rather than scaled-up. Another industrially important field of research that was focused on was CO₂ capture. High energy demands from current CO₂ capture methods such as aqueous amine solvents, specifically from coal-fired power plant flue gas, led to the development of non-aqueous reversible ionic liquids based on silylated amines. Structural modifications of the substitution around the silicon atom, the length of the alkyl chain bonding the silicon and amine, branching along the alkyl backbone, and investigating secondary and primary amines within this class of silylated amines were completed. These amines were reacted with CO₂ and the CO₂ capacity, the ionic liquid viscosity, reversal temperature and reaction enthalpy were all considered as a function of structure. In all cases the capacity was found to be not only greater than that of monethanolamine, an industrial standard, but higher than theoretical predictions through the formation of carbamic acid. Viscosity, reversal temperature, and reaction enthalpy were all found to be tunable through structure. These modifications gave significant insight into the necessary direction for optimization of these solvents as energy-efficient replacements of current CO₂ capture technology.

The current trend in the pharmaceutical industry is towards continuous flow processes. Continuous flow reactor technology can produce a cheaper, better quality product at reduced energy and environmental cost through more efficient mass and heat transfer. It also enables a simplified and faster approach to bulk production by scaling out as opposed to scaling up. The research presented here focuses on the configuration and installation of a continuous flow system into the laboratory, and the transfer of a Meerwein-Ponndorf-Verley (MPV) reduction from batch to continuous mode. The Corning® glass continuous flow reactor in our laboratory utilizes specially-designed mixing structures for enhanced mass transfer. Additionally, the glass reactor offers nonreactivity and corrosion resistance over a wide range of temperature and pressure, which conventional steel reactors do not allow. The MPV reduction is a well-known method to prepare primary and secondary alcohols from aldehydes and ketones, respectively. The traditional MPV reduction protocol (Al(OiPr)₃ in isopropanol) was modified to enable the technological transfer from batch to continuous mode. This is the first time MPV reduction reactions were carried out in continuous mode. As a result, the MPV reduction of the model compound, benzaldehyde, was successfully conducted with 60% less catalyst and product yield was improved up to 20% (average of 10%) in continuous flow reactions as compared to current batch technology. These results are being used to develop a technology roadmap for the pharmaceutical industry to implement continuous flow processes in their manufacturing operations.

An introduction is given to the background theory and scientific literature of the major subject areas of interest in this thesis, namely the chemistry of free radical and anionic polymerisation, molecular weight control in each type of polymerisation, polymerisation reactors, computer simulation of polymerisation processes and polymer characterisation by gel permeation chromatography. A novel computer model has been devised, based on the analysis of the polymerisation process in terms of the reaction extent of each reactant and the use of generation functions to describe the concentration of living and dead polymeric species, for the free radical, solution polymerisation of methylmethacrylate in a CSTR. Both heat and mass balance expressions have been described. Conversion, Mn and Mw were monitored. To test the model a reactor was designed and constructed. A detailed description of the reactor and the experimental conditions used for the validation of the model are given. The results of these studies are presented and excellent agreement is shown between model predictions and experiments up to 30% conversion for Mn w and % conversion. A similar study is described for the anionic polymerisation of styrene in tetrahydrofuran as solvent, in a CSTR. In this work the computer model becomes 'stiff' when realistic rate constants are introduced in the kinetic expressions. Experimental difficulties were encountered in obtaining reproducible results in the anionic work. A new approach of using 'scavengers' as protecting agents for the living chains is described. A scavenger was successfully employed in the preparation of block copolymers using a tubular reactor. Block copolymerisation, in addition to providing a means of checking the number of the 'living' chains inside the reactor, is of interest in its own right. All the experimental findings are discussed in relation to the currently accepted views found in the scientific literature.

The separation of the expensive catalysts from the solvent and reaction products remains one of the major disadvantages of homogeneous catalytic reactions, which are otherwise advantageous because of their high activity, tuneable selectivity and ease of study. Ideally, the homogeneous reactions would be carried out in continuous flow mode with the catalyst remaining in the reactor at all times, whilst the substrates and products flow over the catalyst. The system we have been studying is one where the catalyst is dissolved in a thin film of an ionic liquid, and this is supported within the pores of a microporous silica. This supported ionic liquid phase (SILP) catalyst is then placed in a tubular flow reactor, similar to that used for heterogeneous reactions. The raw materials are then injected into the rig, pass through the reactor and the products and the raw materials that have not reacted are collected at the other end of the rig. Supercritical CO₂ is used to transport the raw materials and products along the catalyst bed, allowing a continuous flow mode with low leaching for both the catalyst and the ionic liquid. We have applied this procedure first to alkene metathesis catalysed by a ruthenium complex that has been especially designed to dissolve in 1-butyl-3-methyimidazolium triflamide (BMIM NTf₂), which was used as ionic liquid. Activity is observed for the ring closing metathesis of diethyl 2,2-diallylmalonate, but the catalyst is not stable, only allowing about 300 turnovers. This instability is attributed to the formation of Ru=CH₂ moieties, which dimerise to an inactive species. More success is achieved with internal alkenes such as 2-octene and especially methyl oleate. Self metathesis of methyl oleate continues for >10.000 turnovers over 10 h, with only small decreases in activity. The cross metathesis of methyl oleate with dimethyl maleate has also been studied. Cross metathesis dominates in the early stages of the reaction but the cross metathesis products diminish with time. Surprisingly, the catalyst does not deactivate since self metathesis of methyl oleate continues. The phase behaviour of the reaction was monitored and gave us an insight into the reasons for this change in selectivity. Methoxycarbonylation reactions in continuous flow proved to be a much more difficult process than the previous metathesis reactions. Higher catalyst loading was needed to reduce the reaction times. The first continuous flow reactions showed conversion predominantly, if not exclusive, of 1-octene isomerised products. The presence of ionic liquid (IL) in the SILP system was essential, otherwise the catalyst leached out of the reactor very quickly. Batch reactions showed that none of the studied parameters (absence of presence of either BMIM NTf₂, OMIM NTf₂, silica or CO₂) had any influence on the reaction, but when observing the results it was noticed that the reactions that gave the best results were performed in a close range of pressures between 55 and 70 bar, indicating that the reaction might be pressure dependent. Further continuous flow reactions in that range of pressures gave the best conversions to methoxycarbonylation products. Unfortunately, at these pressures and without CO₂ the reaction took place in a liquid phase and thus substantial IL and catalyst leaching was observed, causing a decrease in conversion and making the reaction not feasible under continuous flow conditions. Nevertheless, the catalyst system composed of Pd, 1,2-bis(di-tert-butylphosphinomethyl)benzene (DTBPMB) ligand and acid showed an excellent linear selectivity, usually higher than 90%, both in batch and continuous flow reactions. Hydrogenation reactions of dimethyl itaconate (DMI) and dibutyl itaconate (DBI) using Rh-MeDuPhos showed excellent activity and enantioselestivity in a batch mode. In a continuous flow mode IL leaching caused a decrease of the enantioselectivity. The best results were obtained when CO₂ was not present. On the other hand, the absence of CO₂ implied that the reaction was performed in a liquid phase and therefore abundant IL leaching was observed along with a decrease in the enantioselectivity. A study of the reaction behaviour when using CO₂ in its different phases (liquid, gas and supercritical) was carried out. Under supercritical conditions IL leaching was avoided but conversion was not observed. When using CO₂ in its liquid phase some conversion was observed and full conversion occurred in its gas phase, but abundant IL leaching caused a decrease in the enantioselectivity. Better results were obtained by immobilising a Rh-MeDuPhos catalyst onto alumina via heteropoly acids. The effect of pressure, H₂ flow and substrate flow were studied and the stability of the reaction in the long term was examined under optimal conditions. More than 12,900 TONs were achieved after 4 days of continuous reaction, with conversions higher than 90% during the 3 first days and e.e. higher than 99% during the 2 first days.

This thesis showcases a work that focused on developing processes with improved economic and environmental signatures. It illustrates the strengths of chemists and chemical engineers working together towards sustainable solutions. The joint collaboration between Drs. Liotta and Eckert allows the combination of disciplines to overcome economic and environment obstacles. This thesis depicts the application of chemical engineering and chemistry for industrial processes towards reducing cost and environmental impact. In chapter 2, a synthetic sequence yielding a pharmaceutical precursor was optimized for continuous processing. The precursor was for the pharmaceutical drug Ro 31-8959, which acts as a human immunodeficiency virus (HIV) protease inhibitor. A continuous flow reactor was designed, built and utilized successfully for the two-step reaction of the diazoketone pharmaceutical precursor, (1-benzyl-3-chloro-2-hydroxy-propyl)-carbamic acid tert-butyl ester. The best configuration for the continuous flow reactor involved a single and double coiled stainless steel reactor packed with glass beads. The yield obtained for the diazoketone was quantitative. In chapter 3, the cleavable surfactant (cleavable surfactants decompose in non-surface active ingredients upon stimulus), n-octyl thiirane oxide was synthesized, characterized and its surface activity and loss of surface activity upon heating was demonstrated. The n-octyl thiirane oxide surfactant activity was measured using a dye, Suddan III, and compared to a commercially available surfactant sodium dodecyl sulfate. In chapter 4, 5-amino-1H-tetrazole was synthesized using two novel synthetic routes starting from benign chemicals. Both routes involved Sharpless click chemistry in the first step to form the tetrazole ring. Both routes also used hydrogen transfer as the last step for the formation of the 5-amino-1H-tetrazole. These syntheses eliminated the use of highly toxic and/or explosive chemicals such as cyanamide, hydrazoic acid, and hydrazine. Finally in chapter 5, phase transfer catalysis was used as a means to improve reaction rates and yields between a siloxylated reagent (in the liquid phase) and insoluble ionic reagents (in the solid phase). The activity of commercial phase transfer catalysts like tetra-n-butylammonium bromide was compared to the activity of two novel custom-made siloxylated phase transfer catalysts. Surprisingly, the tetra-n-butylammonium resulted in superior rate constants to the custom made siloxylated phase transfer catalysts.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Diante dos avanços tecnológicos, pesquisadores têm intensificado a busca por métodos de remoção de metais, que tragam bons resultados de captação a partir de efluentes contaminados, aliados a um baixo custo. A utilização de materiais biológicos como algas marinhas, fungos e bactérias vem se destacando e se tornando uma solução atrativa quando comparados com os tratamentos químicos convencionais; essa técnica é denominada biossorção. A biossorção é um processo de captação de íons metálicos de uma solução, a partir de interações entre o metal e determinados sítios ativos presentes na parede celular da biomassa. Existe também um crescente interesse pelo estudo dos elementos de terras raras (TR) por possuirem alto valor agregado, acarretado por processos caros e de alta complexidade na sua separação e purificação. Desta forma, este trabalho teve como objetivo descrever o potencial de biossorção de lantânio - um representante dos TR - pela macroalga Sargassum sp., a partir de soluções aquosas. Para isso foram realizados estudos em batelada, aplicando modelos cinéticos e de equilíbrio, e estudos em regime contínuo de biossorção dos íons de lantânio (III), além de um sistema contínuo bimetálico, no qual houve a adição do metal cério, outro TR. As determinações analíticas foram realizadas por espectrometria de emissão ótica por plasma indutivamente acoplado. Os ensaios cinéticos foram realizados nas concentrações metálicas de 10 e 100 mg.L-1 e em duas concentrações distintas de biomassa 2 e 5 g.L-1 na temperatura de 301C. Dois modelos cinéticos foram testados, pseudo-primeira ordem e segunda ordem, tendo o modelo de segunda ordem apresentado melhor ajuste dos dados, com r2 igual a 0,9697. No ensaio de equilíbrio foi construída a isoterma que apresentou um perfil crescente na captação no entanto não alcançou a remoção máxima. Os modelos de Langmuir e Freundlich foram utilizados para ajustar os dados da isoterma, sendo verificado maior correlação dos dados com o modelo de Langmuir; resultando num valor de captação máxima calculado pelo modelo de 3,55 mmol.g-1. No ensaio dinâmico foram realizados dois experimentos, 1 e 2. O Experimento 1 foi realizado com três colunas interligadas e recheadas com 20g de biomassa cada, sendo bombeada uma solução aquosa de lantânio na concentração de 1,41mmol.L-1. O Experimento 2 foi constituido de uma solução contendo lantânio e cério ambos na mesma concentração anterior de 1,41 mmol.L-1, sendo bombeada somente para uma única coluna recheada com 20g de biomassa. Os resultados demonstraram que o ponto de saturação não foi atingido dentro das 8 horas em que se deu o processo, o que indica a alta afinidade da Sargassum sp. pelo lantânio e que a presença do cério associada a redução da vazão prejudicou a captação do lantânio / Considering the utmost technological advances, researchers have intensified the searching for a new methodology on removing metals from wastewaters that can provide adequate outcomes as far as the metal uptake is concerned, allied with cost effectiveness of the process. The use of organic materials such as algae, fungi and bacteria has been highlighting and is becoming to be considered an interesting solution when compared to conventional chemical treatments. This technique is called biosorption, which is a process that captures metal ions from a solution, based on the interactions between metals and active groups present on the cell wall of the biomass. The interest on the application of this technique is growing and studies about the maximum concentration that can be discharged in the environment without harmful consequences and for the separation and recovery of rare-earth (RE) elements are being done. In this work, it was used the biomass Sargassum sp. as biosorbent in Lanthanum biosorption process. It was performed kinetic, equilibrium and continuous studies of biosorption of lanthanum ions (III) by means of a bimetallic continuous system, to which there was the addition of Cerium metal, another element of the RE. Analytical determinations were performed by inductively coupled plasma optical emission spectrometry. Kinetic experiments were performed at constant temperature of 30 1 C, metal concentrations of 10 and 100 mg.L-1 and at two different concentrations of biomass 2 and 5 g.L-1. Two kinetic models were tested, pseudo-first order and second order, and a comparison of the best fit was made from the second-order model with r2 equal to 0.9697. In the equilibrium experiment the isotherm was obtained with a rising profile in the capture, without reaching the maximum removal. The Langmuir and Freundlich models were used to help to fit the data of the isotherm, being the Langmuir model the one presenting greater correlation, with a maximum uptake value of 3.55 mmol.g-1. In the dynamic test, two experiments were conducted. Test 1 was conducted with three interconnected columns filled with 20g of biomass each, pumped the Lanthanum solution. Test 2 was made from Lanthanum solution and Cerium pumped for column with 20g of biomass. The results showed that the saturation point was not achieved in the 8h of the experiment, which indicates the high affinity of Sargassum sp by Lanthanum and that the presence of Cerium as well as flow reduction impaired the uptake of Lanthanum

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Adaptada dos conceitos da produção enxuta, a construção enxuta é uma filosofia de gestão da produção voltada à construção civil. Dos cinco princípios enxutos em que se baseia, o que mais tem se estudado desde a publicação do Relatório Técnico n72 Aplicação da Nova Filosofia de Produção à Construção (publicado pelo CIFE Center for Integrated Facility Engineering, ligado à Universidade de Stanford, EUA) é o Fluxo Contínuo. A idéia de manter o fluxo contínuo está diretamente ligada à continuidade da produtividade, ou seja, manter a produtividade em uma taxa constante. Aplicar o conceito enxuto de fluxo contínuo através da manutenção das taxas de produtividade significa gerenciar o empreendimento de modo que a execução das atividades se mantenha de acordo com os parâmetros estabelecidos durante a fase de planejamento. Por meio de ferramentas enxutas de gerenciamento é feita a simulação em Excel de três atividades pertencentes ao processo de execução de lajes prediais de edifícios construídos em estruturas metálicas: steel deck, armação e concretagem. A elaboração da planilha possibilita a avaliação das perdas ocorridas durante a execução das atividades sob a ótica do conceito de atrasos e esperas. A soma destas perdas resulta ainda em dois efeitos distintos considerados como perdas acumuladas e perdas compensadas, proporcionando ao gerente do empreendimento dados consistentes para traçar estratégicas para eliminação do desperdício ou uma antevisão dos desperdícios que podem estar associados à execução das atividades se estas forem mal planejadas. / Adapted from the concepts of lean production, lean construction is a management philosophy of the production directed to construction. Of the five lean principles what else has been studied since the publication of Technical Report No. 72 - Application of New Production Philosophy to Construction (published by CIFE - Center for Integrated Facility Engineering, connected to Stanford University, USA) is the continuous flow. The idea of maintaining the continuous flow is directly linked to continued productivity, ie keep productivity at a constant rate. Apply the concept of lean stream by maintaining productivity rates means managing the project so that the execution of activities is maintained in accordance with the guidelines established during the planning phase. Through lean management tools is done in Excel simulation of three activities from the implementation process of building slabs of buildings constructed in steel structures, steel deck, frame and concrete. The elaboration of the sheet allows the evaluation of the losses occurred during the execution of activities from the perspective of the concept of delays and waits. The total of these losses still result in two distinct effects considered to accumulated losses and offset losses, providing the manager of the project consistent data to plot strategy for disposal of waste or a preview of wastes that may be associated with the implementation of the activities if they are badly planned.

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Diante dos avanços tecnológicos, pesquisadores têm intensificado a busca por métodos de remoção de metais, que tragam bons resultados de captação a partir de efluentes contaminados, aliados a um baixo custo. A utilização de materiais biológicos como algas marinhas, fungos e bactérias vem se destacando e se tornando uma solução atrativa quando comparados com os tratamentos químicos convencionais; essa técnica é denominada biossorção. A biossorção é um processo de captação de íons metálicos de uma solução, a partir de interações entre o metal e determinados sítios ativos presentes na parede celular da biomassa. Existe também um crescente interesse pelo estudo dos elementos de terras raras (TR) por possuirem alto valor agregado, acarretado por processos caros e de alta complexidade na sua separação e purificação. Desta forma, este trabalho teve como objetivo descrever o potencial de biossorção de lantânio - um representante dos TR - pela macroalga Sargassum sp., a partir de soluções aquosas. Para isso foram realizados estudos em batelada, aplicando modelos cinéticos e de equilíbrio, e estudos em regime contínuo de biossorção dos íons de lantânio (III), além de um sistema contínuo bimetálico, no qual houve a adição do metal cério, outro TR. As determinações analíticas foram realizadas por espectrometria de emissão ótica por plasma indutivamente acoplado. Os ensaios cinéticos foram realizados nas concentrações metálicas de 10 e 100 mg.L-1 e em duas concentrações distintas de biomassa 2 e 5 g.L-1 na temperatura de 301C. Dois modelos cinéticos foram testados, pseudo-primeira ordem e segunda ordem, tendo o modelo de segunda ordem apresentado melhor ajuste dos dados, com r2 igual a 0,9697. No ensaio de equilíbrio foi construída a isoterma que apresentou um perfil crescente na captação no entanto não alcançou a remoção máxima. Os modelos de Langmuir e Freundlich foram utilizados para ajustar os dados da isoterma, sendo verificado maior correlação dos dados com o modelo de Langmuir; resultando num valor de captação máxima calculado pelo modelo de 3,55 mmol.g-1. No ensaio dinâmico foram realizados dois experimentos, 1 e 2. O Experimento 1 foi realizado com três colunas interligadas e recheadas com 20g de biomassa cada, sendo bombeada uma solução aquosa de lantânio na concentração de 1,41mmol.L-1. O Experimento 2 foi constituido de uma solução contendo lantânio e cério ambos na mesma concentração anterior de 1,41 mmol.L-1, sendo bombeada somente para uma única coluna recheada com 20g de biomassa. Os resultados demonstraram que o ponto de saturação não foi atingido dentro das 8 horas em que se deu o processo, o que indica a alta afinidade da Sargassum sp. pelo lantânio e que a presença do cério associada a redução da vazão prejudicou a captação do lantânio / Considering the utmost technological advances, researchers have intensified the searching for a new methodology on removing metals from wastewaters that can provide adequate outcomes as far as the metal uptake is concerned, allied with cost effectiveness of the process. The use of organic materials such as algae, fungi and bacteria has been highlighting and is becoming to be considered an interesting solution when compared to conventional chemical treatments. This technique is called biosorption, which is a process that captures metal ions from a solution, based on the interactions between metals and active groups present on the cell wall of the biomass. The interest on the application of this technique is growing and studies about the maximum concentration that can be discharged in the environment without harmful consequences and for the separation and recovery of rare-earth (RE) elements are being done. In this work, it was used the biomass Sargassum sp. as biosorbent in Lanthanum biosorption process. It was performed kinetic, equilibrium and continuous studies of biosorption of lanthanum ions (III) by means of a bimetallic continuous system, to which there was the addition of Cerium metal, another element of the RE. Analytical determinations were performed by inductively coupled plasma optical emission spectrometry. Kinetic experiments were performed at constant temperature of 30 1 C, metal concentrations of 10 and 100 mg.L-1 and at two different concentrations of biomass 2 and 5 g.L-1. Two kinetic models were tested, pseudo-first order and second order, and a comparison of the best fit was made from the second-order model with r2 equal to 0.9697. In the equilibrium experiment the isotherm was obtained with a rising profile in the capture, without reaching the maximum removal. The Langmuir and Freundlich models were used to help to fit the data of the isotherm, being the Langmuir model the one presenting greater correlation, with a maximum uptake value of 3.55 mmol.g-1. In the dynamic test, two experiments were conducted. Test 1 was conducted with three interconnected columns filled with 20g of biomass each, pumped the Lanthanum solution. Test 2 was made from Lanthanum solution and Cerium pumped for column with 20g of biomass. The results showed that the saturation point was not achieved in the 8h of the experiment, which indicates the high affinity of Sargassum sp by Lanthanum and that the presence of Cerium as well as flow reduction impaired the uptake of Lanthanum

Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / Adaptada dos conceitos da produção enxuta, a construção enxuta é uma filosofia de gestão da produção voltada à construção civil. Dos cinco princípios enxutos em que se baseia, o que mais tem se estudado desde a publicação do Relatório Técnico n72 Aplicação da Nova Filosofia de Produção à Construção (publicado pelo CIFE Center for Integrated Facility Engineering, ligado à Universidade de Stanford, EUA) é o Fluxo Contínuo. A idéia de manter o fluxo contínuo está diretamente ligada à continuidade da produtividade, ou seja, manter a produtividade em uma taxa constante. Aplicar o conceito enxuto de fluxo contínuo através da manutenção das taxas de produtividade significa gerenciar o empreendimento de modo que a execução das atividades se mantenha de acordo com os parâmetros estabelecidos durante a fase de planejamento. Por meio de ferramentas enxutas de gerenciamento é feita a simulação em Excel de três atividades pertencentes ao processo de execução de lajes prediais de edifícios construídos em estruturas metálicas: steel deck, armação e concretagem. A elaboração da planilha possibilita a avaliação das perdas ocorridas durante a execução das atividades sob a ótica do conceito de atrasos e esperas. A soma destas perdas resulta ainda em dois efeitos distintos considerados como perdas acumuladas e perdas compensadas, proporcionando ao gerente do empreendimento dados consistentes para traçar estratégicas para eliminação do desperdício ou uma antevisão dos desperdícios que podem estar associados à execução das atividades se estas forem mal planejadas. / Adapted from the concepts of lean production, lean construction is a management philosophy of the production directed to construction. Of the five lean principles what else has been studied since the publication of Technical Report No. 72 - Application of New Production Philosophy to Construction (published by CIFE - Center for Integrated Facility Engineering, connected to Stanford University, USA) is the continuous flow. The idea of maintaining the continuous flow is directly linked to continued productivity, ie keep productivity at a constant rate. Apply the concept of lean stream by maintaining productivity rates means managing the project so that the execution of activities is maintained in accordance with the guidelines established during the planning phase. Through lean management tools is done in Excel simulation of three activities from the implementation process of building slabs of buildings constructed in steel structures, steel deck, frame and concrete. The elaboration of the sheet allows the evaluation of the losses occurred during the execution of activities from the perspective of the concept of delays and waits. The total of these losses still result in two distinct effects considered to accumulated losses and offset losses, providing the manager of the project consistent data to plot strategy for disposal of waste or a preview of wastes that may be associated with the implementation of the activities if they are badly planned.

Orientador: Pilar Rodriguez de Massaguer / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T12:11:20Z (GMT). No. of bitstreams: 1 RodriguesJunior_Salatir_D.pdf: 5567332 bytes, checksum: 70d0366fec71ac0d7df65013c7939248 (MD5) Previous issue date: 2008 / Resumo: O presente trabalho teve por objetivo verificar o efeito da tensão de cisalhamento sobre os parâmetros cinéticos de inativação térmica (valores D e z) de Bacillus atrophaeus (antigo B. subtilis ATCC 9372), em suspensão aquosa pH 6,87. A fim de atingir esse objetivo, foi construído um reator de cisalhamento, capaz de aplicar tensões de cisalhamento de até 9,82Pa em temperaturas de pasteurização (90,5 a 96,2ºC ± 0,5ºC). Foi aplicado um Delineamento Composto Central Rotacional, com duas variáveis independentes ¿ Tensão de cisalhamento e Temperatura ¿ e valor D como variável resposta. Foram executados 12 experimentos, e o modelo obtido foi ¿Log (D) = 11,30 ¿ 1,104x10-1 T(ºC) ¿ 1,153x10-2 s(Pa)¿, com R² = 0,97, sendo os termos lineares das variáveis significativos a p < 0,1. Também foram determinados os valores D e z de B. atrophaeus na faixa de temperatura de pasteurização (92~97ºC), pelo método tradicional em tubos TDT (batelada), e usando dados cinéticos adquiridos de uma planta piloto HTST Microthermics (contínuo), em condições de tensão de cisalhamento similares àquelas aplicadas no reator. A fim de avaliar o processamento térmico contínuo aplicado na unidade HTST, foi usada a metodologia de determinação de processo equivalente conhecida como Paired Equivalent Isothermal Exposures ¿ PEIE (Welt et al., 1997). Os valores de z obtidos foram: 11,8ºC ± 1,56ºC pelo método TDT e 6,35ºC ± 0,35ºC no reator de cisalhamento e na primeira seção de retenção da unidade piloto HTST. Diversos autores reportaram mudanças nos parâmetros cinéticos de microrganismos, ao realizar a sua determinação por métodos em batelada (tubos TDT, ou capilar) e em processos contínuos. À semelhança desses autores, foi verificado que os valores D de B. subtilis foram significativamente (p<0.05) inferiores em todos os processos em que foi aplicado cisalhamento. A razão entre os valores D experimentais obtidos no reator de cisalhamento e os valores obtidos pelo modelo estimado pelo método TDT foi calculada, e variou entre 57% e 75%, indicando redução significativa na resistência térmica do microrganismo. Existe, portanto, potencial de aplicação industrial imediata deste tipo de sistema, a fim de causar a redução da resistência de esporos suspensos em líquidos sob processamento térmico, e levando a processos térmicos mais brandos / Abstract: This research aimed to determine the effect of temperature, and shear stress, on Bacillus atrophaeus (former B. subtilis ATCC 9372) spores suspended in sterile distilled water, pH 6.9. To achieve such objective, a Shear Reactor was developed to be capable of applying 9.82Pa shear stress, under pasteurization conditions (90,5 a 96,2ºC ± 0,5ºC). A Central Composite Design of experiments was used and it was composed by two independent variables ¿ Shear stress and Temperature ¿ and one response ¿ the D-value. Twelve experiments were performed, and the model obtained was ¿Log (D) = 11,30 ¿ 1,104x10-1 T(ºC) ¿ 1,153x10-2 s(Pa)¿, with R² = 0,97, and the linear terms statistically significant (p < 0,1). The D and z-values of B. atrophaeus were determined in the pasteurization range of temperature (92~97ºC), using the classical TDT tube method (batch method), and using kinetic data acquired in a Microthermics HTST pilot plant (continuous method), under shear stress conditions similar to shear reactor. The continuous thermal process was evaluated through the Paired Equivalent Isothermal Exposures ¿ PEIE ¿ method (Welt et al., 1997). The z-values obtained were: 11,8 ± 1,56ºC (TDT-method), and 6,35 ± 0,35ºC (Shear reactor and first retention section of the HTST pilot plant). Several authors reported changes in the kinetic parameters of microorganisms, when determining it through batch or continuous methods. Just like them, in this research it was verified that the D-values under shear stress process were statistically lower (p<0.05) than those in batch method (no shear). The ratio between experimental D values obtained in the shear reactor and those obtained from the TDT model was calculated and ranged between 57% and 75%, indicating a significant reduction of the microorganism¿s thermal resistance. Hence there is an immediate potential for industrial application of this kind of process since it causes the reduction of the resistance of spores in fluids under thermal process allowing for less aggressive thermal process / Doutorado / Doutor em Ciência de Alimentos