abstract: Synechocystis sp PCC 6803 is a photosynthetic cyanobacterium that can be easily transformed to produce molecules of interest; this has increased Synechocystis’ popularity as a clean energy platform. Synechocystis has been shown to produce and excrete molecules such as fatty acids, isoprene, etc. after appropriate genetic modification. Challenges faced for large–scale growth of modified Synechocystis include abiotic stress, microbial contamination and high processing costs of product and cell material. Research reported in this dissertation contributes to solutions to these challenges. First, abiotic stress was addressed by overexpression of the heat shock protein ClpB1. In contrast to the wild type, the ClpB1 overexpression mutant (Slr1641+) tolerated rapid temperature changes, but no difference was found between the strains when temperature shifts were slower. Combination of ClpB1 overexpression with DnaK2 overexpression (Slr1641+/Sll0170+) further increased thermotolerance. Next, we used a Synechocystis strain that carries an introduced isoprene synthase gene (IspS+) and that therefore produces isoprene. We attempted to increase isoprene yields by overexpression of key enzymes in the methyl erythritol phosphate (MEP) pathway that leads to synthesis of the isoprene precursor. Isoprene production was not increased greatly by MEP pathway induction, likely because of limitations in the affinity of the isoprene synthase for the substrate. Finally, two extraction principles, two–phase liquid extraction (e.g., with an organic and aqueous phase) and solid–liquid extraction (e.g., with a resin) were tested. Two–phase liquid extraction is suitable for separating isoprene but not fatty acids from the culture medium. Fatty acid removal required acidification or surfactant addition, which affected biocompatibility. Therefore, improvements of both the organism and product–harvesting methods can contribute to enhancing the potential of cyanobacteria as solar–powered biocatalysts for the production of petroleum substitutes. / Dissertation/Thesis / Ph.D. Plant Biology 2013

Ce doctorat a pour de comparer deux procédés d’extraction de biomolécules, comme l’acide gallique. Le phosphate de tributyle (TBP), dilué dans le dodécane, est choisi comme extractant et Na2HPO4 comme désextractant pour leur efficacité. Avec ces réactifs, nous avons déterminé le mécanisme des deux systèmes extractifs. L’extraction liquide-liquide est limitée par l’équilibre thermodynamique : elle est efficace pour des concentrations élevées de TBP. Quant à l’extraction par émulsion, elle ne l’est pas ; si l’émulsion est stable, l’extraction peut être rapide et totale avec des concentrations de TBP plus faibles, ce qui rend ce procédé plus vert que le précédent. La dernière partie de l’étude porte sur le remplacement du dodécane par des agrodiluants afin d’obtenir des procédés encore plus verts. L’utilisation d’esters éthyliques d’acide gras permet d’augmenter l’extraction en présence de TBP et même d’éviter son emploi en extraction par émulsion. / This aim of this study was to compare liquid-liquid extraction (LLE) and extraction by emulsion (ELM) of biomolecules as gallic acid. TBP as the extractant and Na2HPO4 as the stripping agent were chosen thanks to their efficiency. The influence of many parameters on these two processes was studied to determine their mechanism. LLE process is limited by equilibrium: the extraction is efficient for high TBP concentrations (> 20 % v/v). This is not the case for ELM process: if the emulsion was stable, the extraction was quantitative within a few minutes with lower extractant concentrations, which made ELM process more environment-friendly. By using agrodiluents to replace dodecane for more environmental-friendly processes, interesting results were obtained. In ELL, higher extraction yields were obtained with TBP diluted in ethylic esters of fatty acids. Even, in ELM, gallic acid was quantitatively extracted without TBP.

Orientador: Elias Basile Tambourgi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-06T11:03:14Z (GMT). No. of bitstreams: 1 Cesar_AnaClaudiaWabiszczewicz_D.pdf: 433934 bytes, checksum: b603e81d6b5be21cf414417fb7c4a679 (MD5) Previous issue date: 2005 / Resumo: O Brasil encontra-se entre um dos maiores produtores mundiais de abacaxi ocupando o terceiro lugar no ranking mundial. Visando o aproveitamento do material considerado resíduo agrícola (caule e folhas) e resíduos do processamento do fruto, muitos estudos tem sido realizados para a obtenção de enzimas proteolíticas do abacaxi. As enzimas proteolíticas de origem vegetal são provenientes principalmente do figo (ficina), do mamão (papaína) e do abacaxi (bromelina). Por bromelina entende-se o conjunto de enzimas proteolíticas produzidas por plantas da família das Bromeliaceae. É uma enzima de amplo uso na indústria alimentícia para o amaciamento de carne e clarificação da cerveja, para o amaciamento de couro, e na indústria farmacêutica, em medicamentos destinados a distúrbios de digestibilidade,e também por sua ação antiinflamatória e antimucolítica. O desenvolvimento de novos processos de extração e purificação de proteínas é muito importante, uma vez que esta é uma etapa limitante na produção de bioprodutos. O presente trabalho propõe um processo de recuperação da bromelina do fruto de abacaxi por técnica de precipitação do caldo prensado com etanol frio onde foram obtidos resultados demonstrando que em uma precipitação em 1 estágio com 80% v/v de etanol a 5°C é possível recuperar praticamente toda a enzima originalmente presente, aumentando de 3 a 5 vezes a atividade específica inicial e purificação através da extração líquido-líquido em duas fases aquosas, formado por duas fases aquosas imiscíveis ou parcialmente miscíveis entre si , obtidas pela adição de polímeros hidrofílicos ou um desses polímeros e um sal , como o sistema PEG ( polietileno glicol ) e o fosfato de potássio. O trabalho apresenta um estudo sobre os custos do processo e estimativas sobre o preço de venda e retorno sobre o investimento , demonstrando a viabilidade econômica da proposta quer para utilização como pré-processo nos tradicionais sistemas cromatográficos, quer para sua comercialização direta, como alternativa para o produtor do abacaxi, ou do fabricante de sucos e compotas / Abstract: Brazil is one of the world¿s largest producers of pineapples, its production being the third one in the world. To take advantage of the residues from fruit processing, many studies have been conducted to obtain proteolytic enzymes from them. These proteolytic enzymes are extracted mainly from fig (ficine), papaya (papain), and pineapple (bromelain). Bromelain is a mixture of proteolytic enzymes found in Bromeliaceae family. It is an enzyme with ample use in food industry for meat tenderizer and beer clarification, in leather and pharmaceutical industries, in drugs for digestion disorders, anti-inflammatory action, and anti-colitis action. The development of new extraction and purification processes of proteins is very important, as this is a limiting step in the production of byoproducts. The present work proposes a recovery process of bromelain from pineapples by precipitation of their pressed juice with cold ethanol, whereby a one stage precipitation with 80% v/v of ethanol at 5°C made possible the recovery of practically all originally present enzyme, increasing from 3 to 5 times the initial specific activity and purification by a liquid-liquid extraction in two aqueous phases, formed by immiscible aqueous phases or partially miscible ones, which are obtained from the addition of hydrophilic polymers or one of these polymers and a salt, such as PEG system (polyethylene-glycol) and potassium phosphate. This work presents a study about the costs of this process and the estimated sale prices as well as its return of investment, showing its economic viability, whether it is for use as a pre-process in traditional chromatographic systems or direct commercialisation, as an alternative for the pineapple producer of the juice market / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Orientador: Antonio Jose de Almeida Meirelles, Christianne Elisabete da Costa Rodrigues / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T12:11:40Z (GMT). No. of bitstreams: 1 Sa_LeticiaAndradede_M.pdf: 1111674 bytes, checksum: 4740d77e5f31018175a3214d8d9ef4da (MD5) Previous issue date: 2007 / Resumo: O processo de desacidificação do óleo de soja por extração líquido-líquido (ELL) foi estudado em uma coluna de discos rotativos perfurados (PRDC), operada de modo contínuo e contra-corrente. Foram estudados sistemas-modelo formados por óleo de soja refinado com adição artificial de aproximadamente 2% de ácido linoléico comercial. Até o momento, os estudos de desacidificação de óleos vegetais por ELL realizados no Laboratório de Extração, Termodinâmica Aplicada e Equilíbrio (ExTrAE) haviam sido feitos com óleos que apresentavam teores mais altos de acidez (3 a 8%). O diferencial deste trabalho está no fato de o óleo de soja bruto apresentar baixa acidez (cerca de 2%). Outro diferencial foi a utilização de temperatura superior (50 °C) à ambiente e teor mais elevado de água no solvente, permitindo diminuir a perda de óleo neutro sem uma diminuição significativa da capacidade de o solvente extrair os ácidos graxos livres. Os experimentos foram analisados por metodologia de superfície de resposta, que permitiu avaliar a influência do teor de água no etanol (0 a 12% em massa) e da velocidade de rotação dos discos (50 a 150 rpm) na transferência de acidez e na perda de óleo neutro. Os resultados experimentais mostraram que é possível obter um óleo refinado com teor de acidez abaixo do exigido pela legislação (< 0,3%) quando se utiliza etanol anidro. Entretanto, para se atingir este objetivo utilizando altos teores de água no solvente, deve-se aumentar a altura da região de extração da coluna para transferir maior quantidade de ácidos graxos livres e para que a perda de óleo neutro seja no máximo 3%, inferior ao valor das perdas relatadas na literatura para o refino químico / Abstract: The deacidification process of soybean oil by continuous liquid-liquid extraction (LLE) was evaluated in a perforated rotating discs contactor column (PRDC). It were studied model-systems formed by refined soybean oil with artificial addition of approximately 2% of commercial linoleic acid. Until the moment, the studies of vegetable oils deacidification by LLE accomplished in the Laboratory of Extraction, Applied Thermodynamic and Equilibrium (ExTrAE) had been carried out with oils that presented higher acidity (3 to 8%). The differential of this work is in the fact that the crude soybean oil has low acidity level. Another differential was the use of a temperature (50 °C) higher than the environment and higher water contents in the solvent, allowing to reduce the loss of neutral oil without a significant reduction of the capacity of the solvent to extract the free fatty acids. The experiments were analyzed by response surface methodology, that allowed to evaluate the influence of the water in the ethanol (0 to 12% in mass) and the rotating speed of the discs (50 to 150 rpm) in the acidity transfer and on the loss of neutral oil. The experimental results showed that it is possible to obtain a refined oil with low acidity, below the required by legislation (< 0.3%) when anhydrous ethanol is used. However to reach this objective using high contents of water in the solvent, the height of the extraction region of the column must be increased to transfer greater to amount of free fatty acids and so that the loss of neutral oil is low (maximum 3%), less than the value of losses related in literature for the chemical refining / Mestrado / Mestre em Engenharia de Alimentos

Orientador: Elias Basile Tambourgi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T00:12:34Z (GMT). No. of bitstreams: 1 Elias_MoacyrJorge_D.pdf: 3281919 bytes, checksum: a06d734eab8439e1da9e683c7b3eb667 (MD5) Previous issue date: 2010 / Resumo: A bromelina, enzima presente no abacaxi, hidrolisa ligações peptídicas das proteínas; tem aplicação em diversas áreas envolvendo alimentos, medicina e nutrição animal. No abacaxi a bromelina está presente no talo, na polpa e na casca do fruto. Visando avaliar a bromelina presente no fruto brasileiro Ananás comosus L. Merril, variedade pérola, enfocando seu aproveitamento quando recuperada a partir dos resíduos da industrialização, foram pesquisadas, em comparação com a bromelina pura, condições de pH e temperatura para maior atividade, estabilidade térmica ao longo do tempo em várias temperaturas e a cinética da sua atividade catalítica, empregando caseína como substrato. O extrato foi obtido pela trituração da casca e do talo interno do fruto e a reação de hidrólise, com pH controlado, efetuada em reator com 75 mL de volume útil sob constante agitação. Após a reação foi retirada amostra, adicionada em tubo contendo ácido tricloroacético e centrifugado, analisando a absorbância do sobrenadante. Atividade e a cinética foram expressas em mmol tirosina / L.minuto pela absorbância a 280 nm dos aminoácidos aromáticos gerados na hidrólise da caseína. Foram empregadas três relações enzima / substrato (em massa): 1 / 25, 1 / 50 e 1 / 125 para os ensaios relativos ao planejamento experimental em estrela tendo como ponto central pH em 7,0 e temperatura de 35 °C, os resultados foram tratados fornecendo as equações do modelo e as superfícies de resposta; as equações foram tratadas matematicamente fornecendo gráficos da melhor atividade em função da temperatura; os resultados do planejamento experimental mostraram similaridade entre a bromelina dos resíduos do fruto e a bromelina pura tomada como padrão. Para a estabilidade térmica os ensaios foram efetuados determinando a atividade para a relação 1 / 25 sob temperaturas variando entre 25 °C e 62 °C ao longo de 180 minutos com duas faixas de pH: a de melhor atividade definida no planejamento experimental (5,5 a 6,5) e entre 3,3 e 3,5; os resultados foram tratados analisando o gráfico da atividade em função do tempo mostrando que o modelo de ordem um é adequado para descrever a inativação térmica da enzima e que ela ocorre de maneira mais acentuada na faixa de pH 3,3 a 3,5 com valor do fator de freqüência k0 (minuto-1) 2,5 x1032 vezes maior para o extrato. Os ensaios para determinar a cinética da atividade catalítica da bromelina sobre a caseína foram efetuados a temperatura constante de 35 °C e pH de máxima atividade definido no planejamento experimental para cada uma das três relações enzima / substrato estudadas; foram elaboradas as curvas da concentração de aminoácidos formados ao longo do tempo (zero a 15 minutos) e os resultados tratados calculando a derivada das curvas no tempo zero (velocidade inicial); o modelo de Michaelis - Menten mostrou ser adequado para descrever o mecanismo de hidrólise da caseína pela bromelina e os resultados indicam que os valores da velocidade máxima (Vmax) e da constante de Michaelis (Km) são maiores para o extrato dos resíduos do fruto do que para a bromelina pura. / Abstract: The bromelain, enzyme found in pineapple, hydrolyses peptide protein bonds; there is application in several areas involving food, medicine and animal nutrition. In pineapple the bromelain is present in the flesh, skin and core of the fruit. Aiming to evaluate the bromelain present in Brazilian fruit Ananas comosus L. Merril, pérola type, focusing its use from industrialization residues recovering, it was searched, comparing with pure bromelain, pH conditions and temperature for higher activity, thermal stability along the time under several temperatures and the kinetics of its catalytic activity, using casein as a substrate. The extract was obtained crushing the skin and core of the fruit and the hydrolysis reaction, with controlled pH, done in a 75 mL net volume reactor under constant stirring. After reaction a sample was taken, added to a tube with tri chloroacetic acid and centrifuged, analyzing the supernatant absorbance. Activity and kinetics were expressed as mmol of tyrosine / L.min from absorbance at 280 nm of aromatic amino acids generated by casein hydrolysis. Three enzyme / substrate ratio were employed (weight basis):1 / 25, 1 / 50 and 1 / 125 for star type experimental design assays with central point at 7.0 for pH and at 35 °C for temperature, the results were processed giving the model equation and surface responses, the equations were mathematically treated giving graphics of best activity as a function of temperature; the experimental design results showed similarity between bromelain from fruit residues and pure bromelain taken as reference. The assays for thermal stability were carried out by activity determination for 1 / 25 ratio under temperatures varying from 25 °C and 62 °C during 180 minutes for two pH ranges: that for best activity defined from experimental design (5.5 to 6.5) and between 3.3 to 3.5; the results were treated by the analysis of the graphics of activity as a function of time showing that the order one model is adequate to describe the enzyme thermal inactivation and that it is stronger at pH range of 3.3 to 3.5 with values of frequency factor k0 (minute-1) 2.5 x1032 times bigger for the extract.The assays to determine the kinetics of bromelain catalytic activity on casein were carried out at constant temperature of 35 °C and pH of maximum activity defined by experimental design for each one of the three studied enzyme / substrate ratio; curves were built for the concentration of formed amino acids along the time (from zero to 15 minutes) and the results treated calculating the curves derivative at time zero (initial rate); the Michaelis - Menten model showed to be adequate to describe the casein hydrolysis mechanism of casein by bromelain and the results indicate that the maximum reaction rate (Vmax) values and the Michaelis constant (Km) values are bigger for the fruit residues extract than that for pure bromelain. / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Orientador: Elias Basile Tambourgi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T00:05:27Z (GMT). No. of bitstreams: 1 Barros_KleberVanioGomes_M.pdf: 726082 bytes, checksum: f7ee21d9c4e2a18b7c38d3e3a1baccd2 (MD5) Previous issue date: 2009 / Resumo: O curauá (Ananas erectifolius) é uma planta fibrosa proveniente da Amazônia brasileira, pertencente à família Bromeliaceae e ao gênero Ananas. A bromelina é uma protease de origem vegetal, obtida de diversas espécies da família Bromeliaceae. A bromelina tem utilização bastante difundida em processos industriais nas áreas alimentícia e farmacêutica. Efeitos antiinflamatórios da enzima, como também, o seu uso no tratamento da angina, na indigestão entre outros, estão documentados na literatura científica. Estudos de métodos para purificação de biomoléculas que viabilizem a sua obtenção em larga escala com custo reduzido são importantes áreas de pesquisa na biotecnologia. A extração líquido-líquido através de sistemas bifásicos aquosos (SBA) pode ser usada como técnica de pré-purificação de bioprodutos. Estes sistemas formam duas fases aquosas imiscíveis ou parcialmente miscíveis entre si. Podem ser formados a partir da mistura de dois polímeros ou de um polímero e um sal, a exemplo do sistema PEG (polietilenoglicol)/fosfato de potássio. Foi estudada a enzima bromelina derivada das folhas de ambas as variedades: curauá branco e curauá roxo. Pesquisou-se também a recuperação da enzima por extração líquido-líquido em sistemas de duas fases aquosas PEG/fosfato. Realizou-se ensaios em batelada para a extração e recuperação da enzima, utilizando como indicador o coeficiente de partição. Obteve-se fatores de purificação da enzima bromelina para o sistema fosfato de potássio e polietileno glicol 4000 e 6000, nos pH de 7,0; 8,0 e 9,0 a 25 °C. Estudou-se a partição em três diferentes "tie-lines". Analisou-se a influência do pH e do comprimento das linhas de amarração no coeficiente de partição da enzima. Na purificação da bromelina derivada das folhas do curauá branco, observou-se os melhores resultados no sistema bifásico aquoso PEG 4000/Fosfato em pH 7,0. Observou-se que o sistema PEG 6000/Fosfato em pH 7,0 apresentou os melhores resultados em relação à purificação da enzima bromelina derivada das folhas do curauá roxo. / Abstract: The curauá (Ananas erectifolius) is a fibrous plant from brazilian Amazon, belonging to the Bromeliaceae family and Ananas genus. Bromelain is a protease from vegetable origin, obtained from several species of this family. The bromelain has widespread use in industries process, such as in food and pharmaceutical areas. Antiinflammatory effects enzyme and also it uses in angina treatment, indigestion among others are documented in scientific literature. Methods' studies to purification of biomolecules that allow their achievement in large scale with low cost are important research's areas in biotechnology. The liquid-liquid extraction through aqueous twophase system (ATPS) can be used as technical of pre-purification of bioproduct. These systems form aqueous two-phase immiscible or partially miscible within themselves. They can be obtained by the addition of two polymers or one polymer and a salt, such as the PEG - poly(ethyleneglycol) - and potassium phosphate salt system. In the present report we characterized the bromelain enzyme that comes from the leaves of white curauá and purple curauá, and also investigated the recuperation of the enzyme by liquid-liquid extraction in aqueous two-phases PEG-phosphate systems (ATPS). The assays to extraction and recovery of the enzyme were carried out in batch mode, using the partition coefficient as indicator. Getting to factors purification of the enzyme bromelin to PEG 4000 and 6000 and potassium phosphate salt in ATPS, at pH 7.0, 8.0 and 9.0 at 25 ºC. We studied the partition through three different tie-lines. The influences of pH and tie-line length in partition coefficient of enzyme were analyzed. In the purification of bromelain derived from the leaves of white curauá, we observed the best results in PEG 4000/phosphate ATPS at pH 7.0. Furthermore, the system PEG 6000/phosphate at pH 7.0 showed the best results in relation to the purification of the enzyme bromelain derived from the leaves of purple curauá. / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Fresh water in Kuwait is produced by non- conventional methods. About 95% of this water comes from desalinated seawater using multi-stage flash distillation technique and the remainder comes from underground brackish water. The blended water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and zinc have been analysed using atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectroscopy (ICPMS). Efforts were made to improve the preconcentration of the selected metals and their separation from the high concentration of salts in seawater which affect the accuracy and cause major interference in the analysis. Solid-liquid extraction (chelex-100 resin) and liquid-liquid extraction (methyl iso-butyl ketone and freon) with and without back-extraction into nitric acid were investigated. Liquid-liquid extraction without back-extraction proved to give optimum recovery of the selected metals. Results confirmed that both AAS and ICP-MS are suitable for the analysis of trace metals in Kuwait's waters. Although AAS technique proved to be more accurate in analysing the selected metals than ICP-MS, the latter was adopted since its accuracy is acceptable (1.1-4.4%) and it is easier and faster than the former technique. The study revealed that the source of copper, iron, nickel and zinc is the construction materials of the distillation plants, while the source of lead and vanadium is the brackish water. Manganese and chromium concentrations are very low in all sources. No direct relationship between the metal concentration in the seawater and the distillate could be deduced.

Countercurrent chromatography (CCC) is an advanced liquid-liquid extraction technique that purifies chemical components from complex mixtures. The Brunel CCC' is a J-type centrifuge based upon this technique. This machine can process 5g quantities of sample every 5 hours [Sutherland 1998]. To process 1 tonne of sample per year would require 200 Brunel CCCs, which is not practical as an industrial process. A practical alternative is to use one machine with 200 times the processing capability. To construct such a machine requires a greater understanding of the stationary phase retention inside a coil (column) and the column efficiency (mass transfer between the mobile and stationary phases). This thesis contains research into stationary phase retention. A hypothesis that all J-type centrifuges act as constant pressure drop pumps is proposed. This hypothesis combined with the Hagan-Poiseuille equation for laminar flow produces a theoretical basis for plotting the stationary phase retention against the square root of the mobile phase flow rate as proposed by Du et al [1999]. Supporting experimental evidence is presented showing that the mobile phase flows in a laminar manner and that the pressure drop across a coil is constant for a given set of operating conditions. It is shown that the pressure drop is the same in both normal and reverse phase modes if specific conditions are met. The pressure drop is shown to be independent of tubing bore for helical coils provided that the same helical pitch is used. The experimental results also show how the pressure drop varies with the phase system and rotational speed. Hopefully this is a significant advance in predicting the stationary phase retention of industrial scale J-type centrifuges.

Cette thèse avait pour objectif de développer de nouveaux systèmes d’extraction liquide-liquide compatibles avec le procédé Prayon pour la purification de l’acide phosphorique produit par voie humide. Une étude bibliographique complète des solvants d’extraction étudiés dans la littérature pour l’extraction liquide-liquide de l’acide phosphorique nous a permis d’identifier des candidats potentiellement intéressants. Une étude approfondie des propriétés d’extraction de ces systèmes et de leur sélectivité vis-à-vis des espèces métalliques nous a finalement permis de nous focaliser par la suite sur trois solvants d’extraction : le dibutyl éther (DBE), le diisobutyl carbinol (DiBC) dilué dans le diisopropyl éther (DiPE) et la Fentamine T0810 (ATS) dilué dans le DiPE. La formulation de ces mélanges a ensuite été optimisée en veillant à étudier le comportement de ces systèmes à chaque étape du procédé d’extraction liquide-liquide, c’est à dire l’extraction, la désextraction et le lavage. Cette étude a également permis de fixer les conditions opératoires optimales, notamment le rapport des volumes des phases. Au cours de cette étude, des phénomènes complexes de transitions de phases réversibles de la phase organique de monophasique vers biphasique (formation de troisième phase) et biphasique vers monophasique (retour à une phase organique unique) ont été mis en évidences expérimentalement. Pour finir, un modèle physicochimique d’extraction fondé sur des bilans de masse a été développé. Ce modèle s’avère très utile pour décrire l’extraction de l’acide phosphorique et de l’eau et la variation des volumes des phases au cours de l’extraction. / This PhD thesis was focused on the development of new extraction systems to purify phosphoric acid from wet phosphoric acid (WPA). The new system should be respectful of the current Prayon’s process flowsheet designed for the use of the mixture tri-n-butyl phosphate(TBP) and diisopropyl ether (DiPE) as extraction solvent. Firstly, extractants exhibiting different structures and functional groups were screened in order to assess their efficiency and selectivity towards phosphoric acid. Three new promising extraction systems were identified: diisobutyl ether (DBE), diisocarbinol (DiBC) in DiPE, and Fentamine T0810 (ATS) in DiPE. Secondly, our effort was directed to the comprehension of the physico-chemical phenomena involved in the extraction of phosphoric acid by the mixture TBP/DiPE at first, and enriched to describe the other systems studied later. Finally, a simulation model describing the solvent extraction of phosphoric acid by the solvent currently employed by Prayon is presented. This model accounts for the significant volume variation during the extraction of phosphoric acid and allows performing optimizations of extraction parameters even at very high phosphoric acid concentrations (6-14M).

Orientador: Roberta Ceriani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-27T08:35:18Z (GMT). No. of bitstreams: 1 Homrich_PerciOdilonBonetti_M.pdf: 5015007 bytes, checksum: f5fb89127af3308329cf79ba684bb5c2 (MD5) Previous issue date: 2015 / Resumo: O girassol é a oleaginosa que se apresenta em quarto lugar em relação à produtividade agrícola destinada à obtenção de óleos e possui vantagens por apresentar uma grande quantidade de ácido linoléico (ácido graxo polinsaturado) e compostos nutracêuticos, trazendo benefícios à saúde humana. O óleo de semente de girassol deve passar pelo processo de refino químico para remover a acidez e compostos minoritários para que se torne comestível. O processo de refino químico consiste, basicamente, de quatro etapas: degomagem, desacidificação, branqueamento e desodorização. A etapa de desodorização remove compostos odoríferos (principalmente aldeídos) formados pela oxidação do óleo, além de contaminantes, como pesticidas, por esgotamento com vapor de arraste sob altas temperaturas (até 265 °C) e alto vácuo. Essas condições drásticas de processamento causam a degradação e a volatilização de compostos nutracêuticos (principalmente antioxidantes), além de reações de oxidação e isomerização cis-trans de ácidos graxos insaturados. Neste contexto, este trabalho investigou a possibilidade de pré-tratar o óleo de girassol com solvente, removendo os odores do óleo bruto por extração líquido-líquido, o que possibilitaria uma posterior etapa de desodorização com condições operacionais mais brandas. Para isso, os dados de equilíbrio líquido-líquido para sistemas modelos compostos por óleo de semente de girassol + aldeídos + etanol anidro a 25 ºC foram experimentalmente determinados, sendo os sistemas quantificados por três métodos distintos. A partir dos dados obtidos, os parâmetros coeficiente de distribuição e seletividade do solvente indicaram que a extração dos aldeídos com solvente foi satisfatória, e a correlação dos dados pelos modelos termodinâmicos NRTL e UNIQUAC indicou que o NRTL correlacionou de forma mais fidedigna os resultados, apresentando um desvio global que variou entre 0,4447 e 0,7203 % / Abstract: Sunflower seed oil is the oilseed that represents the fourth major agricultural productivity destined to obtaining refined oils, possessing some advantages due to its high quantity of linoleic acid (polyunsaturated fatty acid) and nutraceutical compounds, promoting benefits to human health. In order to become edible, sunflower oil must be chemically refined for removing free fatty acids and minority compounds. Basically, chemical refining consists of four steps: degumming, deacidification, bleaching and deodorization. The deodorization step removes odoriferous compounds (mainly aldehydes), formed by the oil oxidation reaction, in addition to contaminants, such as pesticides, by a steam stripping under high temperatures (up to 265 °C) and very low pressures. These drastic process conditions result in the degradation and volatilization of nutraceutical compounds (mainly antioxidants), and favor the occurrence of oxidation and cis-trans isomerization reactions of the unsaturated fatty acids. In this context, this work investigated the possibility to pre-treat the sunflower oil with a solvent, removing the crude oil odors by liquid-liquid extraction, which would enable a posterior deodorization stage with milder operational conditions. To achieve this purpose, the liquid-liquid equilibrium data for model systems composed by sunflower seed oil + aldehydes + anhydrous ethanol at 25 °C were experimentally determined and the systems were quantified using three different methods. From the experimental data obtained, the distribution coefficient and the solvent selectivity parameters indicated that aldehydes extraction using ethanol as solvent was satisfactory, and the data correlation done by the thermodynamics methods NRTL and UNIQUAC showed that the NRTL model faithfully correlated the experimental data, presenting a global deviation that varied between 0.4447 and 0.7203 % / Mestrado / Engenharia Química / Mestre em Engenharia Química