Due to the ever increasing need for sustainable development, the chemical and allied industries have been at the focus of much change. Decreasing tolerances on pollution via waste streams has resulted in a re-examination of many chemical processes. This has ushered in the era of 'green chemistry' which incorporates the synthesis of a process in both a sustainable and economically viable manner. In the petroleum and chemical industries, this has led to the search for alternatives to volatile organic compounds. Ionic liquids provide one such alternative. With a wide liquid phase and no measurable vapour pressure, ionic liquids have been found to be successful as a medium for reactions. Ionic liquids differ from high-temperature molten salts in that they have a significantly lower melting point. This work investigates the use of ionic liquids as solvents in separations. The work focuses on the separation of alpha-olefins from complex mixtures. The ionic liquids used in this study were: • l-methyl-3-octyl-imidazolium chloride • 4-methyl-N-butyl-pyridinium tetrafluoroborate • trihexyl-tetradecyl-phosphonium chloride Three experimental techniques used to evaluate ionic liquids were: • gas-liquid chromatography • liquid-liquid equilibria measurements • vapour-liquid equilibria measurements l-Methyl-3-octyl-imidazolium chloride ((MOIM)C1) was used as a stationary phase in gas-liquid chromatography. The solutes used were: • Alkanes: n-Pentane; n-Hexane; n-Heptane; n-Octane • Alkenes: 1-Hexene; 1-Heptene; l-Octene • Alkynes: l-Hexyne; l-Heptyne; 1-0ctyne • Cycloalkanes: Cyclopentane; Cyclohexane; Cycloheptane • Aromatics: Benzene; Toluene Activity coefficients at infinite dilution were measured at temperatures (298.15, 308.15 and 318.15) K. Values at 298.15 K ranged from 1.99 for benzene to 26.1 for n-octane. From the temperature dependence of the activity coefficients, the partial excess molar enthalpies at infinite dilution were calculated. These range from 2.0 kJ.mol'l for l-octyne to 7.3 kJ.mol·1 for n-pentane. (MOIM)C1 shows reasonable ability to separate 1-hexene from the longer n-alkanes and aromatics. 4-Methyl-N-butyl-pyridinium tetrafluoroborate (BuMePyBF) was used as a solvent in liquid-liquid equilibria measurements. The following systems were measured at 298.2 K: • LLE System 1: BuMePyBF4 + 1-Hexene + Toluene • LLE System 2: BuMePyBF4 + 1-Hexene + Ethanol • LLE System 3: BuMePyBF4 + 1-Hexene + 2-Butanone • LLE System 4: BuMePyBF4 + 1-0ctene + Ethanol LLE System 1 is a type 11 system and the other systems being type I. All systems exhibit a large two-phase region. LLE System 1 shows low distribution. LLE System 3 show almost equal distribution between phases resulting in a distribution ratio of close to 1. LLE Systems 2 and 4 show high distribution ratios at low concentrations of solute. LLE Systems 1 and 3 show low to moderate selectivity of the solvent towards the solute. LLE Systems 2 and 4 show high to moderate selectivity, but decrease exponentially with increasing solute concentration in the organic phase. For all systems investigated, the solvent shows no miscibility with feed solutions of low to medium solute concentration. The binodial curves were correlated to the Hlavaty equation, the beta function and the log gamma function. The correlations yielded acceptable results for LLE Systems 2, 3 and 4. The tie-lines were correlated to the NRTL model, with LLE systems 2 and 4 giving acceptable results and LLE systems 1 and 3 give excellent results. The following binary vapour-liquid equilibrium systems were measured: • Acetone + Methanol at 99,4 kPa • l-Hexene + 2-Butanone at 74.8 kPa The acetone + methanol system exhibits a minimum boiling azeotrope at 0.78 mole fraction acetone. The l-hexene + 2-butanone system exhibits a minimum boiling azeotrope at 0.83 mole fraction l-hexene. Trihexyl-tetradecyl-phosphonium chloride (CJ3C1PhCl was then added to the above systems in order to evaluate it as a solvent in extractive distillation. (CJ3C1PhCI shifts the azeotrope of the acetone + methanol system to a higher acetone concentration, but does not remove it altogether. (CJ3C1PhCI has a negative effect on the relative volatility of the l-hexene + 2-butanone, thus rendering it ineffective as an extractive distillation solvent for this system. Another aspect that was considered in this work was the production of an ionic liquid. Synthesis steps and experimental considerations were discussed. A major factor in the use of ionic liquids is the cost of the ionic liquid itself. The major problem associated with ionic liquids is the general lack of available information that is necessary for them to be implemented in a process. Ionic liquids show potential as solvents in liquid-liquid extraction for a number of systems. Their potential as solvents in extractive distillation is probably limited, due to their miscibility/immiscibility properties, to systems involving slightly polar to highly polar compounds. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.

Accurate and reliable vapour-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) data are the key to a successful design and simulation of most important industrial separation processes (traditional distillation, extractive and azeotropic distillation). This work focuses on measurement of new phase equilibrium data for systems comprising of propan-1-ol, water and diisopropyl ether which are of important use in the petrochemical industry. In addition, an investigation of phase equilibrium behavior for systems of interest constituted by solvents and high added-value oxygenated compounds deriving from lignocelluloses biomasses (bio-fuels) was conducted at the Ecole des Mines de Paris CEP/TEP laboratories (France).Various data bases such as Science Direct, ACS publications and Dortmund Data Bank (DDB, 2009) were used to confirm that no literature data is available for these systems. The VLE data measurements for the system of propan-1ol + water and propan-1ol + diisopropyl ether (DIPE) ( 333.15, 353.15 and 373.15 K ) were carried out using a dynamic still of Lilwanth (2011), with a test system (ethanol + cyclohexane at 40 kPa) undertaken prior measurements to confirm the accuracy of the method and apparatus.The phase equilibrium (VLE and LLE) behaviours for furan + n-hexane and furan + Methylbenzene, furfural + n-hexane and furan + water were determined at 101.3 kPa. The atmospheric dynamic ebulliometry was used to measure VLE systems at 101.3 kPa. A set of LLE data for furfural + n-hexane and furan + water systems were obtained using a static analytical method, with a newly commissioned LLE apparatus. Furfural + n-hexane system was compared used as test system, to verify the reliability of the new equipment. The NRTL model was used to correlate the LLE data, with Cox- Herington model used to predict the entire LLE curve for furfural+ n-hexane system. The experimental VLE data were correlated using the combined y − y method. The vapour phase non idealities were described using the methods from Nothnagel et al. (1973), Hayden and O’Connell (1975) and the Peng-Robinson (1976) model. The activity coefficients were correlated using the NRTL model of Renon and Prausnitz (1968) and the modified UNIQUAC model of Abrams and Prausnitz (1976). A propan-1-ol dehydration process was simulated using Aspen to illustrate the use and importance of thermodynamic models in industrial process design and simulation. The model used in the simulation was validated with measured VLE and literature LLE data. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

Neste trabalho aplicou-se a metodologia diferencial para o cálculo do equilíbrio osmótico dentro da abordagem de Lewis-Randall para sistemas multisolventes. Nessa abordagem, são obtidas equações diferenciais que relacionam pressão e composição do sistema na condição de potencial químico constante dos solventes: o estado de equilíbrio osmótico é calculado integrando-se as equações, obtendo-se a curva de pressão osmótica em função da concentração do soluto. Essas equações não têm solução analítica, mas foram numericamente integradas para sistemas cuja não idealidade seja descrita pelo modelo UNIQUAC. A metodologia foi aplicada na análise de sistemas em que ocorre equilíbrio de fases líquido-líquido, o que em princípio corresponde ao teste mais severo a que pode ser submetida. A comprovação da eficácia da metodologia foi feita por meio da verificação das relações de equilíbrio nos passos intermediários e pela equação de Gibbs-Duhem. Os resultados mostraram que a abordagem é bastante confiável, e que o equilíbrio é corretamente calculado para uma variedade de situações. Foi possível discernir os casos em que é admissível utilizar um pseudo-solvente na descrição do equilíbrio osmótico (sistemas cujos solventes apresentam estruturas semelhantes, sem interação preferencial), e situações em que o cálculo pode não levar a resultados adequados (sistemas em que os solventes apresentem miscibilidade parcial). Os programas desenvolvidos são genéricos e, portanto, podem ser usados para o cálculo do equilíbrio osmótico em qualquer sistema descrito pela equação UNIQUAC. / A differential approach to the calculation of osmotic equilibrium of multisolvent systems within the Lewis-Randall framework is presented in this work. Differential equations relating pressure and composition at constant solvent chemical potential are developed, through whose integration the osmotic equilibrium is calculated. The curves of osmotic pressure as functions of the solute concentration cannot be analytically calculated, and were obtained through numerical integration. The methodology was used to calculate osmotic equilibrium for systems described by the UNIQUAC equation presenting liquid-phase split, which presumably corresponds to the most severe test. The approach was verified by checking the equilibrium conditions at intermediate points and also by checking the Gibbs-Duhem equation. The results show that the methodology is reliable and that the osmotic equilibrium can be correctly calculated for many situations. It was possible to identify the circumstances wherein a pseudo-solvent can be defined (systems whose solvents show similar structures, without presenting preferential interactions), and wherein the calculation may lead to unreliable results (systems wherein the solvents present partial miscibility). The computer programs developed are not specific, and can therefore be used to calculate osmotic equilibrium for any systems described by the UNIQUAC equation.

A produção de compostos a partir de carboidratos conhecidos como blocos de construção tem despertado muito interesse da comunidade científica recentemente, principalmente em aplicações de bioenergia. Um desses compostos é o 5-hidroximetilfurfural ou HMF, o qual apresenta um alto potencial como matéria-prima na produção de biocombustíveis e produtos químicos de alto valor agregado, como polímeros e fármacos. A principal via para a obtenção de HMF é a desidratação de mono e polissacarídeos em meio ácido em um reator bifásico. A fase aquosa reacional contém um catalisador ácido e um açúcar, e a fase orgânica extrativa é formada por um solvente alcoólico parcialmente miscível com água que extrai continuamente o composto. Uma revisão de literatura revelou que o processo industrial ainda não é economicamente viável principalmente pela falta de dados termodinâmicos de equilíbrio associados à solubilidade durante a etapa extrativa, ou seja, à interação do HMF com água e solventes. Consequentemente, muita energia e reagentes são desperdiçados, juntamente com os coprodutos na tentativa de extrair de forma eficiente o HMF. Neste trabalho, avaliou-se a interação em mistura aquosa entre o HMF e três álcoois de diferentes cadeias carbônicas (1-pentanol, 1-hexanol e 1-heptanol) a temperatura de 25° C. Os coeficientes de distribuição e de seletividade foram empregados para avaliar a capacidade dos solventes de extrair o 5-hidroximetilfurfural da solução aquosa. Os resultados mostraram que o 1-pentanol apresentou melhor desempenho entre os álcoois estudados para a recuperação de HMF a partir da água. Já o modelo NRTL foi usado para correlacionar os dados experimentais e os parâmetros de interação binária relevantes. O desvio médio quadrático da raiz (RMSD) do modelo NRTL foi de 0,78%, o que indica que os dados experimentais do ELL podem ser correlacionados satisfatoriamente pelo modelo. / The building block composts\' production from carbohydrates is currently attracting the attention of the research community, especially because they could be used as bioenergy. One of those composts is 5-hydroximetilfurfural, or HMF, which has a high potential as crude matter in biofuels as well as in medicine and also in polymers\' production. The easiest way to obtain HMF is by oligosaccharides dehydration using an acid medium at a biphasic reactor. In the aqueous phase, there are an acid catalyser and a sugar, and in the extractive organic phase, there is an alcoholic solvent that is partially miscible with water, were HMF is extracted continuously. A literature review showed that the industrial extraction process is not yet economically attractive. That happens due to missing thermodynamic data that would guarantee a successful extraction, such as the liquid-liquid equilibrium (LLE) data from the HMF, water and alcohol system. By improving the LLE in the extraction phase utilising a correct and efficient alcohol, we can increase the system efficiency: more HMF and less unwanted by-products extraction and a decrease in the energy consumption. Having those things in mind, in this research solubility graphics and LLE data between HMF, water, alcohol (1-pentanol, 1-hexanol e 1-heptanol) at 298,15 K and ~0,1 MPa were determined experimentally. The distribution coefficients and selectivities were employed to assess the capacity of solvents to extract 5hydroxymethylfurfural from aqueous solution. 1-pentanol showed better performance than the other studied alcohols for 5-hydroxymethylfurfural recovery from water. The NRTL model was used to correlate the experimental data and relevant binary interaction parameters were regressed. The root mean square deviations (RMSD) of the NRTL model was around 0.78%, which indicate that the experimental LLE data can be successfully correlated by model.

A produção de compostos a partir de carboidratos conhecidos como blocos de construção tem despertado muito interesse da comunidade científica recentemente, principalmente em aplicações de bioenergia. Um desses compostos é o 5-hidroximetilfurfural ou HMF, o qual apresenta um alto potencial como matéria-prima na produção de biocombustíveis e produtos químicos de alto valor agregado, como polímeros e fármacos. A principal via para a obtenção de HMF é a desidratação de mono e polissacarídeos em meio ácido em um reator bifásico. A fase aquosa reacional contém um catalisador ácido e um açúcar, e a fase orgânica extrativa é formada por um solvente alcoólico parcialmente miscível com água que extrai continuamente o composto. Uma revisão de literatura revelou que o processo industrial ainda não é economicamente viável principalmente pela falta de dados termodinâmicos de equilíbrio associados à solubilidade durante a etapa extrativa, ou seja, à interação do HMF com água e solventes. Consequentemente, muita energia e reagentes são desperdiçados, juntamente com os coprodutos na tentativa de extrair de forma eficiente o HMF. Neste trabalho, avaliou-se a interação em mistura aquosa entre o HMF e três álcoois de diferentes cadeias carbônicas (1-pentanol, 1-hexanol e 1-heptanol) a temperatura de 25° C. Os coeficientes de distribuição e de seletividade foram empregados para avaliar a capacidade dos solventes de extrair o 5-hidroximetilfurfural da solução aquosa. Os resultados mostraram que o 1-pentanol apresentou melhor desempenho entre os álcoois estudados para a recuperação de HMF a partir da água. Já o modelo NRTL foi usado para correlacionar os dados experimentais e os parâmetros de interação binária relevantes. O desvio médio quadrático da raiz (RMSD) do modelo NRTL foi de 0,78%, o que indica que os dados experimentais do ELL podem ser correlacionados satisfatoriamente pelo modelo. / The building block composts\' production from carbohydrates is currently attracting the attention of the research community, especially because they could be used as bioenergy. One of those composts is 5-hydroximetilfurfural, or HMF, which has a high potential as crude matter in biofuels as well as in medicine and also in polymers\' production. The easiest way to obtain HMF is by oligosaccharides dehydration using an acid medium at a biphasic reactor. In the aqueous phase, there are an acid catalyser and a sugar, and in the extractive organic phase, there is an alcoholic solvent that is partially miscible with water, were HMF is extracted continuously. A literature review showed that the industrial extraction process is not yet economically attractive. That happens due to missing thermodynamic data that would guarantee a successful extraction, such as the liquid-liquid equilibrium (LLE) data from the HMF, water and alcohol system. By improving the LLE in the extraction phase utilising a correct and efficient alcohol, we can increase the system efficiency: more HMF and less unwanted by-products extraction and a decrease in the energy consumption. Having those things in mind, in this research solubility graphics and LLE data between HMF, water, alcohol (1-pentanol, 1-hexanol e 1-heptanol) at 298,15 K and ~0,1 MPa were determined experimentally. The distribution coefficients and selectivities were employed to assess the capacity of solvents to extract 5hydroxymethylfurfural from aqueous solution. 1-pentanol showed better performance than the other studied alcohols for 5-hydroxymethylfurfural recovery from water. The NRTL model was used to correlate the experimental data and relevant binary interaction parameters were regressed. The root mean square deviations (RMSD) of the NRTL model was around 0.78%, which indicate that the experimental LLE data can be successfully correlated by model.

Dados experimentais de algumas propriedades de componentes do biodiesel nÃo podem ser obtidos experimentalmente ou sÃo escassos. Com isso, a utilizaÃÃo de mÃtodos preditivos torna-se fundamental para o cÃlculo de propriedades fÃsicas e termodinÃmicas de Ãsteres que compÃem o biodiesel. Neste trabalho, foram avaliados mÃtodos para o cÃlculo de propriedades crÃticas e do fator acÃntrico atravÃs do cÃlculo da densidade utilizando a equaÃÃo de Rackett-Soave. MÃtodos para o cÃlculo da temperatura normal de fusÃo e temperatura normal de ebuliÃÃo tambÃm foram avaliados. Os mÃtodos avaliados para a temperatura normal de fusÃo nÃo apresentaram bons resultados, com isso correlaÃÃes para esta propriedade foram propostas. TrÃs versÃes do mÃtodo GCVOL foram avaliadas, juntamente com a equaÃÃo de Rackett-Soave, para o cÃlculo da densidade de biodiesel. As quatro equaÃÃes apresentaram-se satisfatÃrias. PorÃm, a equaÃÃo de Rackett-Soave foi a Ãnica que apresentou comportamento fisicamente consistente para a densidade a altas temperaturas. A partir disso, a equaÃÃo de Rackett-Soave foi estendida para altas pressÃes. Dois modelos baseados no princÃpio dos estados correspondentes (Carmo1F e Carmo2F) foram propostos para a prediÃÃo de viscosidade de Ãsteres e biodiesel. O modelo de Ceriani tambÃm foi avaliado. Os modelos Carmo1F e Carmo2F apresentaram bons resultados para a viscosidade de biodiesel. No entanto, para Ãsteres o modelo de Carmo1F nÃo apresentou bons resultado e por isso nÃo deve ser utilizado para esse tipo de composto. O modelo de Carmo2F apresentou bons resultados apenas para Ãsteres saturados. O modelo de Ceriani apresentou bons resultados para Ãsteres, mas resultados piores que os modelos de Carmo1F e Carmo2F foram encontrados para biodiesel. AlÃm disso, quatro mÃtodos de contribuiÃÃo de grupos para o coeficiente de atividade foram avaliados para sistemas de equilÃbrio lÃquido-lÃquido contendo biodiesel + glicerol + Ãlcool (metanol ou etanol). Os mÃtodos que apresentaram as melhores prediÃÃes foram o UNIFAC-Dortmund e ASOG. Por isso, eles sÃo os mÃtodos indicados para a simulaÃÃo de equilÃbrio lÃquido-lÃquido de sistemas contendo biodiesel. / Experimental data for some properties of biodiesel components cannot be obtained or are scarce. Therefore predictive methods are fundamental tools for calculating physical and thermodynamic properties of esters in biodiesel. In this work, methods for critical properties and acentric factor were evaluated by the Rackett-Soave for density calculations. Methods for freezing temperature and boiling temperature have also been evaluated. Freezing temperature methods did not present good results. Therefore correlations were proposed for this property. Three versions of GCVOL method and the Rackett-Soave equation were evaluated for biodiesel density predictions. These four models presented satisfactory results. However, Rackett-Soave equation was the only that presented a physically consistent behavior for the density at high temperatures. Thereat, Rackett-Soave equation was extended to high pressures. Two models based on corresponding states principle (Carmo1F and Carmo2F) were proposed for viscosity predictions of esters and biodiesel. The Cerianiâs model was evaluated too. Carmo1F and Carmo2F models obtained good results for biodiesel viscosity. However, the Carmo1F model did not present good results for esters and, for this reason, this model should not be used for these components. The Carmo2F model presented good predictions for saturated esters viscosity. The Cerianiâs model presented good results for ester, but in comparison to Carmo1F and Carmo2F models, worse results have been obtained for biodiesel. Furthermore, four group contributions methods for activity coefficient were evaluated for liquid-liquid equilibrium systems composed of biodiesel + glycerol + alcohol (methanol or ethanol). The models that have output the best predictions were the UNIFAC-Dortmund and ASOG models. As such, these two models are recommended to simulated liquid-liquid equilibrium of biodiesel containing systems.

Vapour-Liquid Equilibrium (VLE), Liquid-Liquid Equilibrium (LLE) and Vapour-Liquid-Liquid Equilibrium (VLLE) are of special interest in chemical engineering as these types of data form the basis for the design and optimization of separation processes such as distillation and extraction, which involve phase contacting. Of recent, chemical companies/industries have required thermodynamic data (especially phase equilibrium data) for chemicals that are expensive or costly to synthesize. Phase equilibrium data for such chemicals are scarce in the open literature since most apparatus used for phase equilibrium measurements require large volumes (on average 120 cm3) of chemicals. Therefore, new techniques and equipment have to be developed to measure phase equilibrium for small volumes across reasonable temperature and pressure ranges. This study covers the design of a new apparatus that enables reliable vapour pressure and equilibria measurements for multiple liquid and vapour phases of small volumes (a maximum of 18 cm3). These phase equilibria measurements include: VLE, LLE and VLLE. The operating temperature of the apparatus ranges from 253 to 473 K and the operating pressure ranges from absolute vacuum to 1600 kPa. The sampling of the phases are accomplished using a single Rapid-OnLine-Sampler- Injector (ROLSITM) that is capable of withdrawing as little as 1μl of sample from each phase. This ensures that the equilibrium condition is not disturbed during the sampling and analysis process. As an added advantage, a short equilibrium time is generally associated with a small volume apparatus. This enables rapid measurement of multiple phase equilibria. A novel technique is used to achieve sampling for each phase. The technique made use of a metallic rod (similar in dimension to the capillary of the ROLSITM) in an arrangement to compensate for volume changes during sampling. As part of this study, vapour pressure and phase equilibrium data were measured to test the operation of the newly developed apparatus that include the following systems: • VLE for 2-methoxy-2-methylpropane + ethyl acetate at 373.17 K • LLE for methanol + heptane at 350 kPa • LLE for hexane + acetonitrile at 350 kPa • VLLE for hexane + acetonitrile at 348.20 K New experimental vapour pressure and VLE data were also measured for systems of interest to petrochemical companies. These measurements include: • VLE for methanol + butan-2-one at 383.25, 398.14 and 413.20 K ABSTRACT • VLE for ethanol + butan-2-one at 383.26, 398.23 and 413.21 K • VLE for ethanol + 2-methoxy-2-methylbutane at 398.25 and 413.19 K • VLE for ethanol + 2-methylpent-2-ene at 383.20 K These measurements were undertaken to understand the thermodynamic interactions of light alcohols and carbonyls as part of a number of distillation systems in synthetic fuel refining processes which are currently not well described. Two of these above mentioned systems include expensive chemicals: 2-methoxy-2-methylbutane and 2-methylpent-2-ene. The experimental vapour pressure data obtained were regressed using the extended Antoine and Wagner equations. The experimental VLE data measured were regressed with thermodynamic models using the direct and combined methods. For the direct method the Soave-Redlich-Kwong and Peng-Robinson equations of state were used with the temperature dependent function (α) of Mathias and Copeman (1983). For the combined method, the virial equation of state with the second virial coefficient correlation of Tsonopoulos (1974) was used together with one of the following liquid-phase activity coefficient model: TK-Wilson, NRTL and modified UNIQUAC. Thermodynamic consistency testing was also performed for all the VLE experimental data measured where almost all the systems measured showed good thermodynamic consistency for the point test of Van Ness et al. (1973) and direct test of Van Ness (1995). / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2011.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Neste trabalho, estudou-se a extraÃÃo de Imunoglobulina G (IgG) em Sistemas Aquosos BifÃsicos (SABs) compostos por polietilenoglicÃis (PEG) com massas moleculares iguais a 4000, 6000 e 8000 g.mol-1 e tampÃo citrato com pHs 5,0, 6,0 e 7,0. Primeiramente, determinou-se o comportamento no equilÃbrio para cada sistema por duas metodologias diferentes: cloud-point, a partir do qual foram obtidas as curvas binodais, e densitometria, que deu origem Ãs linhas de amarraÃÃo. Os resultados obtidos por ambas as tÃcnicas apresentaram uma boa concordÃncia. Observou-se que o aumento da massa molar do PEG, bem como o aumento do pH do tampÃo citrato levou a um aumento da Ãrea sobre a curva binodal. Entretanto, para o Ãltimo caso, a expansÃo da regiÃo bifÃsica nÃo foi significante quando se aumentou o pH de 6,0 para 7,0. Em relaÃÃo Ãs linhas de amarraÃÃo, tambÃm nÃo foram observadas mudanÃas significativas tanto no comprimento como nas inclinaÃÃes das mesmas quando se variou a massa molar e o pH, o que mostra a alta capacidade dos Ãons citrato em se hidratar preferencialmente e promover quase totalmente ou totalmente a exclusÃo do PEG da fase fundo, como observado nesse trabalho. O estudo de partiÃÃo se deu a partir de um planejamento estatÃstico do tipo 24 com resoluÃÃo completa e adiÃÃo de trÃs pontos centrais, tendo como variÃveis a % PEG, % tampÃo citrato, pH e massa molar do PEG. Para tal finalidade o software Statistica 7 foi utilizado. Foram realizados 19 experimentos e cada variÃvel independente foi testada em trÃs nÃveis, sendo os valores de porcentagem de PEG iguais a 26, 28 e 30% m/m e de tampÃo citrato iguais 8, 10 e 12% m/m. Os experimentos que apresentaram os maiores valores de coeficiente de partiÃÃo (Kp) foram aqueles com pH 7,0 e 12% de tampÃo citrato, classificados como fatores significativos estatisticamente. Fixaram-se, entÃo, esses valores de pH e % de tampÃo citrato e realizaram-se mais 27 experimentos com diferentes concentraÃÃes de NaCl (0, 0,2 e 0,4 M). Observou-se um aumento no valor de Kp quando se aumentou a concentraÃÃo de NaCl. Os resultados apresentados neste estudo mostraram que elevados valores de Kp podem ser obtidos mesmo a baixas concentraÃÃes de sal neutro. Este resultado mostrou ser satisfatÃrio visto que a utilizaÃÃo de grandes concentraÃÃes de sais em um processo industrial pode ocasionar diversos problemas como, por exemplo, a reduÃÃo na vida Ãtil dos equipamentos devido à corrosÃo dos mesmos. / In this work, it was studied the extraction of immunoglobulin G (IgG) in Aqueous Two Phase Systems (ATPS) composed of polyethylene glycols (PEG) with molecular weight equal to 4000, 6000 and 8000 g.mol-1 and citrate buffer with pH 5.0, 6.0 and 7.0. First, the behavior for each system in equilibrium was determined by two different methodologies: cloud-point from which binodal curves were obtained and density, which led to the tie-lines. The results obtained by both techniques showed good agreement. It was observed that the increase in PEG molecular weight and the increase in citrate buffer pH led to an increase in the area of the binodal curve. However, for the latter case, the expansion of two-phase region was not significant when the pH increased from 6.0 to 7.0. Regarding the tie-lines, there were also no significant changes in both length and slopes of the same while varying the molecular weight and pH, which shows the high ability of citrate ions on hydrating theirselves preferably and promoting fully or almost fully the PEG exclusion bottom phase, as observed in this study. The study of partition was made from a statistical design of type 24 with complete resolution and adding three central points, having as variables % PEG, % citrate buffer, pH and PEG molar mass. For this purpose the software Statistica 7 was used. 19 experiments were performed and each independent variable was tested in three levels, being the values of PEG percentage equals to 26, 28 and 30% (m/m) and citrate buffer percentage equals to 8, 10 and 12% (w/w). The experiments showed that the highest values of the partition coefficient (Kp) were obtained in systems with pH 7.0 and 12% citrate buffer, classified as statistically significant factors. These values of pH and % citrate buffer were settled and other 27 experiments were conducted with different concentrations of NaCl (0, 0.2 and 0.4 M). There was an increase in the Kp value when the NaCl concentration increased. The results of this study showed that high Kp values can be obtained even at low concentrations of neutral salt. This result is satisfactory since the use of high concentrations of salts in an industrial process may cause various problems such as the reduction in service life due to corrosion of the equipment thereof.

Orientadores: Maria Regina Wolf Maciel, Martín Aznar / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-17T10:23:34Z (GMT). No. of bitstreams: 1 Machado_AlexBarreto_D.pdf: 10485061 bytes, checksum: 1bbe757a7cc410835bff5b7be09c251b (MD5) Previous issue date: 2010 / Resumo: Vários são os interesses que têm impulsionado o investimento em novos processos de produção de fontes alternativas de energia: preocupação com o esgotamento de fontes limitadas de petróleo; dependência do mercado brasileiro de recursos estrangeiros, apelo a fontes renováveis de matéria prima e preocupações ambientais (Protocolo de Kyoto). Dentre as alternativas aos combustíveis fósseis, o biodiesel aparece como uma alternativa promissora. O biodiesel pode ser definido como sendo um mono-alquil éster de ácidos graxos derivado de fontes renováveis, como óleos e gorduras, obtido através de processo de transesterificação, no qual ocorre a transformação de triacilgliceróis em moléculas menores de ésteres de ácidos graxos, rendendo como subproduto o glicerol (ou glicerina). O biodiesel encontra-se registrado na Environmental Protection Agency (EPA-USA) como combustível e como aditivo para combustíveis e pode ser usado puro a 100% (B100), em mistura com o diesel de petróleo, por exemplo de 20% (B20), ou em uma proporção baixa (1 a 5%) como aditivo, sendo o seu uso possível sem nenhuma modificação nos motores convencionais. Inúmeros trabalhos vêm sendo desenvolvidos testando diferentes óleos, processos e misturas finais, mas para a correta avaliação destes trabalhos torna-se necessário caracterizar o produto obtido e reconhecer as diferenças presentes nas matérias primas capazes de alterar positivamente o resultado final. Além disso, torna-se necessário entender os equilíbrios líquido-líquido formados com as misturas e estudar os equilíbrios líquido-vapor envolvidos nas destilações necessárias para a purificação do biodiesel. Tais dados não são encontrados na literatura atualmente e inviabilizam a construção de plantas virtuais e a realização de simulações computacionais. Assim, o presente projeto visa apresentar uma caracterização de sistemas envolvidos na purificação do biodiesel, permitindo obter dados de equilíbrios líquido-líquido e líquido-vapor em sistemas contendo etanol, glicerol, biodiesel de óleo de soja (Bio-OS), biodiesel de óleo de mamona ( Bio-OM ), água e catalisador / Abstract: There are several concerns that have driven investment in new production processes for alternative energy sources: concern over the depletion of limited supplies of oil, dependence on the Brazilian market of foreign funds, call for renewable raw materials and environmental concerns (Protocol Kyoto). Among the alternatives to fossil fuels, biodiesel appears as a promising alternative. Biodiesel can be defined as a mono-alkyl ester of fatty acids derived from renewable sources such as vegetable oils and animal fats obtained through transesterification process, which occurs in the transformation of triacylglycerols into smaller molecules of fatty acid esters, yielding as a byproduct glycerol (or glycerin). Biodiesel is registered with the Environmental Protection Agency (EPA-USA) as fuel and fuel additive and can be used at 100% (B100), mixed with petroleum diesel, for example, 20% (B20) or in a low proportion (1-5%) as an additive, which makes their use possible without any modification in conventional engines. Numerous studies have been developed by testing different oils, processes and final mixtures, but for proper assessment of this work, it is necessary to characterize the product and recognize the differences present in the raw materials that can positively change the outcome. Moreover, it is necessary to understand the liquid-liquid equilibria formed with the mixtures and to study the vapor-liquid equilibria involved in distillation required for the purification of biodiesel. Such data are not found in the open literature and currently hinder the construction of virtual plants and conducting computer simulations. Thus, this project aims to present a characterization of systems involved in the purification of biodiesel, allowing to get data from liquid-liquid equilibria and vapor-liquid systems containing ethanol, glycerol, biodiesel from soybean oil ( Bio-SO) and biodiesel from castor oil ( Bio-CO), water and catalyst (NaOH) / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Orientadores: Eduardo Augusto Caldas Batista, Marcelo Lanza / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T08:03:01Z (GMT). No. of bitstreams: 1 Silva_CesarAugustoSodreda_D.pdf: 1528934 bytes, checksum: 876115f0d607a9ede4187d15d39c0054 (MD5) Previous issue date: 2011 / Resumo: O presente trabalho teve como objetivo a investigação do comportamento de fases através da determinação de dados de equilíbrio líquido-líquido em diferentes sistemas graxos envolvidos na produção e purificação de biodiesel, além da correlação e avaliação desses dados empregando o modelo termodinâmico NRTL (non¿random, two¿liquid). Inicialmente, foram medidos experimentalmente os dados de equilíbrio líquido¿líquido para sistemas binários e ternários envolvendo óleo vegetal + etanol + água, onde foram determinadas as linhas de solubilidade mútua, em uma faixa de temperatura de 25 ºC a 60 ºC. Os óleos vegetais investigados foram: óleo de canola, óleo de milho, óleo de pinhão manso (Jatropha curcas), e óleo de polpa de macaúba (Acrocomia aculeata). De acordo com os resultados, o aumento da temperatura dentro das condições experimentais analisadas favoreceu a miscibilidade óleo¿solvente em ambas as fases. Em uma segunda etapa, dados de equilíbrio líquido¿líquido para sistemas ternários e quaternários empregados no processo de desacidificação de óleos vegetais foram determinados. Tais dados de equilíbrio foram gerados em diferentes condições de temperatura e porcentagens de água no solvente. Os sistemas investigados foram: óleo de polpa de macaúba + ácido oléico + etanol + água e óleo de pinhão manso + ácido oléico + etanol + água. Os resultados mostraram que o coeficiente de distribuição do ácido oléico entre as fases foi mais afetado pelo conteúdo de água no solvente do que pela temperatura. Finalmente, foram determinados dados de equilíbrio líquido¿líquido para sistemas ternários de interesse na purificação de ésteres etílicos (biodiesel), produzidos pela transesterificação alcalina do óleo da polpa de macaúba. Os sistemas investigados foram: biodiesel de macaúba + etanol + glicerol e biodiesel de macaúba + etanol + água; sistemas encontrados durante a separação e a lavagem do biodiesel com água, respectivamente. Os resultados obtidos no processo de separação do biodiesel mostraram que o etanol é completamente solúvel no biodiesel e no glicerol, enquanto que o glicerol apresenta uma baixa solubilidade no biodiesel. Para o processo de lavagem do biodiesel, o aumento da temperatura, dentro da faixa estudada (25 ºC a 45 ºC), não contribuiu para a redução da região bifásica. Todos os dados de equilíbrio foram correlacionados utilizando o modelo NRTL, sendo o desvio global entre os dados calculados e experimentais inferior a 0,99%, mostrando a boa qualidade descritiva e aplicabilidade do modelo NRTL na análise de dados de equilíbrio líquido¿líquido / Abstract: This study aimed to investigate the phase behavior of liquid¿liquid equilibrium data for systems of relevance in biodiesel production and purification, as well as their correlation using the NRTL model (non¿random, two¿liquid). Initially, experimental liquid¿liquid equilibrium data were determined for binary and ternary systems composed of vegetable oil + ethanol + water, in which mutual solubility between vegetable oils and aqueous ethanol or anhydrous ethanol were investigated, at temperatures ranging from 25 ºC to 60 º C. The following vegetable oils were investigated: canola oil, corn oil, Jatropha curcas oil and macauba (Acrocomia aculeata) pulp oil. According to the results, an increase in temperature within the study ranges led to an increase in oil¿solvent miscibility in both phases. In the second part of this work, liquid¿liquid equilibrium data for systems of interest in deacidification of vegetable oils were experimentally determined. These equilibrium data were analyzed in different temperature conditions and water mass fractions in the solvent. The following systems were investigated: macauba pulp oil + oleic acid + ethanol + water and Jatropha curcas oil + oleic acid + ethanol + water. The results indicated that the oleic acid distribution coefficients were more affected by water content in the alcoholic solvent than by temperature. Finally, liquid¿liquid equilibrium data for systems of interest in biodiesel purification were measured. The biodiesel were produced by transesterification of macauba pulp oil with ethanol, using KOH as a homogeneous catalyst. In these studies, the following systems were investigated: macauba biodiesel + glycerol + ethanol and macauba biodiesel + ethanol + water. These systems are found in the separation and washing of biodiesel with water, respectively. From the results, it can be observed that biodiesel and glycerol were partially soluble in each other; however, the solubility of biodiesel in the glycerol phase was slightly greater than that of glycerol in the biodiesel phase. In the washing process of biodiesel, an increase in temperature within the range studied (25 ° C to 45 ° C) did not contribute to a reduction in biphasic region. The liquid¿liquid equilibrium experimental data were correlated using the NRTL model. In all these systems, the global deviations between calculated and experimental data were lower than 0.99 %, showing the good descriptive quality and applicability of the NRTL model in liquid¿liquid equilibrium data analyses / Doutorado / Engenharia de Alimentos / Doutor em Engenharia de Alimentos