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As renewable lignin building blocks, hydroxystyrenes are particularly appealing as either a replacement or addition to styrene-based polymer chemistry. These monomers are obtained by decarboxylation of phenolic acids and often subjected to chemical modifications of their phenolic hydroxy groups to improve polymerization behaviour. Despite efforts, a simple, scalable, and purely (chemo)catalytic synthesis of acetylated hydroxystyrenes remains elusive. We thus propose a custom-made chemoenzymatic route that utilizes a phenolic acid decarboxylase (PAD). Our process development strategy encompasses a computational solvent assessment informing about solubilities and viable reactor operation modes, experimental solvent screening, cascade engineering, heterogenization of biocatalyst, tailoring of acetylation conditions, and reaction upscale in a rotating bed reactor. By this means, we established a clean one-pot two-step process that uses the renewable solvent CPME, bio-based phenolic acid educts and reusable immobilised PAD. The overall chemoenzymatic reaction cascade was demonstrated on a 1 L scale to yield 18.3 g 4-acetoxy-3-methoxystyrene in 96% isolated yield. © 2022 The Royal Society of Chemistry.

Orientador: Roberta Ceriani Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química Resumo: Os óleos vegetais comestíveis fazem parte da dieta tradicional da maioria dos povos. Além de conferirem cor e sabor, e melhorarem consideravelmente a aparência dos alimentos, são também fontes de energia, ácidos graxos essenciais, vitaminas e antioxidantes lipossolúveis. O óleo de semente de girassol destaca-se por apresentar elevados teores de ácido linoleico, um ácido graxo essencial, e compostos nutracêuticos (tocoferóis, por exemplo), os quais são eficientes para a manutenção da saúde humana e prevenção de inúmeras doenças. A etapa de desodorização do processo de refino de óleos/gorduras tem a função de remover compostos odoríferos, resultantes principalmente da oxidação do óleo, e também contaminantes, como pesticidas. Tradicionalmente, nesse processo são empregadas temperaturas elevadas e alto vácuo, causando degradação e volatilização de antioxidantes, perda de óleo neutro por volatilização, reações de oxidação e isomerização cis-trans de ácidos graxos insaturados, dentre outras. Uma alternativa ao processo tradicional por esgotamento com arraste a vapor é a aplicação da extração líquido-líquido. Comparada à ele, a mesma consome menor quantidade de energia e tem a vantagem de poder ser realizada em condições ambientes de temperatura e pressão, minimizando os efeitos danosos das elevadas temperaturas do processo tradicional. Na continuidade do trabalho de Homrich (2014), que determinou dados de equilíbrio líquido-líquido de sistemas modelos formados por óleo de semente de girassol + aldeídos (n-pentanal, n-hexanal, 2-nonenal e 2,4-decadienal) + etanol anidro a 25 °C, nesse trabalho outros três compostos odoríferos foram investigados, sendo eles ácidos carboxílicos de cadeia curta (ácido butanoico, ácido pentanoico e ácido octanoico). As quantificações das frações mássicas das fases em equilíbrio nas linhas de amarração foram feitas por evaporação em estufa a vácuo para o solvente e titulação para o soluto. Os dados experimentais foram correlacionados pelos modelos NRTL e UNIQUAC. A capacidade preditiva dos métodos UNIFAC-LL de Magnussen et al. (1981) e UNIFAC-FS (UNIFAC modificado por Hirata et al., 2013) também foram averiguadas. Num contexto mais amplo, esse projeto de mestrado está inserido na linha de pesquisa que investiga uma alternativa ao processo de desodorização tradicional, combinando uma etapa de extração líquido-líquido seguida de uma desodorização mais branda em termos de temperatura, evitando efeitos danosos à qualidade do óleo refinado Abstract: Edible oils are part of traditional diet of most people. Besides promoting color and flavor, and greatly improve the appearance of food, they also are sources of energy, essential fatty acids, vitamins and fat-soluble antioxidants. Sunflower seed oil stands out for presenting high levels of linoleic acid, an essential fatty acid, and nutraceutical compounds (tocopherols, for example), which are effective for the maintenance of human health and prevention of many diseases. Deodorization step of the oils/fats refining process has the function of removing odoriferous compounds resulting mainly from oil oxidation, and contaminants, such as pesticides. Traditionally, in this process high temperatures and high vacuum are employed, causing degradation and volatilization of antioxidants, loss of neutral oil by volatilization, oxidation reactions and cis-trans isomerization of unsaturated fatty acids. An alternative to the traditional process by steam stripping is the application of liquid-liquid extraction. Compared to traditional process, it consumes lower amounts of energy and has the advantage of being carried out under ambient conditions of temperature and pressure, while minimizing the damaging effects of high temperatures. Continuing the work of Homrich (2014), in which liquid-liquid equilibrium data of model systems formed by sunflower seed oil + aldehydes (n-pentanal, n-hexanal, 2-nonenal and 2,4-decadienal) + anhydrous ethanol at 25 °C were determined, in this study three other odoriferous compounds were investigated, i.e., short-chain carboxylic acids (butanoic acid, pentanoic acid and octanoic acid). Quantifications of mass fraction of equilibrium phases within tie lines were obtained by evaporation in vacuum oven for solvent, and by titration for solute. Experimental data were correlated by the NRTL and UNIQUAC models. Predictive capability of UNIFAC-LL (Magnussen et al., 1981) and UNIFAC-FS (modified by Hirata et al., 2013) methods were also ascertained. In a broader context, this project is part of an investigation dealing with development of an alternative for traditional deodorization process, combining a liquid-liquid extraction step followed by a milder deodorization in terms of temperature, avoiding its detrimental effects on refined oil quality Doutorado Engenharia Química Mestra em Engenharia Química CAPES 33003017034P8

Optimization of the extraction process for reducing aromatic and/or polyaromatic compounds is of primary interest in crude oil refining. Several solvents are described for carrying out such operations (furfural, N-methyl-pyrrolidone -NMP-, dimethyl-sulfoxide -DMSO-, …) and experimental data and model description are required for the correct design of the separation operations and the optimization of the conditions. In this work, liquid-liquid equilibria (LLE) data were determined for oil multicomponent mixtures formed by n-dodecane + mono-aromatic + poly-aromatic with NMP at ambient temperature (298.15 K) and pressure and covering a wide range of the solvent/oil ratios. A new analytical method based on NMR was developed, calibrated, and tested to fully determine the composition of equilibrium phases despite the high number of compounds. Obtained values for distribution constants and selectivities are higher than one and ranging 1-15, respectively, for aromatic compounds and even higher for polyaromatic components. Thus NMP appears as a suitable solvent for carrying both separations. The experimental data were predicted by several versions of the UNIFAC model, including the UNIFAC, modified UNIFAC (Dortmund), modified UNIFAC (NIST), and UNIFAC, including fitting parameters. Overall, modified UNIFAC (Dortmund) yields the best results, even when deviations obtained for some of the compositions are around 40% of the value, and simulations carried out with such models should be considered cautiously

The suitability of two promising solvents for the extraction of furfural from aqueous streams is assessed through novel quaternary and ternary liquid-liquid equilibria data for mixtures of solvent (2-methyltetrahydrofuran or cyclopentyl methyl ether) + acetic acid + furfural + water. The measured data between 298 and 343 K at atmospheric pressure are reported along with regressed binary interaction parameters for UNIQUAC-HOC activity coefficient model and further analyzed through distribution coefficients and selectivity for both acetic acid and furfural. Cyclopentyl methyl ether shows promising characteristics towards selective furfural extraction from a stream containing both studied solutes. Distribution coefficients below 1 are observed for acetic acid and as high as 9 for furfural in the quaternary mixtures.

In this work, the phase equilibria of the system comprised of isophorone, furfural, water and acetic acid were studied from the viewpoint of the extraction process. Equilibrium vapor pressure of pure isophorone was measured at sub-atmospheric pressure. Isobaric (at 40 kPa) isophorone-furfural vapor-liquid equilibria, the excess enthalpy of isophorone-furfural mixture (at 323 K) and isophorone-acetic acid vapor-liquid equilibria (from 322 K to 342 K) were investigated and compared to the available literature data. Liquid-liquid equilibria of systems comprised of isophorone-furfural-water (from 303 K to 343 K) were measured for the first time. The experimental results of this study and the literature values were utilized for optimizing the parameters for UNIQUAC model. The model was validated against the measured liquid-liquid equilibrium of the quaternary system isophorone-furfural-acetic acid-water (from 298 K to 343 K). Isophorone was found to be a favorable solvent for furfural extraction from its aqueous solutions.

Liquid–liquid equilibrium for eight ternary systems involving one hydrocarbon (n-hexane, n-heptane, i-octane or toluene), thiophene or pyridine and an ionic liquid (1-hexyl-3, 5-dimethylpyridinium bis(trifluoromethylsulfonyl)imide) was experimentally determined at atmospheric pressure and 25°C. Equilibrium data are presented with binodal curves as well as with tie lines. The suitability of ionic liquid (IL) for extractive desulfurization and denitrification was evaluated in terms of solute distribution ratio and selectivity. Extraction experiments with three-component and seven-component (n-hexane, n-heptane, i-octane, toluene, thiophene, pyridine and IL) systems have been performed. The equilibrium data in three-component systems were well described with Non-Random Two-Liquid (NRTL) and Universal Quasi-Chemical (UNIQUAC) models.

The phase equilibrium data for methanol + ethanol + isooctane systems were obtained at 303.15 K. Data for methanol + ethylbenzene + isooctane system were taken from literature. The effect of ethanol addition on the system equilibrium was investigated at the same temperature. The distribution curves for ternary and quaternary system was analyzed. The experimental results for ternary systems were correlated with UNIQUAC and NRTL equations. For the ternary systems studied here, the NRTL equation is more accurate than the UNIQUAC. The equilibrium data for the three ternary systems were used to determine interactions parameters for the UNIQUAC equation. For the quaternary system, the experimental data can be fitted more accurately to UNIQUAC equation than by the UNIFAC method. Fil: Gramajo, Monica Beatriz. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; Argentina Fil: Veliz, Jonatan Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física; Argentina Fil: Cases, Alicia Marta. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; Argentina

In this work, the liquid - liquid and solid - liquid phase behaviour of ten aqueous pseudo-binary and three binary systems containing polyethylene glycol 2050, polyethylene glycol 35000, aniline, N,N-dimethylaniline and water, in the temperature range T = (298.15 to 350.15) K and at ambient pressure of 0.1 MPa, was studied. The obtained temperature-composition phase diagrams showed that the only functional co-solvent was PEG2050 for aniline in water, while PEG35000 even showed a clear anti-solvent effect in the N,N-dimethylaniline aqueous system. The experimental SLE data have been correlated by the Non-Random Two-Liquid (NRTL) model, and the correlation results are in accordance with the experimental results. [Projekat Ministarstva nauke Republike Srbije, br. 172063]

The ability of binary deep eutectic solvent choline chloride+1,2-propanediol (DES1; 1 : 3 mole ratio) and ternary deep eutectic solvent choline chloride+1,2-propanediol+water (DES2; 1 : 3 : 3 mole ratio) for breaking the azeotropes hexane/heptane+ethanol by means of liquid-liquid extraction was evaluated. Liquid-liquid equilibrium experiments were performed at 298.15 K, at atmospheric pressure, and data were correlated by NRTL and UNIQUAC models. Thermodynamic properties (density, viscosity, refractive index and speed of sound) of DES1 and DES2 were determined in temperature range from 288.15 K to 333.15 K and at atmospheric pressure. Extraction ability of the investigated eutectics yielded promising results in comparison with conventional solvents. Besides a high selectivity towards ethanol, an advantage of DES2 is its lower viscosity and higher distribution ratio values, which is an important aspect for a potential industrial application. Another advantage of both investigated eutectics is their easy and high recoverability from the extract layer based on their negligible vapor pressure.

Phase equilibria of oxygen-bearing aromatic compounds, hydrocarbons and water mixtures are of essential interest in many processes using feeds originating from biomass. The strong non-ideal thermodynamic behavior of these systems sometimes results in immiscibility with both water and alkanes. To address this problem, the GC-PPC-SAFT equation of state [Tamouza et al., 2004; Nguyen-Huynh et al., 2008a ] is extended to some selected components: phenol, alkyl-phenols, alkyl-benzoates, benzaldehyde and anisole. However, as in these multifunctional compounds, the proximity of polar functional groups may result in a lack of transferability of the parameters from the monofunctional homologous species, some parameters have been adapted in view of physical arguments. Next, liquid–vapour and liquid–liquid equilibria of mixtures with n-alkanes were evaluated, using a predictive method for the binary interaction parameters ( k ij ) [ Nguyen-Huynh et al., 2008b ]. Finally, mixtures with other associating compounds, as alcohols and water have also been considered. In all cases, both correlations and predictions are qualitatively and quantitatively satisfactory. The relative deviations obtained on bubble pressure of vapor–liquid equilibria are 4–8%, that is comparable to those obtained on previously investigated systems.

Liquid–liquid equilibria for the three-component systems with ionic liquid [C5mim][Tf2N] – (pyridine or thiophene) – hydrocarbon (toluene or n-hexane or n-heptane or i-octane) were determined at T = 298.15 K and atmospheric pressure. In addition, the applicability of [C5mim][Tf2N] as selective solvent for desulfurization, denitrification and dearomatization of a model six-component hydrocarbon solution as well as real refinery FCC gasoline was investigated on the laboratory scale. The equilibrium data in three-component and seven-component (model solution + ionic liquid) systems were well described with NRTL and UNIQUAC models. The suitability of ionic liquid for extractive desulfurization and denitrification was evaluated in terms of solute distribution ratio and selectivity, as well as extraction effectiveness.

The ability of non-toxic and biodegradable deep eutectic solvent (DES) choline chloride + DL-malic acid in mole ratio 1:1, for the breaking of the azeotropes heptane + methanol and toluene + methanol by means of liquid– –liquid extraction was evaluated. Ternary liquid–liquid equilibrium experiments were performed at 298.15 K and at atmospheric pressure. Densities, viscosities and refractive indices of DES + methanol and water + DES systems were experimentally determined over a wide temperature range and at atmospheric pressure. Additionally, the viscosities of DES + glycerol mixture were - determined at temperatures up to 363.15 K to check how much the addition of glycerol decreases high viscosities of DES. The results indicate that the addition of small amounts of water or glycerol as a third component significantly decreases the viscosity of the investigated deep eutectic solvent. Based on the selectivity and distribution ratio values, the extraction ability of the investigated deep eutectic solvent, in comparison with the conventionally used solvents, yields promising results. Non-random two-liquid (NRTL) and universal quasichemical (UNIQUAC) models were satisfactorily applied for correlation of experimental phase equilibrium data for two ternary mixtures. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172063]

The ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMim][NTf2] was tested as solvent for the separation of benzene from a hexane + benzene mixture. The solvent ability was evaluated in terms of solute distribution ratio and selectivity. The extraction process was carried out in a laboratory-scale using a glass packed column and it was also simulated using conventional software.

Over the last two decades, ionic liquids have gained importance as alternative solvents to conventional VOCs in the field of homogeneous catalysis. This success is not only due to their ability to dissolve a large amount of metal catalysts, but it is also due to their potential to enhance yields of enantiopure products. The art of preparation of a specific enantiomer is a highly desired one and searched for in pharmaceutical industry. This work presents a study on solubility in water and in water/methanol mixture of a set of ILs composed of the bis (trifluoromethylsulfonyl) imide anion and of the N-alkyl-triethyl-ammonium cation (abbrev. [N R ,222][NTf2]) with the alkyl chain R ranging from 6 to 12 carbons. Mutual solubilities between ILs and water, as well as between ILs and methanol/water mixture were investigated in detail. These solubilities were measured using two well-known and accurate experimental techniques based on a volumetric and a cloud-point methods. Both methods enabled us to measure the Tx diagrams reflecting the mutual solubilities between water (or water/methanol) and selected ILs in the temperature range from 293.15 to 338.15 K. The data were fitted by using the modified Flory-Huggins equation proposed by de Sousa and Rebelo and compared also with the prediction carried out by the Cosmo-RS methodology

The phase diagram of the Poly- l -Lactic-Acid (PLLA), dioxane and water system was derived by using the lattice fluid model generalized for specific interactions. A qualitative analysis of Hansen solubility parameters together with empirical observations were adopted to reduce the number of adjustable parameters. The as-selected model parameters were derived by fitting a set of cloud point curves; consequently, the complete phase diagram of the system was computed. The use of specific interactions between species gave out a quantitative agreement with a set of experimental data, whereas changing the polymer polydispersity the agreement is only qualitative. In principle, the presented procedure could be adopted for the calculation of liquid–liquid equilibria in ternary polymer solutions with similar features of PLLA–dioxane–water system.

Ionic liquids are potential solvents for liquid extraction processes; thermodynamic modeling of liquid–liquid equilibrium (LLE) data is essential for the optimization and operation of these processes. Therefore, ternary LLE data in systems involving ionic liquids have been investigated by several years. In most of the cases, the thermodynamic modeling of these systems has been made using the NRTL model; in some cases, the UNIQUAC model has also been used. The structural parameters of UNIQUAC for ionic liquids have been determined either by empirical correlations or, more recently, through quantum mechanics calculation. This work is a continuation of a recent paper, in which the structural group volume and area parameters for the group-contribution UNIFAC method have been calculated for five ionic liquids following the quantum mechanics approach. In order to optimize the molecular geometry and to calculate the area and volume, the Density Functional Theory (DFT) and the Polarizable Continuum Method (PCM) were used, respectively. The obtained parameters were used to correlate LLE data for fifteen ternary systems, totalizing 155 tie-lines. New interaction parameters were also estimated between the solvent and the ionic liquid functional groups. The results are very satisfactory, with root mean square deviations 0.0037 between experimental and calculated equilibrium mole fractions.

Liquid–liquid phase separation processes are currently used as a route to prepare polymeric porous structures for various applications (membranes and scaffolds for tissue engineering). In membrane and foam fabrication technologies, binary and mainly ternary polymer solutions are used. Membrane morphology is strongly affected by phase equilibria of processing solution. In order to achieve a better control of membrane morphology and to explore a wide quantity of solvents, a predictive tool addressing experimentals would be strongly advisable. In this paper, group contribution models were chosen to test the applicability on a PLLA–dioxane–water ternary polymer solution, whose experimental data are available. As a general result, the inadequateness of models to predict the phase separation must be highlighted, coupled with a scarce sensitivity to temperature. Moreover, a major task stems about the free volume of water in relation to other components. A brief panoramic of attempts on various models and parameters is presented, underlining the open issues of the group contribution models.

International audience; Partial miscibility in binary systems {N-methylpiperidine–water} and {2-methylpiperidine–water} was studied. The temperatures of liquid–liquid separation were determined as function of composition using both calorimetric technique and phase equilibrium cell. The densities of {amine–water} mixtures were determined in the domain of total miscibility at temperatures between 288K and 338 K. Excess molar volumes were derived from experimental density data and fit to a Redlich–Kister polynomial.

The experimental liquid-liquid equilibrium data on propionic acid-water-solvent ternary mixtures at a temperature of 298.15 K are presented. The solvents are n-hexane, cyclohexane, cyclohexanol and cyclohexyl acetate. The distribution coefficients and separation factors are reported. The tie line data are correlated using the methods of Othmer-Tobias and Hand. The experimental results are compared with the values predicted by the UNIFAC group-contribution method.

In this work authors present the experimental liquid–liquid equilibria (LLE) data of water + ethanol + 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([bmim][Tf2N]) system at different temperatures. The LLE of the system was obtained in the temperature range from 283.2 to 323.2 K. The nonrandom two liquid (NRTL) and universal quasichemical (UNIQUAC) models were used to correlate ternary systems. The equilibrium compositions were successfully correlated by the interaction parameters from both models, however UNIQUAC gave a more accurate correlation. Finally, a study about the solvent capability of ionic liquid was made in order to evaluate the possibility of separating the mixture formed by ethanol and water using that ionic liquid. Financial support from the Ministerio de Ciencia y Tecnología of Spain, through Project No. CTQ2010-18848/PPQ and the FEDER European Program are gratefully acknowledged.

Vapour–liquid equilibria (VLE) of binary mixtures of n -perfluorohexane plus a n -alkane (C 5 –C 8 ) and of n -hexane plus a n -perfluoroalkane (C 5 –C 8 ) were determined using a head-space gas-chromatographic technique. Excess molar Gibbs energies, G E , for the systems investigated have been obtained by a least-square treatment of equilibrium data. Liquid–liquid equilibria (LLE) were determined by turbidimetry for n -perfluorohexane+ n -C n H 2 n +2 ( n =6–8) mixtures and the observed T – x curves compared with those predicted by the temperature dependence of activity coefficients. All mixtures show strong positive deviations from ideality, which increase with the size of the second component. Solute–solvent and solute–solute interactions have been examined by calculating and discussing solvation Gibbs energies and Kirkwood–Buff integrals. Perfluoroalkanes proved to be inert molecules that interact weakly with themselves as well as with alkanes.

Liquid–liquid equilibrium data for the ternary system 1-pentanol–ethanol–water have been determined experimentally at 25, 50, 85 and 95ºC. These results have been correlated simultaneously by the UNIQUAC method obtaining two sets of interaction parameters: one of them independent of the temperature and the other with a linear dependence. Both sets of parameters fit the experimental results well. The authors wish to thank the Generalitat Valenciana Spain for the financial help of the Project GV-3174r95 and to DGES for the financial aids of project PB96-0338.

Cilj ove doktorske disertacije je postavljanjematematičkog modela složenog trofaznog reakcionogsistem za epoksidovanje sojinog ulja in situ formiranompersirćetnom kiselinom iz sirćetne kiseline i vodonikperoksida u prisustvu jonoizmenjivačke smole kaokatalizatora. Model uzima u obzir koncentracijereaktanata i produkata u vodenoj i uljnoj fazi. Poredosnovnih reakcija stvaranja persirćetne kiseline iepoksida, model obuhvata i sporednu reakciju otvaranjaepoksi prstena sa sirćetnom kiselinom. Za modelovanjereakcije formiranja persirćetne kiseline na površinikatalizatora primenjeni su Langmuir-Hinshelwood-Hougen-Watson i Rideal-Eley postulati. Postavljenitrofazni model predstavlja sistem običnih diferencijalnihjednačina prvog reda koji opisuje promenu broja molovakomponenata i funkcionalnih grupa sa vremenomizvođenja procesa epoksidovanja, i sadrži više parametararazvrstanih na kinetičke, termodinamičke i parametre kojise odnose na prenos mase. Parametri modela zavise oduslova izvođenja epoksidovanja i to svi od temperature, aneki i od sastava i inteziteta mešanja.Za konstantu hemijske ravnoteže reakcije nastajanjapersirćetne kiseline je izvedena semiteorijska zavisnostod temperature koja daje vrednosti istog reda veličine iistog smera promene sa temperaturom kao i većinapodataka objavljenih u literaturi.Za izračunavanje koeficijenta raspodele sirćetne kiselineizmeđu uljne i vodene faze potrebno je odrediti zavisnostkonstante fazne ravnoteže tečno-tečno sirćetne kiseline odsastava i temperature. Utvrđeno je da je UNIFAC modelgrupnih doprinosa za koeficijente aktivnosti nepogodanza predskazivanje ravnoteže tečno-tečno. Eksperimentalnipodaci za ovu konstantu ravnoteže su uspešno korelisaniUNIQUAC modelom za koeficijente aktivnosti.Parametri reparametrizovane Arrheniusove zavisnostikonstanti brzina reakcija i konstanti sorpcije učesnikareakcije stvaranja persirćetne kiseline od temperatureodređeni su simultano sa parametrima koji se odnose naprenos mase i sa odnosom koeficijenata raspodelepersirćetne i sirćetne kiseline između uljne i vodene faze,fitovanjem eksperimentalnih podataka epoksidovanjasojinog ulja, tj. minimizacijom sume kvadrata odstupanjaračunskih od eksperimentalno određenih vrednosti jodnogbroja i sadržaja epoksi kiseonika tokom epoksidovanja.Fitovanje je uspešno izvedeno primenom metodeMarquardta, dok su pomenute računske vrednostidobijene numeričkom integracijom sistemadiferencijalnih jednačina modela primenom Runge-Kuttametode IV reda., The objective of this doctoral thesis was development ofmathematical model for complex three-phase reactionsystem for soybean oil epoxidation with peracetic acidformed in situ from acetic acid and hydrogen peroxide in apresence of an ion exchange resin as catalyst. The localconcentrations of components in water and oil phases wereintroduced into the model. In addition to reactions of theperacetic acid and epoxy compound formation, modelconsiders the side reaction of epoxy ring cleavage withacetic acid. Approximate modeling of peracetic acidformation was based on Langmuir-Hinshelwood-Hougen-Watson and Rideal-Eley postulates. Established threephasemodel is a system of ordinary first order differentialequations which describes change of components andfunctional groups amounts with reaction time. Besideskinetic parameters, model comprises the thermodynamicones as well as parameters of mass transfer between the oiland water phase. All model parameters are dependent ontemperature and some additionally on composition andintensity of stirring.A semitheoretical temperature dependency of chemicalequilibrium constant for peracetic acid formation wasestablished. The order of magnitude and temperature trendof the calculated chemical equilibrium constant are inagreement with the most data given in a literature.For calculation of partition coefficient for acetic acidbetween oil and water phase, temperature and compositiondependency of liquid-liquid equilibrium constant for aceticacid is necessary. It was found that UNIFAC model ofgroup contribution was non-applicable for the predictionof the equilibrium constant. The experimental data for theequilibrium constant were, however, successfully fitted byUNIQUAC model.Temperature dependencies of the reaction rate constantsand sorption constants of reactants and products inperacetic acid formation reaction are expressed byreparameterized Arrhenius equation. The parameters ofsuch equation were determined simultaneously with masstransfer parameters and ratio of peracetic acid and aceticacid partition coefficients between oil and water phase byfitting the experimental data i.e. by minimization of leastsum of squares of deviation between the calculated andexperimentally determined iodine value and epoxy oxygencontent . Marquardt method was successfully used to fitthe experimental data. A fourth-ordered Runge-Kuttamethod was applied for integrating the system ofdifferential equations of the model.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013, Ham bitkisel yağlardan, gıda veya endüstriyel amaçlı kullanıma uygun yağ elde etmek üzere yağın oksidasyon direncini, tadını ve kokusunu bozarak tüketiminde sorun yaratan serbest yağ asitlerinin (SYA) giderilmesi, rafine yağ kalitesi ve fiyatına en fazla etkiyi yapan adım olarak büyük önem taşır. Asit giderme işlemi için sıvı-sıvı ekstraksiyonuna dayanan prosesler, endüstride uygulanmakta olan kimyasal (alkali nötralizasyonu) ve fiziksel (distilasyon) yöntemlere alternatif olarak geliştirilen diğer yöntemlere göre öne çıkmaktadır. Ortam sıcaklığında ve atmosfer basıncında uygulanması nedeniyle daha az enerji tüketen “ılımlı” bir ayırma yöntemi olması ve atık probleminin olmaması, sıvı-sıvı ekstraksiyonunun en önemli avantajlarını oluşturmaktadır. Sıvı-sıvı ekstraksiyonuna dayanan alternatif proseslerin endüstriyel ölçekte geliştirilmesi için bitkisel yağ+yağ asidi+çözücü sistemlerine ilişkin sıvı-sıvı faz denge verileri temel oluşturmaktadır. Ancak, bu konuda literatürde yer alan veriler son yıllarda gerçekleştirilen sınırlı sayıdaki çalışmalara dayanmaktadır. Konuyla ilgili verilerin azlığı; ayrıca, bu verilerin genellikle rafine yağ+saf yağ asidi+çözücüden oluşan model karışımlarla elde edilmiş olması nedeniyle konu hala araştırmaya açık bir alan olarak önem taşımaktadır. Rafine yağ+saf yağ asidi+çözücüden oluşan model sistemler, yağların doğal hidrolizi sonucunda SYA ile birlikte oluşan kısmi gliseridleri içermezler. Hidrolizlenmiş yağlarda doğal olarak bulunan kısmi gliseridlerin, sıvı-sıvı ekstraksiyon için önemli olan faz dengeleri üzerine etkisi olabileceği öngörüldüğünden, bu çalışmada bu etkinin incelenmesi amaçlanmıştır. Bu amaçla gerçekleştirilen deneysel çalışmada, sıvı-sıvı faz dengelerinin belirlenmesi için kullanılan yağ-yağ asidi-çözücü sistemleri, asit değeri doğal olarak hidrolizle değişen, dolayısıyla içerdiği SYA yanında hidroliz reaksiyonu ile oluşan farklı miktarlarda kısmi gliseridleri de içeren bir yağ kullanılarak hazırlanmıştır. % 82 etanol içeren sulu etanol veya mutlak saflıkta metanol olmak üzere iki farklı çözücü için farklı sürelerde hidroliz sonucunda SYA ve kısmi gliserid içeriği değiştirilen çörek otundan elde edilen yağ (çözücü/yağ oranı 2:1) kullanılarak hazırlanan ÇOY+SYA+%82EtOH ve ÇOY+SYA+MeOH karışımları, 25ºC veya 30ºC’de çalkalamalı bir su banyosunda 24 saat bekletilmesi ile dengeye ulaşması sağlanmış; karışımın santrifüjlenmesi ile ayrılan rafinat ve ekstrakt fazlarının SYA, çözücü ve nötr yağ içerikleri ile bu çalışmada etkisi incelenen kısmi gliseridlerin ham yağ, rafinat ve ekstrakt fazlardaki içerikleri belirlenmiştir. Elde edilen iki sıvı-sıvı faz diyagramının benzer koşullarda (sıcaklık, çözücü cinsi) saf sistemler için elde edilmiş literatür verileriyle kıyaslanmıştır. Ayrıca, kısmen asitliği giderilmiş ve doğal olarak kısmi gliserid içeriği düşürülmüş çörek otu yağı kullanılarak yağ+saf yağ asidi+çözücü sistemi hazırlanarak kısmi gliserid etkisinin sıvı-sıvı faz dengelerinde belirgin olarak görüldüğü yüksek asitlik bölgesi için kıyaslama yapılmıştır. Bu kıyaslamalar sonucunda elde edilen bulgulara göre: • KG’lerin ÇOY+SYA+çözücü sistemi sıvı-sıvı faz dengeleri üzerinde dikkate değer bir etkisi bulunmaktadır. • Yağda SYA oluşumunun sonucunda doğal olarak meydana gelen polar yapılı KG’lerin ikili heterojen faz bölgesini biraz daralttığı belirlenmiştir. Bu etki özellikle KG derişiminin de yüksek olduğu yüksek SYA içerikli bileşimlerde (faz diyagramı üst bölgesi) belirginleşmektedir. • KG’lerin varlığı, her iki çözücü sisteminde de bağlantı doğrularının eğimini rafine yağ + saf yağ asidi + çözücüden oluşan model karışımlarda elde edilen bağlantı doğrularına kıyasla belirgin şekilde değiştirmektedir. Bu değişimin sonucu olarak SYA’lerinin dağılım katsayısı KG’lerin varlığında düşmektedir. Bu durum çözücülerin SYA ekstraksiyon kapasitesini düşürmektedir ve özellikle yüksek asitli yağlardan sıvı-sıvı ekstraksiyonuna dayanan asit giderme proseslerinin tasarımında dikkate alınması gereklidir. • Kullanılan çözücülerin polaritelerinin hemen hemen aynı olması nedeniyle, hem ÇOY+SYA+%82EtOH hem de ÇOY+SYA+MeOH sistemlerinde çözücülerin SYA seçicilikleri hemen hemen aynı olup, başlangıç yağındaki SYA derişiminin ve buna paralel olarak KG derişiminin artmasıyla azalmaktadır. • Çözücü ekstraksiyonu ile asit giderme yönteminin endüstriyel uygulamalarda kullanımı için sıvı-sıvı faz denge verileri üzerine daha çok çalışma yapılmasına ihtiyaç vardır. Bu çalışmalarda, ham yağdan kaynaklanan bütün önemli bileşenlerin etkisi göz önünde bulundurulmalıdır., The crude oil, extracted from oilseeds is a mixture of triglycerides, partial glycerids (mono- and diglycerides), free fatty acids (FFA), phosphatides, pigments, sterols and tocopherols. The complete steps of treatment to make the oil suitable for edible use is called refining and usually refers to the operations of pretreatment, deacidification, bleaching and deodorization. Crude oils consist of varying quantity of FFA along with triglycerides and increase of that has negative effects on the oxidation rancidity, flavor and odor of edible oil. FFA can be formed, however, by enzyme (lipase) action, after the oilseeds harvested. Hydrolysis of ester bonds in oils resulting in the liberation of FFA, may be caused by enzym action or by heat and moisture. In oils industry, the removal of free fatty acids (deacidification) of oils is important not only for the consumer acceptance but also because it has the maximum economic impact on production. Industrially the two most commonly used methods for refining are chemical (alkali neutralization) and physical (distillation) deacidification. However, for oils with high acidity, chemical refining causes high loses of neutral oil due to saponification and emulsification. The physical method is also a feasible process for deacidification of high acid oils. For deacidification of high acid oils this method has several advantages over traditional alkali deacidification such as reduced oil losses, simplified operation, less steam, water and power consumption, and reduced generation of environmental pollutants. However, it has also some inconveniences such as very stringent pretreatment requirements and unsuitable for heat sensitive oils. The basic unit operations in vegetable oil processing have remained relatively unchanged for 6-7 decades. Because of the several drawbacks to today’s technology, alternative approaches are needed to overcome these drawbacks. New approaches for deacidification of vegetable oils have been proposed in literature, such as biological deacidification, chemical reesterification, supercritical fluid extraction, membrane processing and solvent (liquid-liquid) extraction. Liquid-liquid extraction, which is based on the differences in the solubility of FFA and triglycerides in a organic solvent, has been receiving attention due to its advantages in comparison to conventional and the other alternative processes. It can be carried out under mild conditions (at room temperature and atmospheric pressure), thereby reducing the energy consumption. Besides, liquid-liquid extraction has the advantages of avoiding the formation of waste products and reducing the loss of neutral oil. Furthermore, solvent stripping from deacidified oil and solvent recovery from extract stream can be easily performed by evaporation at relatively low temperatures. For industrial adoption of liquid-liquid extraction as a deacidification method, it is necessary to generate liquid-liquid equilibrium data of the vegetable oil + free fatty acid + solvent systems. However, the data existing in the related literature is limited to just a few studies conducted only in the recent years. Furthermore, most of these data has been obtained by using model systems, which consist of refined oil + fatty acid + solvent . The model systems consisting of refined oil + pure fatty acid + solvent exclude partial glycerides as a result of hydrolyze reaction of neutral oils with the product of FFA. Because of the prediction of the partial glycerides in the hydrolised crude oil could affect the phase equilibrium important for the liquid-liquid extraction; the purpose of the present study is the investigation of this effect. As a result of hydrolyze reaction, raw vegetable oils contains partial glycerides in addition to FFAs. On the other hand, these compounds are not exist in the model systems prepared by using the refined vegatable oils. These compounds may have an important effect on the liquid-liquid phase diagram. The presence of partial glycerides may change the distribution of FFAs between the phases. Therefore, the aim of the present study is to investigate the effect of partial glycerides on the liquid-liquid equilibrium data of the vegetable oil + free fatty acid + solvent systems. For this aim, black cumin (Nigella Sativa L.) seed oil (BCS oil) was selected for preparing the vegetable oil + free fatty acid + solvent system. The reason for this choice is the increase in FFA and partial glyceride content of the oil in ground black cumin (Nigella Sativa L.) seeds by rapid hydrolysis reaction as a result of high lipase activity. In the dormant seeds lipase enzymes are generally inactive, but when the seeds are ground to obtain the oil, the lipase and oil come into direct contact and enzymatic hydrolysis reactions commence immediately. Since the black cumin (Nigella Sativa L.) seed oil contains both FFAs and partial glycerides, unlike the model systems, vegetable oil + free fatty acid + solvent systems were prepared by mixing the oil with the selected solvents without extra addition of FFAs. Aqueous ethanol (82% EtOH) and anhydrous methanol (MeOH) were selected as solvents. In the edible oil processing ethanol is considered as an appropriate solvent because it has low toxicity, easy recovery in the process, good values of selectivity and distribution for FFAs. Moreover, with EtOH, the loss of neutracetical compounds during liquid-liquid extraction is relatively low. Although FFA distribution coefficient decreases slightly by adding water to the ethanol, because of large increase in the heterogeneous region and in the selectivity in the presence of water, aqueous ethanol (82% EtOH) was preferred. MeOH is already used as reactant in the production of biodiesel. Therefore, it is appropriate for deacidification of high acidity vegetable oils by liquid-liquid extraction for using as raw material in biodiesel production. Based on the rapid hydrolysis of oil in the ground black cumin (Nigella Sativa L.) seed, in order obtain oils with varying FFAs and partial glyceride contents ground seeds were hold at ambient conditions for varying periods of time. The oil was obtained either by solvent extraction or by cold pressing of the seeds. For the determination of liquid-liquid equilibrium data, BCS oil were mixed with the selected solvents in the volume ratio solvent/oil 2:1. Then, the mixtures were hold in a thermostatic shaker (Julabo SW23) at a selected temperature for 24 hours. The shaking frequency was adjusted to 150 rpm in all experiments. After this treatment, the mixtures were centrifuged for 1 h at 3500 rpm and the clear phases were separated. For determining the composition of both phases the concentration of FFAs was determined by titration with an automatic buret. The total solvent concentration was determined by evaporation in a rotary evaporator. Having determined the concentration of FFAs and the solvent, the concentration of triglycerides was obtained by difference. The content of partial glycerides in the BCS oils and in the raffinate phases was determined by classical column chromatography. As stationary phase silica gel was used. The predicted effects of partial glycerides on the liquid-liquid equilibrium data were examined by comparing the experimental data obtained in this study with the data taken from the literature. For this comparison the data taken from the literature was selected among the data obtained under the same equilibrium conditions (temperature, type of solvent) but by using model systems, namely refined oil+FFA+solvent. The liquid-liquid equilibrium data of “BCS oil +FFAs+82% EtOH” system was compared with the data of “Refined Grapeseed Oil+Linoleic Acid+82% EtOH”. The liquid-liquid equilibrium data of “BCS oil +FFAs+ MeOH” system was compared with the data of “Corn Oil+Oleic Acid+MeOH”. In order to verify the conclussions obtained from the comparisons, additional equilibrium experiments with one selected initial acidity of BCS oil were performed for each system (“BCS oil +FFAs+82% EtOH” and “BCS oil +FFAs+ MeOH”). For these experiments the BCS oil was partially deacidified by ethanol extraction.After this treatment the acidity of the partially deacidified BCS oil was readjusted to a selected value. Because the differences between the equilibrium data of model systems and the systems investigated in this study are more pronounced on the high acidty region of the phase diagrams, these reference experiments were performed with BCS oil containing FFAs of about 31%. As a result of this study, it was concluded that: • the partial glycerides have considerable impact on the liquid-liquid equilibrium data of BCS oil +FFAs+Solvent system. • the presence of partial glycerides in raw vegetable oils slightly increases binary heterogeneous phase region. This effect is more noticable on the high acidity region of the phase diagrams. • both in “BCS oil +FFAs+82% EtOH” system and “BCS oil +FFAs+ MeOH” system the more remarkable effect of partial glycerides on the liquid-liquid equlibrium is the change of the slopes of tie lines. This change is also more noticable on the high acidity region of the phase diagrams. This effect is to decrease the distribution coefficient of FFAs. Therefore, decreasing capacity of solvent for extracting FFAs should be considered in the design of liquid-liquid extraction processes for deacidification of high acidity vegetable oils. • the selectivity of 82% EtOH and anhydrous MeOH for FFAs is almost same because of their similar polarities. The selectivity of both solvents decreases with increasing partial glyceride content of the oil. • industrial scale applications of solvent extraction as deacidification process require further investigations on the related liquid-liquid equilibrium data and models., Yüksek Lisans, M.Sc.

The non-random, two-liquid (NRTL) model with three different forms of temperature dependant parameters was used to correlate the liquid­liquid equilibrium data for systems of alcohols with alkanes, and alcohols with two ionic liquids: 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([bmmim][BF4]) and 1-butyl-3-ethylimidazolium tetrafluoroborate ([beim][BF4]). Different temperature dependences of the NRTL parameters were tested on thirteen literature experimental liquid-liquid equilibrium data for binary systems. NRTL model sa tri različita temperaturno zavisna parametra korišćen je za korelisanje ravnoteže tečno-tečno za binarne sisteme alkohola sa alkanima, kao i alkohola sa dve jonske tečnosti: 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([bmmim] [BF4]) i 1-butyl-3-ethylimidazolium tetrafluoroborate ([beim][BF4]). U radu su testirane tri različite forme temperaturne zavisnosti parametara NRTL modela. Ravnoteža tečnost-tečnost je modelovana na trinaest binarnih sistema. Kod svih sistema su dobijeni veoma zadovoljavajući rezultati sa srednjim greškama oko 3 %, korišćenjem sve tri forme temperaturne zavisnosti.

Enzymatic alcoholysis of fish oil can produce monoacylglycerols rich in polyunsaturated fatty acids at atmospheric pressure and low temperature. Biocatalysis in organic solvents helps to create a homogeneous reaction system for the reactants, ethanol and fish oil. This work presents liquid–liquid equilibrium at two different temperatures (303.2 K and 323.2 K) and at atmospheric pressure for two solvent-systems in the ethanolysis of fish oil: ethanol + oil + tert-pentanol and ethanol + oil + hexane. Experimental solubility (binodal) curves were obtained by the cloud point method and tie-line composition was obtained by density and high-temperature gas chromatography. The consistency of experimental tie-line data was checked by using the Othmer–Tobias equation. The experimental liquid–liquid data were correlated satisfactorily by the nonrandom two liquid model for activity coefficient calculations., MINECO (CTQ2012-39131-C02-01) and CDTI (ref. IDI-20111225)

International audience; The present work focuses on the thermodynamic modeling of the Bunsen section of the Iodine-Sulfur thermochemical cycle for hydrogen production on the basis of a combination of UNIQUAC activity coefficient and solvation models. The complexity of the material system, two immiscible electrolyte aqueous phases (H$_2$SO$_4$ rich and HI$_x$ rich), is managed by defining an equivalent material system able to capture the main physical phenomena. Only the key species involved and their mutual interactions are taken into account, reducing the number of parameters to be estimated from a hundred to only 15. Results show a good agreement with published experimental data, with a better description of the impurities in the HIx phase than in the sulfuric acid phase.

The lowest temperature at which water-KC1-2-propanol mixtures cannot be split has been determined as 25.3°C. Seven diagrams of liquid-liquid-solid equilibria for the ternary system water-potassium chloride-2-propanol around this temperature have been measured and the transition between their two different shapes has been studied. The authors wish to thank the DGICYT (Spain) for the financial aids of Project PB93-0946.

The determination region of solubility of methanol with gasoline of high aromatic content was investigated experimentally at temperature of 288.2 K. A type 1 liquid-liquid phase diagram was obtained for this ternary system. These results were correlated simultaneously by the UNIQUAC model. The values of the interaction parameters between each pair of components in the system were obtained for the UNIQUAC model using the experimental result. The root mean square deviation (RMSD) between the observed and calculated mole percents was 3.57 % for methylcyclohexane + methanol + ethylbenzene. The mutual solubility of methylcyclohexane and ethylbenzene was also investigated by the addition of methanol at 288.2 K.

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Liquid-Liquid equilibrium data were obtained for the polyethylene glycol2000(PEG2000)-sodium citrate-water system at 298.15, 308.15 and 318.15 K. The effect of temperature on binodal and tie line data was studied and published in a previous article (Murugesan and Perumalsamy, 2005). The interaction parameters of ASOG and UNIFAC models were estimated using the LLE data of PEG2000-sodium citrate-water system and are used to predict the LLE data for PEG6000-sodium citrate-water system at 298.15, 308.15 and 318.15 K (literature data). The predicted LLE data by both ASOG and UNIFAC models showed good agreement with the experimental and literature data.

(Liquid + liquid) equilibrium (LLE) data for (water + propionic acid + solvent) were measured at T= 298.2 K and atmospheric pressure. The solvents were methyl isoamyl ketone (5-methyl-2-hexanone) and diisobutyl ketone. The tie-line data were predicted by the UNIFAC method. A comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients separation factors and solvent free selectivity bases.