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This work reports the production of mono- and diglycerides from olive oil in pressurized n-butane as solvent medium. For this purpose, a commercial immobilized lipase (Novozym 435) was employed as a catalyst and sodium (bis-2-ethyl-hexyl) sulfosuccinate (Aerosol-OT or AOT) as a surfactant. The experiments were conducted in the batch mode varying the glycerol-to-oil molar ratio, n-butane-to-substrate mass ratio, enzyme concentration, temperature, pressure, and AOT concentration. Results showed that lipase-catalyzed glycerolysis in compressed n-butane might be a potential alternative route to conventional methods, as high contents of reaction products, especially monoglycerides (∼70 wt%), were achieved at mild temperature and pressure with a relatively low solvent-to-substrate mass ratio (4:1) in short reaction times (2 h).

The aim of this work is to report phase equilibrium data for the binary systems (CO2 + α-humulene) and (CO2 + trans-caryophyllene), and for the ternary system (CO2 + α-humulene + trans-caryophyllene). Results from literature show that α-humulene and trans-caryophyllene are the main compounds responsible for the anti-inflammatory and anti-allergic characteristics attributed to the medicinal plant Cordia verbenacea D.C., hence giving importance to the phase behaviour investigation performed in this work. Phase equilibrium experiments were performed in a high-pressure, variable-volume view cell over the temperature range of T = (303 to 343) K and pressures up to 20 MPa. (Liquid + liquid) and (vapour + liquid + liquid) equilibrium were observed at T = 303 K, while (vapour + liquid) phase transitions were verified to occur from T = (313 to 343) K, for all systems studied. Thermodynamic modelling was performed using the Peng–Robinson equation of state and the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.

The objective of this work was to investigate the application of the solution enhanced dispersion by supercritical fluids (SEDS) technique for the precipitation of pure β-carotene and copolymer poly(3-hydroxybutirate- co -hydroxyvalerate) (PHBV), as well as some encapsulation tests of the solute in the biopolymer. The following parameters were investigated in the precipitation of pure β-carotene: pressure (8.0 and 12.0 MPa), anti-solvent flow rate (20–40 mL/min) and concentration of β-carotene in an organic dichloromethane solution (4 and 8 mg/mL). For pure β-carotene, the results showed that the mean particle size varied from 3.8 to 246.8 μm, depending on the processing conditions. The morphology of β-carotene was modified from plate-like to leaf-like particles, as verified by micrographs of scanning electronic microscopy (SEM). For the PHBV precipitation, the SEM micrographs showed that for all experimental conditions the morphology of polymer was different from the unprocessed material. The precipitated polymer presented a quasi-spherical shape with interconnected particles in the sub-micrometric range (particle size in the range of 278–570 nm), while the unprocessed material was composed of films and large blocks. The co-precipitation tests showed that the best ratio of β-carotene to PHBV in solution was 1:3 (w/w), which resulted in approximately 80% of encapsulation. Fluid phase behavior of the ternary systems CO 2 + dichloromethane + β-carotene and CO 2 + dichloromethane + PHBV was also investigated with the aim of elucidating the region of the phase diagram in which the precipitation occurs. Phase equilibrium data were measured in the temperature range of 303–343 K, with CO 2 compositions ranging from 40 to 90 wt% for β-carotene, and from 30 to 90 wt% for PHBV. Vapor–liquid and also solid–vapor–liquid phase transitions were observed in the phase equilibrium study. It was observed that the presence of β-carotene or PHBV in the ternary mixture had a little influence on the fluid phase behavior of the systems.

This work investigates the phase equilibrium behavior of the constituents involved in the reaction medium of cyclohexane oxidation to produce cyclohexanol and cyclohexanone in compressed carbon dioxide. For this purpose, high-pressure cloud point data for binary, ternary, and quaternary CO2-containing systems with the reactant (cyclohexane) and the main products (cyclohexanol and cyclohexanone) were measured. The static synthetic method using a variable-volume view cell was employed for obtaining the experimental data in the temperature range of (293 to 343) K at several overall compositions and pressures up to 27 MPa. The experimental data were satisfactorily represented by the Peng−Robinson equation of state (PR-EoS) with the classical quadratic mixing rules.

Microparticles of theophylline were recrystallized using the high-pressure antisolvent technique. A mixture of ethanol and dichloromethane with a volumetric ratio of 1:1 was used as solvents, and compressed CO 2 as antisolvent. The effects of process parameters (temperature, flow rate of solution and antisolvent, drying rate, initial solution concentration, diameter and length of the capillary expansion tube, and pressure gradient between the organic solution feed and the precipitation chamber) on particle size, size distribution and morphology were evaluated through an experimental design technique. In order to help selecting the appropriate operating conditions and understand the precipitation mechanism, the fluid phase behavior of ternary (CO 2 -solvents) and quaternary (CO 2 -solvents–theophylline) systems were investigated using a static synthetic method. Plate-like particles were produced in all experimental conditions with length ranging from 3 to 70 μm. Also, slightly agglomerated particles were produced in some experiments, while in others a quite pronounced agglomeration was observed. Phase diagram of the mixture revealed that the contact mechanism between solution and antisolvent occurred in two different ways, influencing the aggregation, particle size and particle size distribution. The X-ray powder diffraction patterns (XRD) showed a change in theophylline crystallinity. This fact was confirmed by differential scanning calorimetry (DSC) analysis. Also, infrared spectroscopy analysis (FTIR) showed that the recrystallized powder presented a degree of purity higher than that of unprocessed theophylline. Thermal gravimetric analysis (TGA) indicated that the lower mass loss temperature values were found for small size particles and particles with crystalline structure.

This work reports experimental phase equilibrium (transition points) data for the systems CO2 + ethyl acetate, CO2 + ethyl acetate + β-carotene, and CO2 + ethanol + β-carotene at different concentrations of β-carotene in the organic (liquid) solvents. For this purpose, the static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data in the temperature range from (303 to 343) K and pressures up to 12 MPa. Vapor−liquid phase transitions were observed as bubble and dew points for all overall compositions investigated. In a general sense, it was experimentally observed that the addition of β-carotene leads to negligible changes in pressure transition values compared to CO2 + solvent systems. The Peng−Robinson equation of state, with the classical van der Waals quadratic mixing rule, was employed for the thermodynamic modeling of the systems investigated with a satisfactory agreement between experiment and theory. It was also observed that the interaction paramet...

In this work, the mutual solubilities of sets of ionic liquids ([CnMIM] [TF2N] (n = 4, 8, 12), [C4PY] [TF2N], [C8MIM] [OTF]) and organic compounds (heptane, o-xylene, toluene, or water) are investigated. The experimental data measured for these systems were used to adjust the binary interaction parameters between their components for the Non-Random Two Liquid (NRTL) model. The results showed that the solubility increased with temperature, with high hygroscopicity (10-1 in terms of mole fraction) of the ILs, low interactions with aliphatic hydrocarbons, high interactions with aromatic hydrocarbons and the presence of a lower critical solution temperature (LCST). In addition, this study is the first to show that [C12MIM] [TF2N] is completely soluble in toluene and ortho-xylene between 273.15 and 373.15 K at 1 bar. The average deviations related to the mole fraction between the experimental and calculated values by the NRTL were less than 2.4%.

Water-in-oil (W/O) emulsions are complex mixtures generally found in crude oil production in reservoirs and processing equipment. Sedimentation studies of water-oil emulsions enable the analysis of the fluid dynamic behavior concerning separation of this system composed of two immiscible liquids. Gravitational settling was evaluated in this article for a model emulsion system consisting of water and a Brazilian crude oil diluted in a clear mineral oil as organic phase. The effects of water content and temperature were considered in the study of sedimentation velocity of water-oil emulsions. Water contents between 10% and 50 % and temperatures of 25, 40 and 60 ºC were evaluated, and a Richardson-Zaki type correlation was obtained to calculate settling velocities as a function of the process variables investigated. Water contents and average droplet sizes were monitored at different levels in the settling equipment, thus enabling identification of the effect of these variables on the phenomena of sedimentation and coalescence of the emulsions studied. The results showed that the emulsion stability during sedimentation was governed by the emulsion water content, which yielded high settling velocities at low water contents, even when very small droplets were present. A quantitative analysis of the combined effects of drop size and droplet concentration supports the conclusion that a stronger effect is produced by the higher concentration of particles, compared with the relatively smaller effect of increasing the size of the droplets.

Enhanced oil recovery (EOR) processes are important to the petroleum industry. In the EOR, gases such carbon dioxide (CO2) and natural gas are injected in the petroleum reservoirs for oil recovering. It is well known that the interfacial tension between the injected gas and the oil has influence on the efficiency of displacement of oil by gas. When the injected gas becomes miscible with the oil, it is displaced with efficiency, resulting in high recoveries. In this study, an experimental setup is established to measure the dynamic and equilibrium interfacial tensions (IFT) of the Brazilian crude oil + CO2 system under various conditions using the pendant drop technique. This experimental technique is used to determine the interfacial tension of the above system at different pressures and temperatures. The measured IFT data will provide a better understanding of the interfacial interactions between the crude oil and CO2 and, consequently, to improve the economics of the gas injection process.

RESUMO – O uso de liquidos ionicos e irradiacao micro-ondas como desemulsificante de emulsoes de petroleo tipo agua/oleo representa um novo campo de estudo. O principal objetivo deste trabalho e investigar o efeito do par liquido ionico/etanol no processo de desemulsificacao de emulsoes de petroleo pesado via micro-ondas. Os resultados indicam a selecao de um solvente adequado pode facilitar a mistura do liquido ionico no petroleo bruto, produzindo melhores resultados de desemulsificacao em menores concentracoes.

This work investigated the high-pressure phase behavior of systems containing glycerol, olive oil and propane in the presence of surfactant AOT. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data in the temperature range from 298 to 373 K, and pressures up to 30 MPa. First, the effect of addition of AOT on the vapor pressure of pure propane was investigated and then the effect of addition of AOT to mixtures of propane + glycerol. Measurements were afterwards accomplished for the system propane + AOT + glycerol + olive oil. For the ternary system liquid–liquid (LLE) and vapor–liquid–liquid (VLLE) equilibrium were observed. Besides VLE, LLE and VLLE, the quaternary system propane + AOT + glycerol + olive oil exhibited at higher concentrations of the glycerol/olive oil ratio a fascinating phase behavior, with the occurrence of three (LLL) and four (VLLL)—phases in equilibrium.

This work provides experimental phase equilibrium data of binary and ternary systems involving carbon dioxide (CO 2 ), ethanol, soybean oil, castor oil and their fatty acid ethyl esters. Here the oils and their fatty acid ethyl esters were treated as pseudo components. The experiments were carried out in a high-pressure variable-volume view cell in the temperature range of 13–70 °C, for carbon dioxide overall composition ranging from 5 to 45 wt.% and pressures up to 270 bar. The Peng–Robinson and statistical associating fluid theory (SAFT) equations of state were used to represent the experimental data, and results show that for fatty acid esters both models provide satisfactory representation of experimental data, while for the vegetable oils the SAFT demonstrated superior performance compared to the Peng–Robinson equations of state (EoS).

This work reports experimental phase equilibrium data of binary and ternary systems involving carbon dioxide, propane, and glycidyl methacrylate (GMA). Phase equilibrium experimental data were obtained according to the static synthetic method using a variable volume view cell. The experiments covered the temperature range of (303 to 343) K, pressures up to 13 MPa, at several overall compositions. The experimental data were modeled with the Peng−Robinson equation of state (PR-EoS) with the conventional quadratic mixing rules. The EoS interaction parameters were fitted from binary systems and then used to predict the phase behavior of the ternary system. The results showed that, in the experimental range investigated, only vapor−liquid transitions were found and that the PR-EoS was capable of satisfactorily representing the experimental data.

The main objective of this work was to investigate the high-pressure phase behavior of the binary systems CO 2 –lemon ( Citrus latifolia Tanaka) and CO 2 –bergamot ( Citrus bergamia Risso et Poit.) peel oils. The static synthetic method using a variable-volume view cell was employed for obtaining the experimental data in the CO 2 overall composition range of 5–98 wt.%, from 313 to 343 K and pressures up to 19 MPa. For both systems, the experimental data revealed the occurrence of vapor–liquid, liquid–liquid and vapor–liquid–liquid phase transitions. Additionally, vapor–liquid equilibrium data were measured for CO 2 –linalyl acetate, one of the major compounds of the bergamot oil. The thermodynamic modeling was performed using the Peng–Robinson equation of state with the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.

trategies have been successfully developed for the monitoring of the homo and copolymerization of styrene and butyl acrylate in a miniemulsion system using near-infrared (NIR) spectroscopy. Different concentrations of costabilizer, stearyl methacrylate, are tested to obtain the best stabilization condition. The spectral data are associated with the properties of the reaction medium, such as particle average diameter, conversion, number, and surface area of particles, through linear regression based on partial least squares. It is observed that the NIR spectrophotometer is sensitive to the dynamics of miniemulsion polymerization reactions, thus confirming the promising aspect of NIR technology for monitoring the latex properties.

Aerogel and xerogel are formed via hydrolysis and polycondensation reactions of silica precursors, such as tetraethylorthosilicate (TEOS), always careful not to cause collapse, reduction in surface area and pore size. Several studies shown the use sol-gel entrapment possesses a number of desirable attributes, as the enzyme is physically entrapped in a rigid glass framework that permitted stabilization of the enzymes, terciary structure owing to the tight gel network. In this study, have focused on the screening of immobilization method in aerogel matrix in the presence of protic ionic liquid (PIL) with evaluation catalytic efficiency and operational stability. The novel mesoporous silica supports (aerogels) obtained by the sol-gel technique was used to immobilize commercial Burkholderia cepacia (BC) lipase by physical adsorption, covalent binding and encapsulation in the absence and presence de protic ionic liquid (N-methylmonoethanolamine pentanoate - C5). Catalytic efficiency was determined in the analyses of hydrolytic activities were carried out on the lipase loading solution and immobilized enzyme to determine the total activity recovery yield, Ya (%). For physical adsorption the recovery of activity with PIL was 82.95% (ADSLI) and in the absence 70.31% (ADS). Operational stability of the enzyme has also been examined and obtained similar values a half-life of 0.73 h to ADSLI and 0.88 h for ADS occurs with 2 batches. And other immobilized technique, covalent binding the results showed that in aerogels supports in the presence of C5 obtained 69.13% (CBLI) of total activity recovery yield and 39.11% (CB). Under such conditions, the operational stability tests indicated that a small enzyme deactivation occurs after 15 batches, revealing a biocatalyst half-life of 7.5 h for CBLI. For encapsulation, the recovery of activity with PIL (ENLI) was 45% and 37% in the absence PIL (EN). ENLI exhibited a half life of more than 23 batches with 70% of its activity remaining, with around 11.5 h. And EN the half-life was 6.5 hours, totaling 13 batches. Therefore, ADSLI presented good efficiency with total activity recovery yield but for operational stability ENLI showed the best between immobilization methods studied. Hence, it is rather appropriate for application in hydrolytic processes.

Candida rugosa lipase (CRL) was immobilized on an eco-friendly support poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV), by physical adsorption, using different ionic liquids (ILs) as immobilization additives. This was to investigate the influence of cationic core ([C4mpy]Cl, [C4min]Cl), of anions ([C4min]Cl, [C4min]N(CN)2, [C4min]Tf2N), and of cation chain length ([C2min]Tf2N, [C4min]Tf2N) in the immobilization process. The immobilized biocatalysts (IB) were characterized with respect to the morphological, physico-chemical properties, total activity recovery yield (Ya), and biochemical properties of more efficient IB were evaluated. Initially, it was found that the change of cationic core did not influence in Ya compared to the control. With change of anions, it was seen that the best result was obtained for the more hydrophobic anion (Tf2N), and finally increasing the cation chain length increased Ya. IB most efficient with [C4min]Tf2N obtained 78 % of Ya, more than twice the control value (30 %) and a considerable enhancement of operational stability compared with the control.

This work is aimed to investigate the extraction of palm oil using pressurized ethanol and propane as solvents. The effects of temperature (293⿿333 K), pressure (from 10 to 20 MPa), solvent flow rate (from 1 to 5 mL/min), and composition of the solvent mixture were evaluated on the oil extraction yield, and chemical profile of the extracted oils. The experiments were conducted in a 100 mL extractor coupled to a HPLC pump for ethanol and a syringe pump for the propane displacement. Global yields up to 75 wt% were obtained in the experiments. The kinetic profiles of the extractions were described by the Sovova⿿s model, which presented good agreement with the experimental observations. The palm oils extracted with distinct solvents were characterized regarding its density and viscosity in a temperature range from 293 to 343 K, its chemical profile determined by GC/MS, and carotenoid content.

In this work we investigated the phase equilibrium behavior of the binary asymmetric systems propane (C3) + n-eicosane (C20) and carbon dioxide (CO2) + n-eicosane (C20). We used a variable-volume view cell for obtaining fluid-fluid equilibrium (FFE), solid-fluid equilibrium (SFE) and solid-fluid-fluid equilibrium (SFFE) experimental data. We modeled the phase equilibria of both systems using the Peng-Robinson Equation of State for describing the fluid phases and an expression for the fugacity of pure solid n-eicosane with parameters fit to reproduce the pure n-eicosane melting line. We performed the phase equilibrium calculations by implementing path-following methods for tracking entire solid-fluid (SF) and solid-fluid-fluid (SFF) equilibrium curves for binary asymmetric mixtures. This made it possible to obtain complete isoplethic lines or complete three-phase equilibrium lines in single runs. Although the model is relatively simple, it is able to grasp the complex observed behavior for the systems studied here. © 2009 Elsevier B.V. All rights reserved. Fil: Rodriguez Reartes, Sabrina Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina Fil: Cismondi Duarte, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina Fil: Franceschi, E.. URI Erechim; Brasil Fil: Corazza, M. L.. URI Erechim; Brasil Fil: Oliveira, J. Vladimir. URI Erechim; Brasil Fil: Zabaloy, Marcelo Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

Empty fruit bunch fiber (EFBF) is a lignocellulosic waste generated by the palm oil agribusiness. The amount of EFBF produced is equal to the oil obtained, and it can be used as raw material to obtain biocomposites. The objective of this work is to fragment the EFBF employing pressurized fluids in a semi-continuous system to obtain different biocomposites. For this, pure water and a mixture of water/carbon dioxide were employed as solvent to obtain sugar monomers and a mixture of compressed water/ethanol (1:1 vol.) to obtain crystalline cellulose. The experiments were conducted in the temperature range of 120 to 240 ºC, using reaction times between 5 and 15 min at 60 bar, and solvent flow rate of 0.75 mL.min-1. A maximum of 30.47 mg.mL-1 of xylose was obtained at 210 ºC for 15 min of reaction with pure water as solvent. The best condition to obtain crystalline cellulose was 240 ºC for 30 minutes of reaction, obtaining 38.2% of cellulose from palm oil EFBF.

The main focus of the present work was to study the influence of the salinity of aqueous phase on the interfacial properties of a Brazilian crude oil/brine solutions. The pendant drop technique was used to conduct rheological dilatational studies, and a methodology for obtaining important parameters for the rheological study was also presented. The viscoelastic properties were evaluated through dynamic tests that were accomplished up to 24 h. The influence of the interfacial film aging time at 40 °C on the compressibility was also investigated. The results indicated that the values of the total interfacial elasticity and its components, viscous and elastic modulus, were enhanced with the increase of salt content of the brine solutions, suggesting that the salt induces the formation of a more rigid interfacial film. Also the presence of salt led to a stronger interfacial activity of the surfactants yielding higher interfacial elasticity and compressibility.

This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE), liquid-liquid (LLE) and vapor-liquid-liquid (VLLE) equilibrium were recorded. It was experimentally observed that, at a given temperature and surfactant content, an increase in the concentration of glycerol/oil ratio led to a pronounced increase in the slope of the liquid-liquid coexistence curve. A comparison with results reported for the same system but using propane as solvent showed that much lower pressure transition values are obtained when using n-butane.

Hancornia speciosahas bioactive molecules such as phenolic compounds which exhibit antioxidant and anti-microbial properties. Nevertheless, the separation of these substances from a medicinal plant can be differentaccording to the extraction process and solvent used. Thus, the present study aimed was to separate phenoliccompounds fromHancornia speciosaleaves in three steps by using a sequential pressurized liquid extraction andevaluated their antioxidant and antibacterial activity. Results showed that the temperature increase from 25 to60° C provides a significative enhancement in the extraction yield. The raw ethanol extract (39.0 ± 0.2%)showed the highest overall extraction yield. However, fractionated ethanol extract (FEE) at 60 °C exhibited thehighest amount of total phenolic compounds (347.0 ± 4.12 mg/g extract). Fractionated ethyl acetate extract(FAE) at 60 °C presented improved quantity of totalflavonoids (230.4 ± 3.5 mg/g extract) and rutin content(16.6 ± 0.3 mg/mL extract). The antioxidant activity results for IC50of DPPH indicated that FEE(3.8 ± 0.1 ?g/mL) was the best free radical scavenger. FAE and FEE were able to inhibit the growth of mul-tidrug-resistantE. coli. Made available in DSpace on 2020-01-14T18:12:36Z (GMT). No. of bitstreams: 1 1s2.0S138358661930334Xmain.pdf: 429605 bytes, checksum: 20ef950a051821a5194a4f8d0e0b85df (MD5) Previous issue date: 2019

Orientador: Prof. Dr. Lúcio Cardozo-Filho Coorientador: Prof. Dr. Dirceu Noriler ; Prof. Dr. Henry França Meier Tese (doutorado em Engenharia Química)--Universidade Estadual de Maringá, Centro de Tecnologia, Dep. de Engenharia Química, 2014 Resumo: O emprego de técnicas de micronização baseadas nas propriedades de fluidos supercríticos tem sido estudado e amplamente relatado na literatura. A principal vantagem da utilização dos fluidos supercríticos é que eles podem ser eficientemente separados, por descompressão, a partir de ambos os solventes orgânicos e produtos sólidos, facilitando um processo limpo e reciclável de uma grande variedade de produtos de alta qualidade da indústria farmacêutica e de alimentos O poder de solvatação do fluido supercrítico pode ser facilmente controlado ajustando-se a pressão e/ou temperatura, proporcionando novas oportunidades para a cristalização seletiva, separação de impurezas e controle de formas cristalinas. Do ponto de vista termodinâmico, as técnicas para a formação de partículas usando fluidos supercríticos mais facilmente empregadas são as do processo antissolvente supercrítico (SAS), pois o CO2 é usado como antissolvente, e uma solução de solvente orgânico mais o soluto sólido é expandida pela injeção do fluido sub ou supercrítico. O processo SAS explora tanto o poder elevado de fluidos supercríticos para dissolver solventes orgânicos, como a baixa solubilidade de compostos farmacêuticos em fluidos supercríticos, resultando normalmente na obtenção de partículas de pequenos tamanhos e de formatos esféricos, características desejáveis em muitas aplicações. Contudo, essa garantia só acontece se forem consideradas as condições de operação do processo, fatores importantes que facilitam o controle sobre o tamanho e distribuição do tamanho de partículas. Face a essas considerações e à dificuldade de encontrar um estudo sistêmico que relacione o comportamento fluidodinâmico da mistura supercrítica e os seus efeitos sobre o tamanho e distribuição do tamanho de partículas, propôs-se nesse estudo um modelo matemático capaz de prever os mecanismos de formação de micro e nanopartículas de substâncias químicas em processos do tipo SAS. O modelo resolvido numericamente levou em consideração os principais fenômenos físicos envolvidos no processo, incluindo a hidrodinâmica do jato, transferência de massa, bem como a nucleação e a cinética de crescimento da partícula, empregando-se um modelo de turbulência k-e tipo standard resolvido em conjunto com balanços de massa, momento e energia em duas e três dimensões e intercalado com as equações de balanço populacional (PBE). Os parâmetros cinéticos de precipitação das partículas do balanço populacional foram calculados a partir dos resultados experimentais da distribuição das partículas formadas. Os cálculos das propriedades, incluindo densidade, condutividade térmica, viscosidade e difusividade mássica, foram determinados via equação de estado de Peng-Robinson com regra de mistura quadrada de Van der Walls, Método de Chung e de Riazi e Whitson, respectivamente, empregando modelos para alta pressão. A resolução do modelo por fluidodinâmica computacional (CFD) permitiu discutir os efeitos no tamanho e distribuição de tamanho da partícula e mostrou boa concordância com os resultados experimentais, permitindo que a abordagem possa ser aplicada a sistemas semelhantes e contribua para melhorar o desempenho dos equipamentos de micronização que utilizam a técnica SAS, além de permitir prever as melhores condições de operação para a obtenção de menores partículas e de formatos esféricos Abstract: The use of spray drying techniques based on properties of supercritical fluids have been studied and widely reported in literature. The main advantage of the use of supercritical fluids is that they can be efficiently separated by decompression, from both organic solvents and solids, facilitating a clean recycling process of a wide variety of high quality products and the pharmaceuticaland food industry. The food solvating power of the supercritical fluid can be easily controlled by adjusting the temperature or pressure, providing new opportunities for selective crystallization, separation of impurities and control of crystal forms. From the viewpoint of thermodynamics, the techniques for particle formation using supercritical fluids more easily employed are those of the supercritical antisolvent method (SAS), as CO2 is used as the antisolvent and an organic solvent solution plus a solid solute is expanded by injection of a sub or supercritical fluid. The SAS process exploits both the high power supercritical fluid to dissolve organic solvents such as low solubility of pharmaceutical compounds in supercritical fluids, which ensures obtaining small size particles and of spherical shapes, desirable characteristics for many applications. However, this guarantee only happens if the operating conditions of the process are considered, important factors that facilitate control over the size and size distribution of particles. Given these considerations and the difficulty of finding a systemic study that relates the fluid dynamic behavior of supercritical mixture and its effects on the size, size distribution of particles in this study, a mathematical model able to predict the formation mechanisms micro, and nanoparticles chemical processes in the SAS type is proposed. The model solved numerically took into account the main physical phenomenon involved in the process, including the hydrodynamics of the jet, mass transfer, as well as the nucleation and growth kinetics of the particle, using the turbulence model of k-e standard type solved together with mass balance, momentum and energy in two and three dimensions and merged with the population balance equations (PBE). The kinetics parameters of particles precipitation of the population balance were calculated from the experimental results of the distribution of the particles formed. The calculations of the properties including density, thermal conductivity, viscosity and mass diffusivity were determined via equation of state of Peng-Robinson with a square mixture rule of Van der Waals and Chung method Riazi and Whitson, respectively, using models for high pressure. The resolution of the model by computational fluid dynamics (CFD) allowed the discussion of the effects on the size and size distribution of particle and showed good agreement with the experimental results, allowing the approach to be applied to similar systems and helping to improve the performance of the equipment that use the SAS micronization technique, as well as allowing to predict the best operating conditions for obtaining smaller particles and spherical shapes

Orientador: Prof. Dr. Lúcio Cardozo-Filho Coorientadora: Prof.ª Dr.ª Nádia Regina Camargo Fernandes-Machado. Coorientador: Prof. Dr. Marcos Lúcio Corazza. Tese (doutorado em Engenharia Química) - Universidade Estadual de Maringá, 2014. Este trabalho reporta novos dados experimentais da produção de H2 e redução de COT (carbono orgânico total) através da gaseificação da lactose (efluente sintético) e soro de leite (efluente real) em água supercrítica com ou sem a presença de catalisadores (NaOH, KOH e Na2CO3) ou oxidantes (H2OH e t-BHP) em um reator de fluxo continuo, construído em Inconel 625. Para o efluente sintético (lactose) foram realizadas reações em uma faixa de temperatura de 550 °C a 700 °C, pressão de 225 bar, concentrações de lactose na faixa de 5 g.L-1 a 25 g.L-1, fluxos de alimentação de 5 g.min-1 e 7 g.min-1 e tempo de reação de 30 minutos. A melhor condição de produção de H2 (700 °C e 5 g.L-1) apresentou rendimento de ˜ 4,5 (mol de H2/mol de lactose) e redução de COT de ˜ 95%. Contudo, a pior condição (550 °C e 25 g.L-1) apresentou rendimentos de ˜ 0,5 (mol de H2/mol de lactose) e redução de COT de ˜ 50%. Nessa condição operacional a utilização de catalisadores ou oxidantes elevou esses rendimentos de ˜ 0,5 até ˜ 5,0 (mol de H2/mol de lactose), como também aumentou a redução do COT para ˜ 97%. De maneira geral, o aumento da temperatura elevou as quantidades de H2 e diminui as quantidades de CO. Ou seja, a razão H2/CO se eleva com o aumento da temperatura e diminuição da concentração de lactose. Para as reações envolvendo soro de leite a gaseificação apresentou frações molares dos gases formados superiores aos dados obtidos para as reações com lactose. Os gases produzidos são majoritariamente o H2 e o CO2 e mínimas quantidades de CO e CH4. No entanto, o comportamento da produção desses gases é coerente para ambos os efluentes (real ou sintético). A vazão mássica dos gases produzidos representa 60-65% da vazão mássica de entrada do soro de leite. Sendo o restante constituído por coque formado no reator e pelo efluente tratado. A eficiência do tratamento do soro de leite, em relação a diminuição do carbono orgânico total (COT), passou de 5259 mg.L-1 para 421 mg.L-1, alcançando 85% de redução. Além das reações de gaseificação da lactose e soro de leite foram realizadas reações de oxidação de lixiviados (lixiviado), tendo como objetivo a degradação do mesmo. A aplicação da oxidação supercrítica em amostras de lixiviados apresentou satisfatória eficácia na redução dos parâmetros físico-químicos de DQO, COT, turbidez, cor e absorbância. A manipulação da vazão de alimentação (6 g.min-1 e 12 g.min-1), temperatura (550 °C, 600 °C, 650 °C e 700 °C) e pressão (150 bar e 225 bar) permitiram o obtenção de elevados níveis de degradação do efluente, alcançando valores próximos aos 100%. Como esperado, os níveis de redução dos parâmetros físico-químicos foram crescentemente alterados com a elevação da temperatura. Ou seja, quanto maior a temperatura, maior o nível de degradação. Entre as vazões estudadas não foram observadas significativas melhoras de performance, pois, as duas vazões apresentaram resultados semelhantes. Diferentemente da vazão, a pressão apresentou diferença nos resultados de redução da DQO, com uma diferença de aproximadamente 11% entre uma pressão e outra. Além da degradação do efluente, foi observada a formação de gases, principalmente o CO2. No entanto, a quantidade de gás produzido é insignificante quando comparado à produção de gás formada nas reações de gaseificação da lactose/soro de leite. De maneira geral, a gaseificação em água supercrítica de efluentes de laticínios e águas residuais (lixiviados) é uma alternativa eficiente para o aproveitamento energético, no sentido da produção de gases, principalmente o H2, e para o tratamento de efluentes. Desta forma, os resultados obtidos neste trabalho agregam informações de elevada importância para implantação de unidades de tratamento de efluentes e produção de hidrogênio a partir do emprego da gaseificação/oxidação em água supercrítica. A aplicação dessa tecnologia implica na solução de problemas das esferas energética e ambiental. Na esfera energética, essa a tecnologia apresenta impacto direto, produzindo energia a partir de biomassas. Na esfera ambiental, a tecnologia se propõe à destruição eficiente de resíduos industriais e águas residuais (lixiviados) que impactam sobre o custo social, ambiental e da saúde pública This work reports, new experimental data production of H2 and reduction of TOC (total organic carbon) from the gasification of lactose (synthetic wastewater) and whey (actual effluent) in supercritical water with or without the presence of catalysts (NaOH, KOH and Na2CO3) or oxidizing (H2OH and t-BHP) in a continuous flow reactor, built in Inconel 625. For the synthetic effluent (lactose) Reactions were carried out in a temperature range of 550 °C-700 °C, pressure 225 bar, lactose concentrations in the range of 5 g.L-1 - 25 g.L-1, feed streams of 5 g.min-1 and 7 g.min-1 and reaction time of 30 minutes. The optimum condition for the production of H2 (700 °C and 0.5%) had a yield of ˜ 4.5 (mol H2/mol lactose) and TOC reduction of ˜ 95%. However, the worst condition (550 °C and 25 g.L-1) had incomes of ˜ 0.5 (mol H2/mol lactose) and TOC reduction of ˜ 50%. In this operating condition the use of these catalysts or oxidizing increased yields of ˜ 0.5 to ˜ 5.0 (mol H2/mol lactose) as well as the reduction of TOC increased to ˜ 97%. In general, increasing the temperature increased quantities of H2 and CO decrease the amount. That is, the H2/CO ratio increases with increasing temperature and decrease in lactose concentration. For reactions involving whey gasification showed higher molar fractions of the data obtained for the reactions with lactose formed gases. The gases produced are mostly H2 and CO2 and trace amounts of CO and CH4. However, the behavior of the production of these gases is consistent for both effluents (real or synthetic). The mass flow rate of the produced gas is 60-65% of the mass flow rate of entry of whey. The remainder consisting of coke formed in the reactor and the treated effluent. The efficiency of treatment of whey, for lowering total organic carbon (TOC) decreased from 5259 mg.L-1 to 421 mg.L-1, reaching 85% reduction. In addition to the gasification reactions of lactose and whey oxidation of leachate (leachate) were performed, aiming to soil degradation. The application of supercritical oxidation of leachate samples showed satisfactory efficacy in reducing the physical and chemical parameters of COD, TOC, turbidity, color and absorbance. The manipulation of the feed flow (6 g.min-1 and 12 g.min-1), temperature (550 °C, 600 °C, 650 °C and 700 °C) and pressure (150 bar and 225 bar) allowed the achievement of high levels of degradation of the effluent reaching values close to 100%. As expected, the levels of reduction of physical-chemical parameters were increasingly altered with increasing temperature. That is, the higher the temperature, the higher the level of degradation. Among the flows studied no significant performance improvements were observed, as the two flow rates showed similar results. Unlike the flow, the pressure difference in the results presented for the reduction of COD, with a difference of approximately 11% between one and another pressure. In addition to the degradation of the effluent, the formation of gases, mainly CO2 was observed. However, the amount of gas produced is negligible when compared to the production of gas formed in the gasification reactions of lactose/milk whey. In general, in supercritical water gasification dairy effluent and waste water (leachate) is an efficient alternative to energy production, for the production of gases, particularly H2 and for effluent treatment. Thus, the results obtained in this study add information of relevance and importance to deploying units wastewater treatment and hydrogen production from the use of gasification/oxidation in supercritical water. The application of this technology involves the solution of problems in energy and environmental scope. Energy in scope, this technology has a direct impact, producing energy from biomass. Environmental scope, technology is proposed for the efficient destruction of industrial waste and wastewater (leachate) that impact on the environmental and social cost of public health