Programa de Pós-graduação em Engenharia Química
URI Permanente desta comunidade
Navegar
Navegando Programa de Pós-graduação em Engenharia Química por Data de Publicação
Agora exibindo 1 - 20 de 42
Resultados por página
Opções de Ordenação
Item Catalisadores heterogêneos para produção de chalconas: reação de condensação de Claisen-Schmidt(Universidade Federal de Goiás, 2016-03-07) Winter, Caroline; Pérez, Caridad Noda; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4792149E3; Alonso, Christian Gonçalves; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4777466U2; Alonso, Christian Gonçalves; Pérez, Caridad Noda; Machado, Nádia Regina Camargo Fernandes; Oliveira, Guilherme Roberto deThe members of flavonoids and chalcones family have attracted great interest because of their pharmacological applications as antibacterial, anti-inflammatory and anticarcinogenicagents, and are commonly synthesized by Claisen-Schmidt condensation between acetophenone and benzaldehyde derivatives. This reaction is usually catalyzed under homogeneous conditions which present, however, several drawbacks such as catalyst recovery and waste disposal problems. This work proposes the use of a variety of heterogeneous catalysts to achieve good results for condensation Claisen-Schmidt reaction in terms of conversion and chalcones selectivity, when compared to the homogeneous catalysis. Two groups of catalysts were tested: metal oxides and activated carbons. Magnesium oxide catalysts were prepared by hydrothermal treatment and magnesium, niobium, lanthanum and titanium oxides by rehydration of commercial precursors, all methods followed and not followed by cesium impregnation. The activated carbons used as catalysts were Babassu, Bahia Coconut, ox bone and Dendê, raw and treated with sodium hydroxide. The catalysts were characterized by scanning and transmission electron microscopy, thermogravimetric analysis, differential thermal analysis, determination of the specific superficial area by the adsorption/desorption of N2 at 77 K method, infrared spectroscopy, X-ray diffraction and temperature-programmed desorption of CO2 and NH3. The basic sites of carbons were quantified by Boehm Method. Finally, the performance of the catalysts was evaluated on the Claisen-Schmidt reaction between Acetophenone and 4-nitrobenzaldehyde, and the conversion was quantified by high performance liquid chromatography. The best catalyst was treated babassu activated carbon, whose conversion achieved was 92,38%.Item Estudo da eficiência do pré-tratamento do bagaço de abacaxi com perôxido de hidrogênio alcalino em diferentes granulometrias na obtenção de açúcares redutores totais(Universidade Federal de Goiás, 2016-04-18) Macedo, Lorena Costa Vasconcelos; Freitas, Fernanda Ferreira; http://lattes.cnpq.br/0883086742146577; Seolatto, Araceli Aparecida; http://lattes.cnpq.br/1495882445078650; Seolatto, Araceli Aparecida; Freitas, Fernanda Ferreira; Rosa, Paula Rúbia Ferreira; Caliari, MárcioThis study examined the performance of pineapple bagasse for the production of reducing sugars after pretreatment with alkaline hydrogen peroxide and acid and enzymatic hydrolysis. They were determined after conducting preliminary acid and enzymatic hydrolysis the best conditions for the bagasse pineapple used in dry form, "in natura" and washed. Chosen the dry pomace condition, this was separated granulometrically, wherein the average diameter fractions of 1.242 mm and 0.564 mm were predominant among the amounts of sieved bagasse, these two fractions were then chosen and denominated 20 and 48 mesh respectively, to evaluate the influence of particle size on the release of total reducing sugars. Type DCCR designs were conducted to evaluate the influence of weather pretreatment (h) Temperature (°C) and concentration of alkaline hydrogen peroxide (%) in the performance of acid and enzymatic hydrolysis, which was measured by the release of total reducing sugars (TRS). Moreover, the mass loss caused in the samples 20 and 48 mesh after pretreatment with alkaline hydrogen peroxide were observed. The results showed that the highest yields of reducing sugars obtained for fractions 20 and 48 mesh, both the acid hydrolysis with diluted sulfuric acid 2.9% (v/v) as the enzymatic hydrolysis with 9 FPU / g dry biomass at 50 °C and pH 4.8, were obtained when using lower levels of time, temperature and concentration of peroxide to the pre-treatment with hydrogen peroxide. The ART mass analysis after 8 h of reaction at 20 °C and concentration of alkaline hydrogen peroxide at 2% (v/v) to acid and enzymatic hydrolysis at residue 20 mesh, were 0.092 g/g ART dry bagasse and 0.063 g/g of dry bagasse ART respectively. As for the enzymatic and acid hydrolysis in the residue 48 mesh under the same conditions was 0.074 g/g dry bagasse ART and 0.058 g/g ART respectively. Therefore, it is believed that the smaller mass loss is related to obtaining higher yield of reducing sugars. This is because, observing the mass losses of such biomasses intended to acid and enzymatic hydrolysis, in both fractions pineapple pulp, 20 and 48 mesh after pretreatment with alkaline hydrogen peroxide were detected smaller mass loss of 77.829% and 83.182% for bagasse of 20 mesh and 83.724% and 83.493% for the bagasse of 48 mesh.Item Estudo da obtenção de açúcares redutores totais a partir do bagaço de laranja (Citrus sinenses) por hidrólises ácida diluída e enzimática(Universidade Federal de Goiás, 2016-04-18) Nogueira, Danielle Pires; Freitas, Fernanda Ferreira; http://lattes.cnpq.br/0883086742146577; Seolatto, Araceli Aparecida; http://lattes.cnpq.br/1495882445078650; Seolatto, Araceli Aparecida; Freitas, Fernanda Ferreira; Rosa, Paula Rúbia Ferreira; Suarez, Carlos Alberto GaleanoDue to the recent research for new fuels from renewable sources ethanol has been gaining momentum, because it can be produced from diverse raw materials, such as agro-industrial residues. The objective with this work was to study the production of reducing sugar by dilute acid, and enzymatic hydrolysis of the orange bagasse from juice industry. The orange bagasse was collected, cut into pieces, and crushed. Granulometry, and the contents of moisture, ashes, holocellulose, cellulose, hemicelulose, soluble and insoluble lignin were determined. The pre-treatment was done with calcium hydroxide following what was previously tested by Silva et al. (2013). A pre-test of the enzymes combination was done using 2 g of pre-treated biomass, in dry base, using 3 FPU/mL of cellulase, and 0 U/g and 3 U/g of xylanase. For the hydrolysis two central composite factorial 2³ designs were done, with the answer in total reducing sugars (ART). For the dilute acid hydrolysis the factors were HCl concentration, temperature, and time, and for the enzymatic the concentrations of cellulase and xylanase and time. The granulometry showed that 47.75% of the biomass with diameter over 0.833 mm, 32.84% of the biomass with an average diameter of 0.564 mm, and 19.41% of the biomass with diameter under 0.295 mm. The moisture content prior to drying was 84.69% and 7.38%, the ashes content was 3.79%. The cellulose content was 22.90% and the hemicellulose was 3.39%. The lignin content was 9.90%. The reducing sugar results for the acid hydrolysis varied from 9.32±0.68 mg ART per g of biomass to 30.15±0.31 mg ART per g biomass, the most significant factor was temperature, and the least was time. It was not possible to find the optimum region with the studied factors. The reducing sugar results for the enzymatic hydrolysis varied from 75.33±3.82 mg ART per g biomass to 99.66±0.62 mg ART per g biomass, the most significant factor was the cellulase concentration, and the least significant the xylanase concentration. The studied factors did not show the optimum region to maximize the reducing sugars content. The enzymatic hydrolysis produced larger concentrations of reducing sugars than the acid hydrolysis.Item Otimização numérica da produção de glutationa por saccharomyces cerevisiae utilizando subprodutos industriais(Universidade Federal de Goiás, 2016-05-02) Cruz, Késia de Souza; Geraldine, Robson Maia; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4792431Y6; Castiglioni, Gabriel Luis; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4778449D6; Castiglioni, Gabriel Luis; Geraldine, Robson Maia; Freitas, Fernanda Ferreira; Putti, Fernando FerrariRecent studies show that often, pathologies are caused by Reactive oxygen species (ROS). The ROS are associated with the oxidative stress in the cells. The body uses the antioxidants to defend itself from the consequences of this process. An example of an antioxidant with different functions in an organism is the Glutathione (GSH). It is a cellular thiol with low molecular mass, that’s synthesized by chemical, enzymatic and fermentative methods. Since it is environmentally and economically viable, the use of the fermentative process has gained scientific visibility. The use of mathematical models is an alternative that helps in the production of Glutathione. Considering these observations, the present study's aimed to elaborate a mathematical model for production and prediction of GSH for Saccharomyces cerevisiae, as well as to validate its numerical optimization experimentally. For the mathematical model in this process, was used the Central Composite Rotational Design 2², having as an answer, the GSH and biomass values in function with the concentration of molasses and glycerol during a period of 96 hours of fermentation. Based on these results, a hybrid model was made, having as a result, the specific rate of GSH formation. The final model was adjusted to a polynomial function using the method of least squares. Experimentally, the maximum production of GSH was found to be, in 72 hours (119,6 mg L-1) using 76,9 g L-1of molasses and glycerol, respectively. Applying the model for similar conditions, it was estimated to a 118,6mg L-1. The experimental results were then statistically analyzed to verify their similarity. The numerical optimization was made by setting the clock for 72 hours. At this step, the concentration of molasses and glycerol were varied until the best conditions to produce GSH were met. The optimization helped to derive an estimate that 70 g L-1of sugar cane molasses and 40 g L-1of glycerol can guarantee the production of 126 mg L-1of GSH. Based on the accuracy of the observations, the same conditions were used as a central point for the validation of the model - Factorial Design2². The results obtained under these conditions helped establish that the central point of the proposed design for the validation of the model, is 127,3mg L-1of GSH in 72 hours. The validation of this mathematical model by the numerical optimization proved that it was effective for the production and prediction of Glutathione by Saccharomyces cerevisiae, using industrial by-products.Item Síntese de nanopartículas de óxido de ferro funcionalizadas para remoção de Pb2+(Universidade Federal de Goiás, 2016-05-30) Matos, Hannah Larissa Siqueira; Lima, Emília Celma de Oliveira; http://lattes.cnpq.br/0176904550618260; Ostroski, Indianara Conceição; http://lattes.cnpq.br/9689394915288313; Ostroski, Indianara Conceição; Lima, Emília Celam de Oliveira; Martins, Paulo Roberto; Barros, Maria Angélica Simóes Dornellas deLead is a heavy metal that can be found in wastewaters of acid battery production, pigment and dye factories, petrochemical and automobile industries. It can cause serious damages to environment and human health even at trace level due to its bioaccumulation capacity. Numerous techniques are used for removal of heavy metals in wastewaters, the adsorption has been a technique of high efficiency and low cost with the use of alternative adsorbents, like nanoparticles. Iron oxide nanoparticles have low toxicity, they are biocompatible, and due to their small size, they have a huge surface area and high reactivity. In this study, colloidal suspensions of functionalized iron oxide nanoparticles with citrate were prepared using a modified coprecipitation methodology of Fe3+ and Fe2+ ions in basic medium. With the purpose of simplifying the synthesis to possible uses of nanoparticles in large scale, the colloidal suspension was obtained in one step and subsequent steps in the synthesis, such as washing and drying, were dismissed. Moreover, this synthesis does not generate waste, it has low cost, and simple application. The nanoparticles were characterized by X-ray diffraction, infrared spectroscopy, transmission electron microscopy, point of zero charge, and molar ratio [Fe3+]/[Fe2+]. Colloidal suspensions were used for removal of Pb2+ in synthetic solutions. For this, studies were conducted to evaluate the influence of synthesis modifications in removal of metal ions, the pH and metal concentration effect, as well as the mechanisms of adsorption, kinetic and thermodynamics parameters. VIII It was observed that besides the adsorption process, nanoparticles were coagulated and precipitated, up tp 97% of Pb2+ removal in was obtained in high metal concentration. Thus, due to coagulation another step of separation was not necessary, which could be costly in wastewater treatment.Item O estudo de adsorção dos corantes azul royal tiafix e preto tiassolan utilizando o carvão de osso como adsorvente(Universidade Federal de Goiás, 2016-07-08) Moura, Rowander Alexandre; Freitas, Fernanda Ferreira; http://lattes.cnpq.br/0883086742146577; Seolatto, Araceli Aparecida; http://lattes.cnpq.br/1495882445078650; Ostroski, Indianara Conceição; Oliveira, Sergio Botelho de; Freitas, Fernanda FerreiraThis project aimed to carry out the study of adsorption of dyes called AR.TF and P.TS using bone char as an adsorbent. To determine the physical characteristics of char were used the particle size analysis techniques, adsorption and desorption of N2 at 77K, scanning electron microscopy and X – ray diffraction. Regarding the coal chemical nature was employed the techniques infrared spectroscopic and point of zero charge (PZC). It was conducted adsorption kinetics for the determination of the adsorption equilibrium time, being achieved in approximately 1 hour and 30 minutes to the AR.TF dye and 4 hours and 50 minutes to the P.TS dye. The experimental data obtained in the adsorption kinetics were fitted to the kinetic model pseudo first order pseudo second order and intra particle diffusion model having been pseudo second order best represented the adsorption of both dyes. It was used a 23 factorial design of the central composite type, being the variables agitation, temperature and pH and quantified response the adsorption capacity (q). With this, it became possible to analyze the influence of factors as well as the interactions between them, collaborating with obtaining the influence of the independent variables on the response study. Finally, it was performed the experiments at different temperatures for constructing the adsorption isotherms, by adjusting the values at the Langmüir and Freundlich models. For dyes AR.TF and P.TS had to be a better adequacy of the data to the Freundlich model, but it is important to note that some data are also adjusted well to the Langmuir model. Through this fact makes it possible to hypothesize the coexistence of two adsorption kinds at the adsorption process of dyes of this project. Generally the bone char showed acceptable as adsorbent for the adsorption of AR.TF and P.TS dyes having a higher removal efficiency for the dye AR.TF.Item Otimização de reator batelada alimentada para hidrolise de palha de cana de açúcar aplicando a teoria do controle ótimo(Universidade Federal de Goiás, 2016-09-30) Pinto, Vitor Debiazzi Pereira; Suarez, Carlos Alberto Galeano; http://lattes.cnpq.br/5911055089145779; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Montano, Inti Doraci Cavalcanti; http://lattes.cnpq.br/8547423775951223; Suarez, Carlos Alberto Galeano; http://lattes.cnpq.br/5911055089145779; Sousa Junior, Ruy de; Freitas, Fernanda Ferreira; Horta, Antonio Carlos LuperniFrom the economic point of view it is important to process high charges of solid in enzimatic hydrolysis of the lignocellulosic residues for the production of 2G ethanol, but batch operation with high initial charges of substrate can cause inefficient mixture, damaging the reactional process. An attractive alternative is operating the reactors in fed batch. The aim of this work was to determine, applying the theory of optimal control, the optimal feeding profile of substrate in bench reactor. For this, it was tested two kinetic of Michaelis-Menten: pseudo-homogeneous Michaelis-Menten kinetic and Michaelis Menten kinetic with inhibition by the product, in the last kinetic was obtained the best fit to experimental data. The developed algorithm was run in Matlab® software and the simulation results were experimentally validated. Enzymatic hydrolysis assays were performed with hydrothermally pre-treated sugar cane straw followed by the alkaline delignification. It was obtained good fiting of the simulation data with respect to the experimental data, with values of glucose final concentration close to 164.647 g/L (triplicate average) and in simulation the concentration was 174.93 g/L. Proving that the sugar cane straw, besides being a good feedstock cheap and abundant, it has a great energetic potential. Furthermore, the optimal control strategy was very efficient in optimization of the proposed problem.Item Simulação de uma unidade piloto de destilação de água empregando energia solar(Universidade Federal de Goiás, 2016-12-21) Damasceno, Camila Teles; Noda Pérez, Caridad; http://lattes.cnpq.br/8518548259609686; Noda Pérez, Caridad; Costa, Orlene Silva da; Oliveira, Sérgio Botelho deThis work proposes the use of a distiller that uses solar energy for the production of distilled water suitable for use in chemical analysis laboratories of the Federal University of Goiás (UFG).The choice of solar distiller is due to the high incidence of solar radiation in Brazil, and because this type of equipment does not consume electricity, does not generate wasted drinking water, is easy to operate and requires low technology.A study was carried out on the intensity of radiation incident in the dry winter and wet summer period of the municipalities of Catalão, Goiânia and Jataí, where the campus of this university is located, based on the Duffie and Beckman model (2013).From the generated radiation data it was possible to determine what 20º would be the best angle for the equipment coverage, so the pilot model was built and installed at the Chemistry Institute of UFG in the city of Goiânia.With the experimental data of water temperature (Tw) and the distiller cover (Tg) recorded every hour (from 8 a.m. to 6 p.m.), the distiller's energy balance, based on the Dunkle model ( 1961), by which it was calculated the heat transfer coefficients by convection (hcw) and evaporation (hew), convective heat transfer rates (qcw) and evaporation (qew), mass transfer rate ( ew) and the efficiency of the distiller (ηi).The results obtained allowed to conclude that the coefficient of heat transfer by evaporation and its corresponding rate were higher than the coefficient of heat transfer per convection and its respective rate.The production of distilled water in winter and summer was 0.31 and kgm-2dia-1, respectively, and the distiller's maximum efficiency was 5.4% in winter and 41.33% in summer. The obtained water meets the parameters of the Brazilian Pharmacopoeia and can be used in chemical laboratories in substitution to that obtained in the electric distillers.Item Processamento e avaliação da estabilidade de extrato hidrossolúvel a base de castanha-do-Brasil (Bertholletia excelsa) e baru (Dipteryx alata Vogel)(Universidade Federal de Goiás, 2017-02-23) Silva, Kamilla Soares; Silva, Flávio Alves da; http://lattes.cnpq.br/1713250447051507; Cardoso, Cláudio Fernandes; http://lattes.cnpq.br/5163369332806586; Cardoso, Cláudio Fernandes; Silva, Flávio Alves da; Freitas, Fernanda Ferreira; Viana, Letícia Fleury; Goulart, Gilberto Alessandre SoaresTo elaborate a better combination of Brazil nut (Bertholletia excelsa) and Baru (Dipteryx alata Vogel) in the development of the mixed water-soluble extract, with good physicochemical, physical and biological stability, a simplex centroid type mixture delineation was performed, a mixture between Brazil nut, Baru almond and water. The Brazil nut and Baru almond water-soluble extract obtained was packed in 220 mL glass bottles and pasteurized in stainless steel casing, then cooled and stored under refrigeration (4 degrees) until the physicochemical, physical, microbiological and sensory determinations. The determinations were performed in triplicate and the results were analyzed by the Statistica software and the mathematical models were generated, tested and validated. In order to obtain a better acceptance of the beverage, in both most accepted extracts in the sensorial analysis a fixed amount of 10,00% (w/v) sugar was added and the amount of preservatives for the reduction of residual taste, reduced. After the definition of the best mixture formulation, determined by global acceptance and purchase intention parameters, the water-soluble extract with the best grade was reprocessed in large scale and stored during 28 days, under 4 degrees refrigeration, evaluating the rheological profile and keeping up with the evolution of physicochemical, microbiological and sensorial analysis parameters. The formulation of water-soluble extract composed by 69.17% (w/w) of water, 9.17% (w/w) of Brazil nut and 21.67% of 10,00% (w/v) sucrose Baru almond was the favorite in the global acceptance test. The mathematical models obtained by the simplex centroid planning achieved better adjustments with the special cubic model proving to be highly predictive. The water-soluble extract presented non-newtonian pseudoplastic fluid behavior. The microbiological determinations did not demonstrate contamination of the beverage over the refrigerated storage time, indicating adequate hygienic handling during the processing and its good biological stability.Item Estudo da competência de Saccharomy cescerevisiae em co-cultura para a produção de etanol(Universidade Federal de Goiás, 2017-02-24) Santos, Mayara Vieira; Souza, Adriana Régia Marques; http://lattes.cnpq.br/3723989528702465; Castiglioni, Gabriel Luis; http://lattes.cnpq.br/6050198962131737; Castiglioni, Gabriel Luis; Oliveira, Bruno Motta; Freitas, Fernanda FerreiraUsually the inoculum used during the beginning of the harvest of ethanol production is constituted by the combination of two or more yeasts strains and in the end the most adapted one will predominate, either inoculated yeast or indigenous wild yeast. The proportion used in these industries are established empirically, of which little is known about the kinetic parameters and the influence that each yeast has on the production of ethanol and on the other metabolites. An experimental design from the blending design with Saccharomyces cerevisiae ATCC7754, S. cerevisiae CAT-1, S. cerevisiae PEDRA-2, S. cerevisiae MONASTRELL strains was proposed to understand how the interaction among the different blends occurs comparing with the ethanol, biomass, acetic acid, glycerol and biomass consumption. This study showed that the inherent characteristics to each yeast can influence the behavior of the kinetics parameters of the culture with two yeasts. It was verified that the combination among three yeasts presented similar metabolic behavior. From the blending design it was possible to elaborate mathematical models that predicts the ethanol, biomass, glycerol, acetic acid and residual sucrose amount in all four yeasts mixtures. It was also possible to identify that the mixture of CAT-1 and PEDRA-2 presented higher ethanol production when cultivated in a 1: 1 ratio, and also in the cultivation with the two yeasts (CAT-1 and PEDRA-2) to CAT-1 was higher in yeast. This research also presents the synthetic cane juice composition and the detail of growth kinetics, substrates consume and production of MONASTRELL yeast products that had not been studied until now.Item Catalisadores heterogêneos aplicados à reação de Biginelli(Universidade Federal de Goiás, 2017-03-07) Nascimento, Letícia Gomes do; Oliveira, Guilherme Roberto de; http://lattes.cnpq.br/8239498431579015; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Oliveira, Guilherme Roberto de; http://lattes.cnpq.br/8239498431579015; Andrade, Fabiano Molinos de; Arroyo, Pedro AugustoThe Biginelli reaction involves the cyclocondensation of three reagents in the presence of an acid catalyst to obtain dihydropyrimidinones (DHPMs).This compound and its analogues are widely known to possess various pharmacological properties, such as antibacterial, antiinflammatory, antifungal, antiviral, anticancer and antihypertensive. This reaction is usually carried out via homogeneous catalysis, which presents, however, some difficulties, such as regeneration of the catalyst and difficult separation of the final product, thus becoming an obstacle for industrial use. In the present work, it was proposed the use of two classes of heterogeneous catalysts, which are: metal oxides and acid carbons in order to achieve attractive characteristics in the Biginelli reaction, as a reduction of reaction time and increase in yield. The acidic carbons were prepared by carbonization by impregnation of agroindustrial residues with sulfuric acid at a temperature of 200 °C in the mass ratio of 1:10 (precursor: H2SO4) for 6 h. The pure HY-340 and Nb2O5 were both tested and chemically treated with a solution of 30% sulfuric acid. The catalysts were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric (TG), differential thermal analysis (DTA), textural adsorption/desorption analysis of N2 at -196 °C and desorption of ammonia at programmed temperature (DTP-NH3), scanning electron microscopy (SEM) and X-ray Dispersive Energy Spectrometry (EDS). The contents of C, N, O and S present on the surface of the coals were quantified by Elementary Analysis (CHNS-O). Exploratory catalytic tests were carried out to define the best experimental conditions of solvent, temperature, molar ratio and amount of catalyst. The results obtained allowed to establish the best experimental conditions for the realization of the Biginelli reaction. Thus, the following parameters were adopted to evaluate the performance of the different catalysts. These are: 5% catalyst content (by mass), molar ratio of 1 Benzaldehyde: 1,5 Methyl acetoacetate: 1,5 Urea, without solvent and temperature of 130 °C. The best catalyst was Nb2O5 treated with sulfuric acid, whereby a yield of 94% of dihydropyrimidinones (DHPMs).Item Adsorção de compostos nitrogenados utilizando carvão ativado(Universidade Federal de Goiás, 2017-06-22) Ferreira, Maria Eugênia de Oliveira; Alonso, Christian Gonçalves; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4777466U2; Ostroski, Indianara Conceição; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4751610A4; Oliveira, Sérgio Botelho de; Vaz, Boniek Gontijo; Alonso, Christian GonçalvesHeavy petroleum fractions, especially the vacuum residue, concentrate the largest amounts of nitrogen compounds. Such compounds are considered contaminants of the refining process, and interfere in the conversion steps to obtain lighter derivatives from the heavy fractions. In this study, the aim was to evaluate the removal of nitrogen compounds by adsorption process. Quinoline solution solubilized in toluene was used as a synthetic filler. Commercial activated carbons from coconut shell of babaçu and dendê in their original form and chemically modified with concentrated solutions of nitric and sulfuric acid, as well as sulfonated carbon developed from the rice husk, were evaluated for the adsorption capacity against compounds nitrogen residues present in the vacuum residue and synthetic charge. The textural characteristics of the adsorbents were also evaluated, in which it was observed that the modification with acid reduces the specific area of the activated carbons, but it promotes an increase in the removal of quinoline from the medium. From the preliminary batch adsorption test, the activated carbon from dendê treated with sulfuric acid (CDAS) was able to remove 67.08% of the quinoline present in the solution and was selected for kinetic and equilibrium study. The adsorption kinetics of quinoline were relatively fast for the three concentrations studied (500, 2000, 5000 mg L-1), reaching equilibrium after 240, 120 and 60 minutes of contact, respectively. The kinetic data for the three systems fit the pseudo-second order model better. The equilibrium data were better adjusted to the Freundlich model, revealing the physisorption character of adsorptive process. The maximum adsorption capacity obtained by Langmuir model was 56.63 mg g-1. The results show that CDAS is a promising adsorbent for the removal of quinoline in organic medium. In relation to the vacuum residue sample, batch adsorption tests were conducted in such a way to ascertain the efficiency in class N removal. The results of Mass Spectrometry, ESI (±) Orbitrap MS, showed that the adsorbents CBB and CBAN were more selective in the removal of the non-basic nitrogen compounds, while the basic nitrogenous ones were more persistent and were not removed by any of the adsorbents tested.Item Investigação do processo oxidativo avançado (UV/H2O2/carvão ativado) no tratamento de efluentes industriais: eliminação de fenol(Universidade Federal de Goiás, 2017-06-30) Martins, Michelly Freitas de Moraes; Oliveira, Tatianne Ferreira de; http://lattes.cnpq.br/2017895913160804; Castiglioni, Gabriel Luis; http://lattes.cnpq.br/6050198962131737; Castiglioni, Gabriel Luis; Oliveira, Tatianne Ferreira de O; Ostroski, Indianara Conceição; Sá, Fernando Pereira deDue to the need for more efficient technologies for the phenol elimination in effluents, the objective of this study was to evaluate the efficiency of the UV/H2O2/AC process and the adsobent behavior in the coupling to eliminate phenol. For a determination of the physical characteristics of the activated carbon, a textural analysis was carried out for isotherms of adsorption and desorption of N2 at 77 K, scanning electron microscopy, thermogravimetric analysis and differential thermal analysis. Regarding the chemical nature of the coal were carried out as techniques of infrared spectroscopy, elemental analysis, Boehm method and zero load point. Adsorption kinetics were used to determine the adsorption capacity, for each of the 11 tests, according to the experimental design 23 + 3 central points, where the pH, temperature and the quantity of carbon activated varied. The experimental data obtained in adsorption kinetics were adjusted to the kinetic models of pseudo-first order, pseudo-second order and intraparticle diffusion, with pseudo-second order being the best represent the adsorption process of all the tests. Adsorption isotherms (15, 30 and 45°C) were then adjusted, adjusting the values to the Langmuir and Freundlich models. All feared a better fit of the data to the Freundlich model. For the treatments H2O2/UV and H2O2/UV/AC a factorial design 22 + 3 central points was used, varying pH and H2O2 concentration and quantified response by rate of phenol removal. For both treatments the pH showed a negative release on elimination rate and a concentration of H2O2 showed positive effect. The best tests for H2O2/UV and H2O2/UV/AC processes were the central points (pH 7 and 20 mmol H2O2), with phenol elimination rates of 89% and 94.16%, respectively. With the presence of a free radical inhibitor (tert-butanol) the kinetic contribution of the hydroxyl radicals was calculated, showing that 77.64% of the phenol elimination in the H2O2/UV/AC treatment was caused by their action. The H2O2/UV/AC coupling process is acceptable, presenting a higher removal rate than the adsorption process with much shorter removal time.Item Tratamento de efluente da indústria de cosméticos via reagente de Fenton e adsorção(Universidade Federal de Goiás, 2018-04-04) Pereira, Lisiée Manzoli Gonçaves; Brito, Núbia Natália de; http://lattes.cnpq.br/9075769086344855; Ostroski, Indianara Conceição; http://lattes.cnpq.br/9689394915288313; Ostroski, Indianara Conceição; Brito, Núbia Natália de; Seollato, Araceli Aparecida; Schneider, Roselene MariaThe effluent generated by the cosmetic industries, from industrial processes, tank washes and disposal of failed batches, are highly recalcitrant due to their complex chemical composition. The deposition of such liquids into water bodies must follow a series of environmental parameter values established by local and federal legislation so that they do not negatively affect the receiving environment and its ecosystems. Traditional wastewater treatment methods sometimes fail to satisfactorily remove their contaminating potential. Therefore, this work aims at integrating two treatment technologies, Fenton’s reagent and adsorption, in order to achieve maximum removal efficiency in the values of environmental and water quality control parameters. Wastewater from a cosmetics industry in the metropolitan area of Goiania (state of Goias, Brazil) was used as object of this study. The environmental parameters analyzed were: color (via absorbance analysis), total iron, organic matter (via chemical oxygem demand analysis), total phenols, pH, turbidity, conductivity, dissolved oxygen, initial and residual H2O2 and total solids. They were analyzed on the pretreated wastewater, after the Fenton’s reagent treatment, after adsorption, and after the combined processes. The adsorbent was characterized by elemental analysis (CHN), thermogravimetry (TG/DTA), adsorption and desorption of N2 and infrared spectroscopy. In the Fenton’s reagent treatment, factorial design 23 was performed for the factors: Fe2+ and H2O2 concentrations and pH, in order to outline the process parameters. From these data, other Fenton assays were performed by opening Fe2+, H2O2 and pH concentration bands to evaluate their influence on the removal of the environmental parameters mentioned above. The best results were obtained in Fe2+ 184.21 mg L-1; H2O2 concentration at 1300 mg L-1, and pH at 3.5. Subsequently, the wastewater treated via Fenton’s reagent was subjected to the adsorption process, in which seven types of activated carbon were tested. The activated charcoal which presented the best efficiency at removing environmental parameter values was submitted to kinetic tests at different temperatures and contact times. The equilibrium time was reached in 16 minutes (tested in the range of 4min to 24h), and for the different temperatures it was observed that its increase did not contribute significantly to the process efficiency (tested in the range of 20 to 60ºC). The integration of the two technologies presented the following percentages of global variation: chemical oxygem demand: -73.58%; turbidity: -97.65%; conductivity: -5.36%; dissolved oxygen: + 141.24%; total phenols: -81.77%; total iron: -69.97%; hydrogen peroxide: -97.78%; total solids: -46.37%; total fixed solids: -30.57%; total volatile solids: -46.65%; absorbance at 200 nm: -36.38%; absorbance at 400 nm: -77.37%. The pH, total iron and hydrogen peroxide parameters were controlled in the Fenton’s reagent process.Item Estudo de metabolismo da Saccharomyces cerevisiae para produção de glutationa utilizando melaço de beterraba(Universidade Federal de Goiás, 2018-08-27) Paixão, Julliana Nazareth Vieira da; Castiglioni, Gabriel Luis; http://lattes.cnpq.br/6050198962131737; Castiglioni, Gabriel Luis; Rodriguez, Armando Garcia; Suarez, Carlos Alberto GaleanoGlutathione is classified as a linear, water-soluble tripeptide, consisting of glutamic acid, L-cysteine and glycine being obtained through the synthesis of consecutive enzymatic reactions, which has innumerable intracellular metabolic functions, its main function is to avoid the cellular oxidation. Recent studies, indicate that GSH’s (glutathione) function disorder, is involved by the etiology of some diseases such as: liver cirrhosis, pulmonary, gastrointestinal, inflammation in the pancreas, diabetes, neurodegenerative diseases, among others. In addition, GSH stands out in the environmental area as an important biological parameter, had been being one of the most important indicators of oxidative stress. Considering these factors, the aim of the present research is to evaluate the glutathione production by Saccharomyces cerevisiae using agroindustry’s residues. Supplying better conditions to determinate glutathione production. By means of a CCD (Central composite design) 22 with four central points and four-star points, begetting twelve experiments, the fermentation tests were carried out. In the twelve batch experiments, the concentration of sucrose present in beet molasses (61 – 139 g. L- 1) and ammonium sulfate (NH4)2SO4 (1 – 12 g. L- 1) had been varied as a source of nitrogen. In order to settled the cellular concentration, sucrose, ethanol, glycerol, acetic acid (g. L-1) and glutathione (g. L- 1), aliquots of each experiment were withdrawn every 12 hours until the end of the fermentation process with 48 hours, carried out the proper of analyzed each metabolites. From the results obtained, a mathematical model had been established, in which, was predicted the behavior of cell growth and the fermentation products yield, with reference the relation by the best conditions for the glutathione formation presented. In addition, the qPCR(Real-time Polymerase Chain Reaction) technique was applied, to evaluate the efficiency of GSH1 and GSH2 genes. The best result had been observed with 24 hours of fermentation 7,61 g.L-1of glutathione formation which, in the experimental concentration condition of 61 g. L-1 of sucrose present in molasses and 6.5 g.L-1 of ammonium sulfate.Item Estudo de co-cultura entre Saccharomyces cerevisiae e Saccharomyces kudriavzevii para elaboração de uma bebida alcoólica fermentada à base de Cagaita (Eugenia dysenterica DC.)(Universidade Federal de Goiás, 2018-08-27) Valério Júnior, Marcos Flávio Ribeiro; Castiglioni, Gabriel Luis; http://lattes.cnpq.br/6050198962131737>; Freitas, Fernanda Ferreira; http://lattes.cnpq.br/0883086742146577; Freitas, Fernanda Ferreira; Castiglioni, Gabriel Luis; Rodriguez, Armando Garcia; Seolatto, Araceli AparecidaThe production of alcoholic ferments from fruit is an attractive alternative for the food industry, as this type of beverage has received strong acceptance from consumers. Climate change and the search for wines with lower alcohol content and a search for a concentration of glycerol and better aromas, led to studies in yeast co-cultures. Brazil is one of the world's largest producers of fruits, including tropical fruit. Among the typical species of Cerrado, Eugenia dysenterica DC, popularly known as Cagaita, is already used in the manufacture of sweets, jellies, ice cream, soft drinks, juices and liqueurs. Regarding the fermenting agent, yeast to Saccharomyces cerevisiae, with high potential for ethanol production, and Saccharomyces kudriavzevii, a notable producer of glycerol, present interesting and required characteristics in the fermented beverage industry. Thus, the present work followed a central rotational experimental planning and a common factorial planning to stipulate the concentration of the strains of Saccharomyces cerevisiae T-73 and Saccharomyces kudriavzevii CR-85, in order to understand how the interaction between the yeasts occurs ethanol, biomass and glycerol responses. From the DCCR, it was not possible to obtain significant models, since experiment 5 where there was pure CR-85 strain did not produce ethanol and glycerol. From these results, it was followed by common factorial planning, in which mathematical models could be obtained for the prediction of ethanol, biomass and glycerol production. It was also possible to identify that the assay with the highest concentration of CR-85 had an increase of glycerol, and the assay with the highest ethanol production was one that contained a slightly higher content of T-73 compared to CR-85. As for the volatile compounds, isoamyl alcohol was identified, responsible for the aromas in the food industry, as well as ethyl acetate, considered an ester acetate that gives the drinks fruit aromas. This research also presents details of the kinetics of growth, substrate consumption and production of Saccharomyces cerevisiae T-73 and Saccharomyces kudriavzevii CR-85 yeast products, in which the characteristics inherent to each yeast can influence the behavior of the kinetic parameters, characterizing the need to deepen studies on the metabolism of these yeasts.Item Estudo da extração e purificação de ficocianina e aloficocianina da biomassa de Arthrospira platensis(Universidade Federal de Goiás, 2018-08-29) Caetano, Renata Klícia Mendes; Ferreira, Fernanda Freitas; http://lattes.cnpq.br/0883086742146577; Castiglioni, Gabriel Luis; http://lattes.cnpq.br/6050198962131737; Castiglioni, Gabriel Luis; Freitas, Fernanda Ferreira; Rodriguez, Armando Garcia; Montano, Inti Doraci CavalcantiThe growing interest in bioactive compounds from renewable natural sources has stimulated more and more studies aimed at increasing the supply of this market. An example is phycobiliproteins, dyes used in various areas, such as food, pharmacological and cosmetic. The microalgae arthrospira platensis (Spirulina platensis) is one of the organisms that stands out most in the production of these dyes, producing allophycocyanin and phycocyanin; these two dyes are the ones that today have more demand in the market. These proteins have their application determined from their degree of purity obtained with the absorbance ratio read at 620 nm of the extract used for the absorbance read at 280 nm. For use of these dyes, in the food area, a purity value greater than 0.7 should be obtained, and for use in the analytical area, the purity should be greater than 4.0. In view of the importance of these dyes and their degree of purity, in order to develop means of obtaining phycobiliproteins in a purity satisfactory for use in food industries, phase separation techniques were used in aqueous biphasic systems (ABS) to evaluate the action of pH, phosphate salt concentration and the concentration of low chlorine content cationic polymer and polyethylene glycol 4000 (PEG 4000) on the efficiency of the extraction and purification process of Spirulina crude extract and also in the pre-purified extract of phycocyanin obtained by centrifugation. For this, a first experiment was carried out using a factorial design 2 4 to evaluate the variables that most influenced the extraction and purification of phycocyanin, allophycocyanin and purity of the extract. Values of 2.6 mg.mL -1 were reached for phycocyanin concentration, 1.4 mg.mL -1 for the allophycocyanin concentration and 1.6 for the purity of the extract. The significance of the PEG 4000 and PBC polymers was observed for extraction and purification of phycobiliproteins. Then, a second design was carried out, a Rotational Central Composite Design (RCCD) 2 2 , fixing the phosphate salt, pH and varying the PEG and low chlorine content cationic polymer concentrations. At the end of the extraction, it was possible to find concentrations of 2.7 mg.mL -1 for Phycocyanin, 1.3 mg.mL -1 of allophycocyanin and 2.5 for the purity of the extract, evidencing that the techniques used are effective for the extraction process and purification of phycobiliproteins, in which the levels achieved allow their use and application in food industry.Item Catalisadores a base de Cu, Ni e Mg suportados em Al2O3 aplicados à gaseificação de etanol em meio contendo água em condições supercríticas(Universidade Federal de Goiás, 2018-09-28) Melo, Jarbas Almeida de; Souza, Thiago Leandro de; http://lattes.cnpq.br/7431199944070783; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Alonso, Christian Gonçalves; Souza, Thiago Leandro de; Santos, Dyrney Araújo dos; Queiroz Júnior, Luiz Henrique KengIn this work the synthesis of catalysts was carried out with the objective of H2 production from gasification of ethanol in medium containing water under supercritical conditions. Based on reports from the literature, Cu, Ni and Mg were selected as components for the active phase, alumina (Al2O3) as catalysts support. The catalysts were prepared from aqueous solutions of nitrate salts precursors of Cu, Ni and Mg. The catalysts were characterized by X-ray fluorescence (FRX), scanning electron microscopy, thermogravimetric and thermal differential analysis (TG/ATD), X-ray diffraction (DRX) and textural analysis by N2 adsorption / desorption isotherms at -196 ° C. The TG/ATD analysis indicated that the calcination of the catalytic precursors was sufficient for the removal of water and decomposition of the nitrates of the metal salts precursors of the active phase. In the FRX analysis, the increase in the concentration of the metals in relation to the nominal values after the synthesis of the catalysts was characterized, with an increase of 20 to 40% depending on the metal due to the loss of water from the alumina support. The FRX analysis of the catalysts used in the catalytic tests shows that there was no significant leaching during the gasification process. DRX analysis have characteristic results that the metals are in amorphous form or dispersed in the form of small crystallites. Textural analysis of N2 adsorption / desorption isotherms indicated a reduction of approximately 60% in the specific surface area between the alumina and the calcined alumina and the specific area values between the alumina and the metal catalysts were kept close. The catalytic tests were performed at a pressure of 25 MPa and at temperatures of 400 to 650 ° C. A 10/1 molar water / ethanol solution was fed. In the catalytic tests H2, CH4, CO, CO2, C2H4, C2H6, C2H4O were obtained. The highest ethanol conversions were obtained at the temperature of 650 ° C for the catalysts NiO/Al2O3 and NiO-MgO/Al2O3, both 81%. The highest yield was 0.41 mol H2 / mol ethanol fed to the NiO / Al2O3 catalyst, at a temperature of 600 ° C. The highest selectivity at the temperature of 600 ° C was 39%, obtained by the NiO/Al2O3 catalyst.Item Análise termodinâmica da reforma com vapor de água de um composto modelo de bio-óleo para produção de hidrogênio(Universidade Federal de Goiás, 2018-09-28) Trevisan, Ivo Junior; Alonso, Cristian Gonçalves; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?metodo=apresentar&id=K4777466U2; Souza, Thiago Leandro de; http://buscatextual.cnpq.br/buscatextual/visualizacv.do?metodo=apresentar&id=K4250090T1; Souza, Thiago Leandro de; Alonso , Cristian Gonçalves; Cardozo Filho, Lucio; Oliveira, Sérgio Botelho de; Ostroski , Índianara ConceiçãoIn this work, a thermodynamic analysis of the water vapor reforming reaction of a bio-oil model compound was performed and the objective is producing hydrogen through an alternative source of fossil fuels. The bio-oil model compound was considered to be a molar fraction of 1:1:1 mixture of phenol, acetic acid and hydroxyketone and the thermodynamic data were obtained in DIPPR® software version 1.2.0. The chemical and phase equilibrium were calculated by the Gibbs energy minimization method. Constant pressure of 1 bar, temperature ratio from 673.15K to 1273.15K and water and carbon ratio of the substrate (H2O(v)/C(ent)) of 0.01 to 3.00 were used to construct the optimization problem and the software GAMS® version 2.0.29.8 was used by optimization problem resolution. The gas phase was considered with behavior of ideal gas and the solid phase was considered with solid carbon. Hydrogen, water, carbon monoxide, carbon dioxide, solid carbon and methane formation data were collected after solving the optimization problem and the reaction heat and syngas production were also analyzed. The maximum hydrogen yield obtained was 1.3 moles in the 1100 K region with 1 mole water per carbon of the substrate (H2O(v)/C(ent)). It was also observed that the greater amount of syngas occurs in the 950 K region and 1,2 of the H2O(v)/C(ent) ratio. An exothermic region and an exothermic region were observed in the reaction heat analysis and in the exothermic region there is a higher incidence of coke and methane generation and in the endothermic region a higher incidence of hydrogen and carbon monoxide generation.Item Desenvolvimento e avaliação de sistemas catalíticos heterogêneos para reações de acoplamento carbono-carbono de Suzuki-Miyaura(Universidade Federal de Goiás, 2019-02-21) Souza, Guilherme Botelho Meireles de; Oliveira, Guilherme Roberto de; http://lattes.cnpq.br/8239498431579015; Alonso, Christian Gonçalves; http://lattes.cnpq.br/7285754665946583; Alonso, Christian Gonçalves; Oliveira, Guilherme Roberto de; Ostroski, Indianara Conceição; Chagas, Rafael Pavão das; Matos, Ricardo Alexandre Figueiredo deSuzuki-Miyaura cross-coupling reactions are one of the most efficient and powerful tools for the formation of new carbon-carbon bonds, which have been widely applied in modern organic synthesis and industrial processes. Generally, these reactions are carried out by homogeneous catalysis, employing expensive palladium complexes such as PdCl2 associated with harmful phosphine ligands. However, these synthetic route presents several drawbacks such as high associated toxicity, catalyst recovery difficulties and waste disposal problems. In this context, several heterogeneous catalysts were proposed to overcome the great challenge of separation and recovery of homogenous catalysts. Also, a low-cost catalyst was presented as an alternative for the usage of palladium as the main Suzuki-Miyaura cross-coupling catalyst. Palladium, Nickel, Copper and Cobalt catalysts supported on niobium pentoxide (Nb2O5) were synthesized via wet impregnation method and tested for the Suzuki-Miyaura coupling reaction between phenylboronic acid and 4- bromoanisole. The catalysts were well characterized by scanning electron microscopy, N2 physisorption, X-ray diffraction, X-ray fluorescence, Thermogravimetry/Differential Thermal Analysis. Both Copper and Cobalt catalyst did not show any activity towards Suzuki- Miyaura cross-coupling reaction. Palladium catalyst resulted in high isolated yields (up to 91%) under optimized conditions. Satisfactory yields (up to 48%) were achieved employing the Nickel catalyst. Recycling tests were performed and significant loss in activity was observed after the first catalytic cycle, which can be attributed to catalyst loss during its retrieval by filtration between cycles, leaching of the active phase, in particular for Pd/Nb2O5 catalyst, or the poisoning by inorganic species (mostly potassium) on the spent catalyst’s surface.
- «
- 1 (current)
- 2
- 3
- »