Engenharia Química

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http://repositorio.ufes.br/handle/10/17472

Programa de Pós-Graduação em Engenharia Química

Centro: CCAE
Telefone: (28) 3552 8719
URL do programa: http://www.engenhariaquimica.alegre.ufes.br/pos-graduacao/PPEQ

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Agora exibindo 1 - 20 de 65

Atividade nematicida do fungo Pleurotus ostreatus e de suas proteases
(Universidade Federal do Espírito Santo, 2015-06-08) Genier, Hugo Leonardo André; Pinheiro, Iara Rebouças; Barañano, Audrei Gimenez; Soares, Filippe Elias de Freitas
Emprego da minimização da energia de Gibbs para predizer a composição dos gases de exaustão oriundos de uma caldeira que utiliza como combustíveis subprodutos gerados na indústria siderúrgica
(Universidade Federal do Espírito Santo, 2016-02-26) Turetta, Leticia Fabri; Costa, Andréa Oliveira Souza da; Costa Junior, Esly Ferreira da; Anastácio, Alexandre dos Santos
The development of the steel industry has increased energy demand, exerting strong influence on the use of energy resources. The utilization energetic is extremely important because it enables the steel industry greatly reduce their costs. In the steelmaking process, they are produced four by-products with high capacity for energy generation. The produced by-products are directed to thermoelectric plants and used as fuel for the generation of electricity. In this work it proposed a modeling for the prediction of the equilibrium concentration of the chemical species present in the furnace of a steel boiler installed in a thermoelectric plant. The employed technique consists of the minimization of the Gibbs energy of the reaction medium present in the furnace of steel boiler equipment on the thermoelectric central plant. The optimization problem was proposed, by defining thus the objective function and restrictions to be resolved employing the commercial software Matlab® . The solution of the optimization problem resultant provides the description of composition output of the exhaust gases. This work it was possible to evaluate the impact of changes in air feed flow rate and operating temperature of the composition of the exhaust gases. The applied methodology is able to reproduce satisfactorily the information provided by industry and obtained in the literature, that describe the combustion of the byproducts on the steel industry by-products.
Modelagem e simulação da fermentação alcoólica em batelada e contínua com múltiplos reatores em série
(Universidade Federal do Espírito Santo, 2016-02-26) Zanardi, Mayara dos Santos; Costa Junior, Esly Ferreira da; Carvalho, Raquel Vieira de; Costa, Andréa Oliveira Souza da
Ethanol stands out, compared to fossil fuels, because of its economic and environmental benefits. In Brazil, the second largest world producer, practically all ethanol production is obtained from the fermentation of saccharose (present in sugarcane). Improvements in the fermentation process for ethanol production could make it more competitive. In this context, this study has for objective develop a model for batch fermentation process of literature and a real industrial process that operates in a continuous mode with multiple reactors in series, using kinetic models from literature. The model for each component of interest was developed through transient mass balance on the reactor. The system of ordinary differential equations, resulting from the dynamic model, was integrated by the Runge-Kutta method of 4th order in Matlab® software. The estimation of kinetics parameters was performed by nonlinear optimization of an objective function by Nelder and Mead Simplex method. Two optimization strategies were adopted for the batch process: in the first strategy the µmax parameter is kept fixed and in the second this parameter is estimated. Six different kinetic models were tested. The estimated parameters were sensitive to small changes in experimental data set, moreover, the estimation of the parameter µmax had a strong positive influence on some models. The models Ghose and Tyagi (1979), Jin et al. (1981) and Tosetto (2002) showed the best performance in predicting the behavior of the concentration of the components in the reactor. The parameters of five kinetic models were estimated in the continuous process. The models that consider inhibition by product were better than those without this type of inhibition.
Aplicação de um esquema de simulação e monitoramento via filtro de partículas na produção de etileno a partir do etanol.
(Universidade Federal do Espírito Santo, 2017-02-13) Salardani, Luciana Souza Ferreira; Silva, Wellington Betencurte da; Dutra, Júlio Cesar Sampaio; Vieira, Fabrício Thiengo; Costa, José Mir Justino da
The present work discusses about the mathematical modeling, numerical simulation and the monitoring problem based on particle filter using single-point temperature measurements for the green ethylene production process from the catalytic dehydration of ethanol. With the scarcity of natural resources, the use of sustainable sources such as biomass instead of petroleum derivatives has been encouraged. For example, the ethylene required by the thermoplastics industry can be obtained from the catalytic dehydration of ethanol, which then generates green ethylene or bioethylene. Most of the published works about this process refer only to the synthesis of catalysts, mechanism and kinetics and no one were found considering the Bayesian estimation tool. Thus, the main contribution of this work is the proposal of an estimation scheme composed of a direct problem for the process simulation and generation of pseudo-measures, and by an inverse problem for the estimation of the interest variables by means of the particles filter. The numerical simulations allowed to understand the process and to locate the best position for the temperature sensor in the reactor. From the measurements of temperature, the proposed inferential tool estimates the latency variables and the unmeasured perturbations using the Sampling Importance Re-sampling Filter (SIR) algorithm. The filter performance is investigated according to the number of particles and the total error reduction (TER) criterion. It can be observed that the results of the numerical simulation are in agreement with the literature and that the proposed monitoring scheme was able to satisfactorily estimate the process variables and the disturbance.
Filtro de partículas aceleração-reponderação em um problema referência da engenharia química
(Universidade Federal do Espírito Santo, 2017-02-13) Hoffmann, Rayani Xavier; Dutra, Julio Cesar Sampaio; Silva, Wellington Betencurte da; Vieira, Fabrício Thiengo; Costa, Jose Mir Justino da
Due to the constant computational advances, as well as the development of efficient methods for solving nonlinear problems, it has become interesting the use on-line estimation on nonlinear chemical processes. In this context, the search for more faster and robust methods have become a challenge for researchers, for allows the accomplishment of real-time estimates of unmeasured or infrequently-measured variables, states variables and unknown or time-variant model parameters. Therefore, state estimation aims to use the information available through the process model and the measurements to obtain estimates of system states. This information can be used for monitoring, optimization and process control. For these reasons, the present work is aimed the application the Sampling Importance Reasampling (SIR) and MoveReweighting (AR) filters to the state estimation in an oil reservoir problem and the van der Vusse benchmark. For this, the various estimation methods are discussed, focusing on the particle filters. Next, the two cases proposed in this work were simulated for the application of particle filter algorithms. The results for both filters were satisfactory, but the AR filter obtained better performance. This methodology shows the benets when using a small number of particles and the move-reweighting approach can be promising to attenuate the asymmetry in the distribution of the particle weights, thus obtaining better results for online Bayesian inference and avoiding the need to use the resampling, which is a SIR filter problem.
Obtenção de ésteres metílicos utilizando dolomita como catalisador heterogêneo na reação de transesterificação
(Universidade Federal do Espírito Santo, 2017-02-14) Chiba, Marlene Leiko; Barañano, Audrei Giménez; Pinheiro, Iara Rebouças; Guimarães, Damaris
Climate change and environmental awareness of society have favored research into environmentally sustainable products and processes. Biodiesel is a fuel derived from renewable sources, such as vegetable oils and animal fats, which can partially or completely replace petroleum diesel. Conventionally, biodiesel is produced by homogeneous alkaline transesterification reaction, but studies have been carried out for the use of heterogeneous catalysts, which have advantages such as the reduction of effluent residues and the possibility of reuse of the catalyst. Dolomite is a limestone, an abundant material in nature and low cost, with industrial application in several areas. Recently, dolomite has been studied for use as a heterogeneous catalyst in biodiesel production. In the present study, a dolomite from a region of Cachoeiro de Itapemirim - ES was investigated for use as a heterogeneous catalyst in biodiesel production. The calcination of this dolomite at 900 °C for 2 hours resulted in materials with important characteristics, which were investigated by chemical analysis, XRD, TGA / DTG and SEM. These qualities ensured good catalysis of the reaction of transesterification of cottonseed oil with methanol in amount of 2% or 3% by weight of catalyst. It was also possible to reuse them for two more cycles. From the reactions resulted products with high concentrations of methyl esters of approximately 98% FAME, with methyl linoleate and methyl palmitate being the most expressive esters, and it was not necessary to use water in the purifications and other process steps.
Controle de um reator de polimerização de propeno utilizando filtro de partículas e rede neural
(Universidade Federal do Espírito Santo, 2017-02-15) Dias, Ana Carolina Spindola Rangel; Silva, Wellington Betencurte da; Dutra, Julio Cesar Sampaio; Fudym, Olivier; Mauri, Geraldo Regis; Guidolini, Icaro Pianca
Polymeric materials are present in several industrial sectors and in the society daily life, presenting advantages such as lower costs and higher durability. Polypropylene, obtained by the formation of propylene monomer long chains, is one of the most important olefins today, having a wide range of applications. Due to strong economic interest it arouses, there is a continuous search for improvements in its production process. Several methods for its obtaining it can be found by combining production technologies and catalysts. To ensure safety and achieve the operations objectives, it becomes necessary to insert structures for the process effective control. However, without a quality monitoring, this is not possible. In actual polymerization plants, the measuring devices are subject to uncertainties and are not always available; or the equipment does not exist or its purchase/maintenance cost makes its use unfeasible. Thus, this work proposes a virtual sensor scheme based on particle filter (PF) and artificial neural network (ANN), which is applied to a simulated propylene polymerization reactor. This structure allows the uncertainty reduction and the latent variables observation by means of PF. In turn, the ANN detects the polypropylene final properties from the improved data. The concern was to provide controllers with more complete and improved information. The results showed that the virtual sensor allowed improvements in process control, providing accurate estimates and consistent action time with industrial sampling intervals, which highlights its potential for practical application.
Controle preditivo baseado em modelo com estimação de estados restrita para controle e monitoramento de processos não lineares
(Universidade Federal do Espírito Santo, 2017-02-15) Carvalho, Romero Florentino de; Silva, Wellington Betencurte da; Dutra, Julio Cesar Sampaio; Vieira, Fabrício Thiengo; Fudym, Olivier
The present master degree work discussed about monitoring and control problem with a stochastic approach based in particle filter with application in typical problems of Chemical Engineering, which mostly, are nonlinear and have uncertainty non necessarily Gaussian. The chemical process control is of paramount importance in order to guarantee the quality and safety needs, beyond economic and operational viability. However, many of the variables linked to these objectives are not online measurement or present significant uncertainties. For this, is necessary consider estimation tools for the enable online control. In this sense, the present dissertation investigated a stochastic approach for the model predictive control (MPC), in which the MPC scheme is combined with particle filter (PF), which is a Monte Carlo sequential estimation tools type for nonlinear systems and non-Gaussian uncertainties. This proposal also considers optimizations methods to the particles projection that violates the physical or operational constraints, in a viable region, originating the scheme with initials CPF-MPC. This proposal extends results from previous work by including constraints in the process output variables. This scheme was applied to two case studies: non-isothermal CSTR reactor with simple first order reaction and CSTR with van der Vusse kinetics. Finally, the PF-MPC scheme was applied in a run-of-mine ore milling circuit and compared to a PI control. The CPFMPC results show a good and satisfactory performance to meet the control objectives, guaranteeing a relatively low computational time, reduction of the offset and process disturbance.
Produção de biodiesel de óleo de algodão utilizando catalisador heterogêneo sintetizado a partir da casca de ovo
(Universidade Federal do Espírito Santo, 2017-02-20) Castro, Luciene da Silva; Barañano, Audrei Giménez; Pinheiro, Christiano Jorge Gomes; Guimarães, Damaris
The search for alternative sources to fossil fuels due to dwindling oil reserves, increasing energy demand and reducing the environmental impact, emerged biodiesel, a biofuel with low toxicity and biodegradable. The synthesis of biodiesel is usually carried out using the transesterification method, which can use both homogeneous catalysts and heterogeneous catalysts to accelerate the reaction. Although the homogeneous catalysis is more used by the industries, it is necessary to perform several washes of the product and there is no recovery of the catalysts. Thus, the use of heterogeneous catalysts can overcome these difficulties, but it has a higher cost. In this paper sought to synthesize the CaO catalyst derived eggshell prepared at different temperatures of calcination for the production of cotton oil biodiesel. The catalysts were prepared from calcination and characterized by the Hammett method, X - ray diffraction (XRD), Thermogravimetry (TG) and Scanning Electron Microscopy (SEM). The catalytic activity was evaluated by the methyl transesterification reaction in triplicate for 3 h, using a 9: 1 molar ratio of methanol: oil, 3% catalyst (mass of catalyst/ oil) at 60 °C. The eggshell is rich in CaCO3, when subjected to heat treatment results in CaO, confirmed by the X - ray Diffraction. The high basicity of the catalysts was demonstrated by the Hammett method. The catalysts had a base strength of 9,8 = H_ < 12,2 and while the in nature shell eggshell had H_= 3.5. The calcination temperature exerted a strong influence on the heat treatment. The eggshell morphology was thermally modified. The catalysts exhibited good thermal stability. The transesterification reaction of the catalysts calcined at 800 °C, at 900 °C and at 1000 °C achieved an ester conversion of 97.83% and 97.23% and 98.08% respectively. Catalysts are promising for the production of biodiesel.
Estudo da molhabilidade de vidrado composto de resíduo de rochas ornamentais em cerâmica vermelha
(Universidade Federal do Espírito Santo, 2017-02-21) Carvalho, Romário Alves; Borges, Simone Pereira Taguchi; Borges Júnior, Luiz Antônio; Guimarães, Damares; Neves, Mirna Aparecida
The dimension stone industry generates large amounts of solid waste and an alternative to reduce this environmental liability is its use in the production of glazes. The objective of this work was to study the wettability of glaze made of dimension stone waste in red ceramic using the method of Sessile Drop. Six glaze compositions were prepared containing 49 to 77% of residue. The glaze was pressed with dimensions of 3mm x 3mm x 3mm and placed on a sintered red ceramic plate, and both were heated to fusion of the glaze up to temperature of 1100ºC. The variation of the contact angle was measured as a function of temperature, and the tests were repeated in specific isotherms to evaluate the kinetics of transformation. The contact angles from 1100°C change between 9 – 98° depending on the composition, indicating some glaze wet the surface of the ceramic satisfactorily while others do not spread, and therefore would not be indicated as composition for coating ceramic. The interface between the glaze and red ceramic showed physical interaction, indicating no reaction layer between the constituents.
Utilização de resíduo de rochas ornamentais para produção de cerâmica de revestimento
(Universidade Federal do Espírito Santo, 2017-02-21) Oliveira, Gabrielly Sandrine de; Borges, Simone Pereira Taguchi; Borges Junior, Luiz Antônio; Barañano, Audrei Giménez; Guimarães, Damaris
Brazil is among the main producers of natural stones. The extraction and processing of granites and marbles generates an enormous quantity of fine waste, from their extraction to the polishing. In this work, the dimension stones waste of diamond multi-wire machine was used in the engobe and glaze for application as a coating ceramic, because it has similar composition and granulometry to clay (basic constituent of these ceramics). After chemical characterization of the dimension stones waste and clay, some additives (fluxes, dyes and stabilizers) were mixed with the waste, and the engobe and enamels were prepared in different proportions. These compositions were tested to coating the ceramics with 30 mm X 30 mm X 5 mm, in the single firing and double firing processing, aiming to obtain more uniform surface and better technological properties. The single firing presented better surface results, being thus reproduced in the base ceramics with 100 mm x 100 mm x 5 mm. These ceramics were analyzed for relative density, shrinkage, water absorption, chemical attack resistance, and abrasion resistance, in according to NBR ABNT 13818 standard. The ceramics after sintering showed some cracks and relative density of approximately 77.8%. The double firing ceramics presented 5.14 ± 0.44% of linear retraction, and the single firing ceramics presented 4.35 ± 0.44%, values close to the literature. The samples were classified as “Class A” for the chemical attack tests, considered as excellent resistance. It can be concluded with wear test that the ceramic coating produced is indicated for residences or areas where it is usually walked with slippers or bare feet, and this ceramic is classified as PEI 1.
Simulação, controle e avaliação das configurações de troca térmica no processo de desidratação de etanol em reator de leito fixo
(Universidade Federal do Espírito Santo, 2017-02-22) Miranda, Hiago Vieira de; Dutra, Julio Cesar Sampaio; Vieira, Fabrício Thiengo; Guidolini, Icaro Pianca; Silva, Wellington Betencurte da
Ethylene is one of the most used monomers in the formation of petrochemicals. Due to the oil crisis in the 1970s, the expansion of new ways of obtaining ethylene was necessary, and processes previously little explored industrially began to be studied, in particular the process of catalytic dehydration of ethanol in fixed bed reactors. The process has major advantage in environmental matters, especially in the reduction of gas emissions that are responsible for the greenhouse effect, as opposed to more conventional processes, such as the cracking of naphtha. For processes in fixed bed reactors, the need to promote heat transfer properly can be a challenge, since a deficiency in the temperature regulation can lead to serious operating problems, such as termination of the reaction, low conversions or favoring secondary reactions. In this context, this work has as objectives the simulation of a fixed bed reactor model for ethanol dehydration reaction to ethylene, the verification of the effect of thermal fluid settings (co-current and countercurrent) and the implementation of a strategy of control for the reactor temperature. The countercurrent configuration provided higher conversion of ethanol and ethylene production under the evaluated operational conditions. The results of the simulations are in accordance with the literature. The temperature control at the cold spot of the reactor proved effective in reducing the effects generated by disturbances in the heating fluid feed temperature. Moreover, the PI controller also showed quick and smooth response to set point changes.
Síntese e caracterização de nanopartículas de Cu-ZnO e sua utilização no revestimento de superfícies de titânio por deposição eletroforética
(Universidade Federal do Espírito Santo, 2017-07-05) Gênier, Francielli Silva; Brito, Gilberto Augusto de Oliveira; Pinheiro, Christiano Jorge Gomes; Barañano, Audrei Gimenez; Guimarães, Damaris
The majority of metallic implant failures is due to body rejection to the material’s surface and to postoperative infections. Therefore, preventing bacterial growth on these materials and simultaneously contributing to their body adaptation are the main goals of recent researches on nanomedicine. As a way to reach these objectives, coating metallic prosthesis with nanoparticles represents a viable alternative to traditional treatment methods such as antibiotic administration, whose efficacy decreases as antibiotic-resistant strains of bacteria rise. The present work presentes the use of cooper doped zinc oxide nanoparticles (Cu-ZnO) to coat titanium surfaces, a commonly used material in medical devices, by electrophoretic deposition. These nanoparticles were chosen due their antibacterial characteristics, as presented on recent publications. Through microscopy (SEM and TEM), spectroscopy (EDS), and X-ray diffraction (XRD), the format and composition of the nanoparticles was confirmed as well as their crystallite size (228.24 nm) and lattice parameters. This material was suspended and deposited by electrophoresis on titanium plates for 1 minute under voltages between 100 and 180 V in order to obtain the best deposition condition, which was 160 V. The pH and conductivity of the suspension was also evaluated before and after the EPD. The EDS results confirmed the presence of the nanomaterial in the deposit. SEM images confirmed the increased surface roughness after electrophoretic deposition. Hence, this work’s goal was to explore a new potencial coatings process for artificial implants, in the way of contributing to the nanotechnology research field and its applications on medicine.
Produção de cerâmica de revestimento utilizando resíduos de rochas ornamentais provenientes do tear de fio diamantado
(Universidade Federal do Espírito Santo, 2017-07-25) Gomes, Tiago Marvila; Neves, Mirna Aparecida; Borges, Simone Pereira Taguchi; Borges Junior, Luiz Antônio; Guimarães, Damaris
Brazil is one of the largest producers of dimension stones in the world. Besides the economic advantages brought by the sector, there is also the generation of significant amount of fine solid wastes. The composition of these wastes shows the possibility of using them in several products, such as in manufacture of ceramic coating. The aim of this work was to use dimension stone waste from the diamond wire loom for production of ceramic coating. Compositions were prepared containing 40%, 50% and 60% of waste in the ceramic base, which were characterized regarding to the crystalline phase, particle size distribution and plasticity. Ceramic plates were sintered at 1100 °C and analyzed concerning to density, linear shrinkage and water absorption. Glazes were prepared with 40, 45 e 50 % of waste. Using these glazes and the base ceramic, ceramic coating were prepared and analyzed visually regarding to adhesiveness and chemical attack. Wettability test was carried out using the Sessile Drop method, that evolve the fusion of glazed proof bodies with 3 mm x 3 mm x 3 mm on sintered red ceramic with 30 mm x 30 mm x 5 mm. The contact angle was measured during fusion of the glazed material and the results were treated through factorial 22 analysis. The results indicate that the studied compositions have potential for industrial applications, presenting water absorption values close to 10%, contact angles - of the glaze in the base ceramic - smaller than 45° and a good adherence of the ceramic coating.
Catalisador ternário de PtRhSn0² disperso em carbono aplicado na reação de eletro-oxidação de glicerol
(Universidade Federal do Espírito Santo, 2017-09-06) Junco, Gustavo Garcia; Profeti, Demetriu; Profeti, Luciene Paula Roberto; Pinheiro, Christiano Jorge Gomes; Altoé, Mário Alberto Simonato
Currently, there is extensive discussion about energy issues, and due to the great apprehension related to the pollution generated by the use of fossil fuels and their probable scarcity, it is interesting to develop methods capable of supplying energy from renewable sources. Several research groups aim to develop fuel cells (FC’s) that operate with hydrogen or alcohols as fuel. However, a catalyst for direct alcohol fuel cell (DAFC) with high catalytic efficiency, tolerant to COads species poisoning and low cost was not found yet. In this work, PtRhSnO2/C electrocatalysts were developed and the results of electrochemical characterization using cyclic voltammetry (VC) showed that this catalyst has a profile similar to the polycrystalline platinum catalyst. These tests also allowed to identify the greater stability of PtRhSnO2/C in alkaline medium. The experiments performed by CV and chronoamperometry (CA) showed that the PtRhSnO2/C electrodes without thermal treatment (TT) and with TT had good catalytic activity for the electrooxidation of glycerol 0.5 mol L -1, since they demonstrated superior results to those obtained by the commercial platinum electrode (Pt/C 30% of E-TEK). It is important to note that the catalyst treated at 500 °C showed the best results in the tests performed by CV and CA. Also in this work, it was observed that the activation energy of the PtRhSnO2/C catalyst without TT decreases with the increase of temperature during the electrooxidation of glycerol. By means of the kinetic study, it was verified that PtRhSnO2/C without TT has less activation energy when compared to Pt/C 30% of E- TEK.
Gerenciamento de reservatório de petróleo baseado em controle preditivo não linear por meio de filtro de partículas
(Universidade Federal do Espírito Santo, 2018-02-23) Fortunato, Társis Baia; Dutra, Julio Cesar Sampaio; Silva, Wellington Betencurte da; Mauri, Geraldo Regis; Costa, José Mir Justino da
Energy is one of humanity's greatest needs and this need continues highly depends on the production of oil and gas. In this sense, the production systems of oil needs advances continuously. Currently, two techniques that make up the main trends of the oil industry and contribute to the advancement of production systems are model predictive control (MPC) and state estimation techniques. The production systems have characteristics of non-linearities that too are seen in the mathematical models that reproduce their behaviors. However, MPC is a mature technique only for linear models, and its application to nonlinear processes is conditioned to simplifying hypotheses. Its Nonlinear Model Predictive Control (NMPC) variant that uses nonlinear models has been indicated for use in the control of production systems, since it does not assume simplifying hypotheses. The challenges of NMPC lie in solving the problem of model-based optimization that integrates its methodology and also in the treatment of uncertainties. Thus, it has been common to associate NMPC with state estimation. However, even though there are several estimation techniques available, there are few that deal well with non-linear models. Thus, this dissertation proposes a methodology of control of the production system considering the step of secondary waterflooding recovery with a NMPC associated with state estimation. To the challenge in the optimization stage is applied a methodology that reformulates the optimization problem as a filtering problem and the optimum is estimated with the Particle Filter (PF), which in this task is renamed to Particle Filter Optimization (PFO). In the process of state estimation, a Particle Filter is applied which makes no simplifying hypothesis in relation to non-Gaussian uncertainties. The simulations required during the application of the two techniques will be obtained with the model describing the two-phase oil-water immiscible flow and the Finite Volumes method in its Two Point Flux Approximation variant. The results showed that the PFO maintained the production at the set point and that the estimation of the PF states was satisfactory, since the monitoring results did not show degeneration or impoverishment in the PF sampling and the results regarding the uncertainty treatment showed that the PF was able to reduce the uncertainty in the estimated saturation.
Estimação de parâmetros e estados via filtros Bayesianos em um processo de adsorção de SO_4^(-2) em resinas de troca iônica.
(Universidade Federal do Espírito Santo, 2018-02-23) Carvalho, Rhynara Niandra Silva de; Dutra, Julio Cesar Sampaio; Guimarães, Damaris; Silva, Wellington Betencurte da; Pinheiro, Christiano Jorge Gomes; Costa, José Mir Justino da
In the adsorption processes in fixed bed columns, which is very applied for the treatment of effluents, the measurements obtained at the end of the column allow to identify the efficiency of the process, but are accompanied by noise from measuring equipment. Since such systems are considered to be dynamic, therefore, the realtime monitoring of this process becomes a major challenge for the industry in order to providing a more accurate analysis of the process. Thus, the present work demonstrates the efficiency of the particle filter known as Sampling Importance Resampling (SIR) as a fast and robust tool for estimation and monitoring in a problem of sulfate ions (SO4 -2 ) removal in a fixed bed adsorption column. The fixed bed model and the mass transfer rate model were used to represent the whole process and experimental measures were used to validate the methodology used. Particle filter performance was evaluated through Root Mean Square Error (RMS) and Mean Absolute Deviation (MAD) analysis, as well as computational time verification. It was observed that the generated particles did not show degeneration by means of the verification of effective sample size (Neff) and the SIR filter presented better performance in the estimation when a higher value was used for the number of particles (Np) and for the deviation of the model of evolution (sm). In addition, flow estimation was of great importance for the filter to be able to make reliable estimates. In the analysis of the isotherms, the choice did not influence the estimation of the states. It was observed satisfactory results were observed and with remarkable applicability, once the use of the SIR filter has not yet been used to this type of process in the literature.
Eletrocatalisadores de platina promovidos com NiO aplicados na reação de oxidação de biocombustíveis.
(Universidade Federal do Espírito Santo, 2018-02-26) Moraes, Maurício Carlos; Pinheiro, Christiano Jorge Gomes; Profeti, Demetrius; Profeti, Luciene Paula Roberto; Guimarães, Damaris; Brito, Gilberto Augusto de Oliveira
Renewable energy is key to supplying new technologies, and a promising alternative to generate clean energy would be the fuel cell (CF), which produces electricity with reduction of pollutants, and with the use of biomass fuels, it becomes a sustainable source of energy. However, it is necessary to minimize the cost of production and to facilitate the supply of CFs to enable the large-scale application. In this context, catalysts composed of Pt and NiO were prepared, which were characterized by X-ray Diffraction, Dispersive Energy Spectroscopy and Scanning Electron Microscopy. The catalysts had a cracked-mud look, homogeneous distribution on the surface and concentrations close to the nominal ones. A direct relationship between crystallite size and Pt concentration was also observed. In addition, there was no alloying between Ni and Pt, since no changes were detected in platinum network parameters (cfc). The characterization of the electrocatalytic behavior of glycerol oxidation in PtxNi(1-x)Oy/Ti electrodes was investigated in alkaline medium. The catalysts were prepared by thermal decomposition of polymer precursors in different metal compositions with high electrochemical surface area. The results of cyclic voltammetry and chronoamperometry showed that glycerol oxidation current densities for mixed electrodes were higher than those obtained for electrodes containing only Pt at low potential values. In addition, the change in the onset potential of glycerol oxidation towards less positive values was also recorded, showing a facilitated oxidation with these materials compared to Pt. The electrodes that stand out are Pt0.8Ni0.2Oy/Ti and Pt0.9Ni0.1Oy/Ti because they have the highest electroactivity and the highest efficiency, respectively.
Estudo da adição de lítio a nanocatalisadores de óxido de cálcio para a produção de biodiesel
(Universidade Federal do Espírito Santo, 2018-02-27) Soares, Thaís Machado; Pinheiro, Christiano Jorge Gomes; Barañano, Audrei Giménez; Guimarães, Damaris; Brito, Gilberto Augusto de Oliveira
In view of the environmental impacts caused by primary energy sources, federal agencies around the world are increasingly seeking to institute research aimed at new sources of energy from renewable natural resources. In this regard, we highlight biodiesel, created to replace diesel oil derived from petroleum. Industrially, the production of this biofuel is catalyzed by homogeneous catalysts, which end up giving certain limitations to the process. Thus, heterogeneous catalysis is an alternative that has been evaluated, being that calcium oxide (CaO) is one of the solid catalysts that has been highlighting, due to its high activity and low cost. However, CaO has presented leaching problems. In this context, the objective of this study was to present a diagnosis related to the addition of lithium in calcium oxide nanocatalysts, synthesized by the wet impregnation method and thermal decomposition, in order to evaluate which technical is more efficient to obtain a material with a greater stability and selectivity to serve as a heterogeneous catalyst in transesterification reactions of soybean oil via the methyl route. Using thermogravimetric (TGA), X - ray diffraction (XRD), spectroscopy (FTIR) and microscopy (SEM) and (TEM) techniques, for verification to the format and the elements present as well as the mean crystallite and the network parameters of the nanocatalysts. By means of the spectroscopy technique (1H NMR), it was possible to verify that the addition of lithium in the CaO nanocatalyst increased catalytic activity and selectivity in biodiesel. In addition, the techniques used for the synthesis of the nanoparticles provided greater stability to the material. For, the conversion of products into biodiesel was higher than 87% in the third reaction cycle.
Preparação e caracterização de hidrogel com nanopartícula de cério, Calendula officinalis ou Bixa orellana L., como potenciais curativos de feridas crônicas
(Universidade Federal do Espírito Santo, 2018-02-27) Rezende, Talita Colombi; Paula, Heberth de; Pinheiro, Christiano Jorge Gomes; Pinheiro, Iara Rebouças; Moraes, Pedro Alves Bezerra; Carreira, Lilian Gasparelli
The development of new technologies and discovery of new resources has a great advance the treatment of wounds, improving the patients life quality. Thus, throughout the world there has been a growing interest in using the hydrogel for applications as wound dressings, since they favor pain relief. In addition, hydrogels can also be applied as matrices to the principle controlled release system. The aim of this work was to incorporate the cerium nanoparticle, the Calendula officinalis and the Bixa orellana L. as active in hydrogel membranes in order to evaluate the efficiency in the healing. The cerium nanoparticle, the Calendula officinalis and the Bixa orellana L. are actives which are excellent antioxidant and antibacterial anti-inflammatory properties. The study of mechanical, physical-chemical properties and “in vivo” biocompatibility of poly (vinylpyrrolidone) (PVP) hydrogel membranes obtained by gamma cross-linking was carried out. The membranes prepared in this study are characterized by swelling, gel-fraction, traction test, scanning electron microscopy, X-ray diffraction, transmission electron microscopy and atomic force microscopy. A synthesized hydrogel matrix proved to be a great base for receiving the active purposes. The "in vivo" assays showed a promising application to apply in the cicatrization process, deposited directly in the dissemination of the lesions, and the hydrogels with Calendula officinalis presented a better contribution to the size reduction of the fertilizer.

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