Mestrado em Energia

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Uma metodologia para reconfiguração de redes inteligentes
(Universidade Federal do Espírito Santo, 2013-06-14) Bento, Fabio Ricardo Oliveira; Celeste, Wanderley Cardoso; Silva, Roney Pignaton da; Pereira, Flavio Garcia
Investigação do leito de jorro como reator em potencial de pirólise de partículas cartonadas
(Universidade Federal do Espírito Santo, 2013-08-16) Marques, Ícaro Ibrahim Dias de Rodrigues; Bacelos, Marcelo Silveira; Arrieche, Leonardo da Silva; Lira, Taisa Shimosakai de; Neves, Fernando Luiz
Currently, pyrolysis has received special attention because of its potential application in areas that constitute challenges of the contemporary world, among which stand out the need for renewable energy production and the issue of solid waste management. Among the modern solid wastes, the post-consumer carton packaging highlights due to the high value-added of the primary products (aluminum and paraffin, obtained from its pyrolysis), and coal presenting high calorific value that can be used as fuel to increase the energy efficiency of the process. For presenting good gas-solid contact, high rates of heat and mass transfer and low particle segregation, the conical spouted bed arises as an efficient alternative for the pyrolysis of carton packaging. In this context, in an attempt to use conical spouted beds (CSBs) as a pyrolysis reactor, this present research aims at analyzing the carton particles fluid dynamics in CSBs. To achieve this goal, the fluid dynamics behavior of carton disks mixtures with particles of different specific masses, namely, polyethylene and sand, was investigated. Experimental data of bed pressure drop as a function of air velocity were obtained and analyzed. The operating conditions employed in the conical spouted bed were simulated by CFD technique. For beds composed of polyethylene and carton disks in a range of mass proportion of 20 and 50% carton disk, the analyses established in this research show that the spouting regime is established. For beds comprise mixtures with 5 and 10% carton disk (in mass) stable spouting regime was achieved. At the set of operating conditions, the Eulerian Granular Multiphase Model applied with Syamlal-O‟Brien drag model can qualitatively predict the typical fluid dynamics behavior of a conical spouted bed operating with mixtures of non-spherical particles. An analysis of reuse of the carton packaging via pyrolysis, from the energy and environmental points of view, shows that a large amount of bauxite and energy can be saved due to aluminum which is recovered in the process.
Tratamento de água oleosa por eletrofloculação
(Universidade Federal do Espírito Santo, 2013-08-19) Gobbi, Lorena Cristina Abrahão; Porto, Paulo Sérgio da Silva; Rocha, Sandra Mara Santana; Lisbôa, Antonio Carlos Luz
An electroflocculation technique using aluminum electrodes to separate oil from synthetic oily water with an average concentration of 200 mg/L of crude oil was used. To evaluate the viability of the technique, the percentage of chemical oxygen demand (COD) and oil and grease content removed, the concentration of total solids, volatile and stable, electrical conductivity, pH, total alkalinity and acidity of the oily effluent samples during treatment were found. We also estimated the operational energy cost for the application of the technique. In this work we built a reactor electrolyte bench with capacity of 4 liters. In its interior, aluminum electrodes were connected in parallel arrangement to a polarity inversor plate and to an external power source. Preliminary tests were carried out to find the best area of electrode to volume of effluent ratio for the COD removal. From these tests, we used the largest electrode (13.0 X 6.5 X 0.2 cm) because it presented the best condition (about 90%). The results show an increase in pH and alkalinity, reduction in acidity, while electric conductivity and concentration of solids showed little deviation during the treatment. The average percent removal was 96% of oil and grease content, while the COD was 81%. The effluent resulting from the electrolysis was qualitatively transparent to the visible eye. Statistical analysis for electrical conductivity and total solids showed that they depend significantly on the concentration of electrolyte (NaCl) in the medium. For COD and oil and grease content, only the distance between the electrodes was a significant factor. The variation of initial pH was not significant in relation to the variables. As for the energy cost, the electroflocculation costs on average R$ 0.32 / m3 , the electrode consumption was 0.60 g and the operating cost R$ 3.41 / m3 . These results show that it is possible to use the technique in oily water treatment due to better technical and economic values, compared with the literature.
Pirólise de resíduos de embalagens cartonadas e seus componentes puros : uma avaliação cinética
(Universidade Federal do Espírito Santo, 2013-09-06) Alvarenga, Larissa Machado; Lira, Taisa Shimosakai de; Arrieche, Leonardo da Silva; Barrozo, Marcos Antonio de Souza; Bacelos, Marcelo Silveira
Many processes have been used for recycling of carton packaging wastes. The pyrolysis highlights as a promising technology to be used for recovering the aluminum from polyethylene and generating products with high heating value. In this research, a study on pyrolysis reactions of carton packaging wastes and its pure components was performed in order to estimate the kinetic parameters of these reactions. For this, dynamic and isothermal thermogravimetric analyses were carried out and two different kinds of kinetic models were used: the isoconversional and Independent Parallel Reactions (IPR). Isoconversional models allowed to calculate the overall activation energy of the material pyrolysis reaction, in according to their conversions. The activation energy values obtained with Ozawa, KAS and Starink models for carton packaging pyrolysis were similar (168.30, 166.54 and 166.78 kJ.mol-1), as well as the results found for polyethylene (137.41, 132.49, 132.98 kJ.mol-1) and cardboard (155.66, 153.46, 153.69 kJ.mol-1). Nevertheless, the Kissinger method the method of Kissinger estimated lower values of activation energy for carton packaging (121.42 kJ.mol-1) and cardboard (144.89 kJ.mol-1), and a higher value for polyethylene activation energy (155.15 kJ.mol-1). The IPR model, in turn, allowed the calculation of kinetic parameters of each one of the carton packaging and paperboard subcomponents. The estimated values for the kinetic parameters of the material subcomponents were within the range of values found in the literature. The mass loss of materials simulated with the RPI model showed a good fit to the experimental data obtained by thermogravimetry, presenting deviation values in the same order of magnitude as those found in other literature studies. It was also performed a parametric sensitivity analysis of IPR model, that shown that the activation energy affected the total conversion of the material more strongly than the pre-exponential factor. In general, this work contributed to the quality evaluation of the kinetic models adjustment and for the calculation of the kinetic parameters of material pyrolysis.
Modelagem e simulação termodinâmica da precipitação de calcita em condições de poço
(Universidade Federal do Espírito Santo, 2013-09-18) Cosmo, Rafael de Paula; Pereira, Fábio de Assis Ressel; Siqueira, Renato do Nascimento; Ribeiro, Daniel da Cunha; Romero, Oldrich Joel
Oil will still be the matrix of higher energy demand in Brazil and around the world for decades. Easily accessible oil deposits are increasingly scarce, and therefore, more challenging reserves will require innovative solutions and technologies. Among the challenges imposed to the process, are those related to flow assurance, especially saline fouling of carbonate origin, noticeably calcite. Several phenomena occur for effectivation of the fouling, such as nucleation, crystal growth, particle agglomeration, transport and surface adhesion, among others. The forecast of fouling only will represent the reality if all phenomena are accurately described. In this sense we pursued to model thermodynamically, for well conditions, the initial stage of fouling, which is the nucleation of crystals from solution. One of the results obtained was an explicit equation, as a function of pressure and temperature, of the equilibrium constant for the reaction which is expected to occur under the conditions investigated: CaCO3(s) + H2O(l) + CO2(aq)  Ca2+ (aq) + 2 HCO3 – (aq). In order to quantify the content of calcite likely to precipitate from the solution, a methodology was developed not only to measure the mass precipitated, but also to distinguish the origin factor of precipitation. As a result it was verified that the changes in the thermodynamic conditions little affect the calcite precipitation, but greatly affect the solubility of the carbon dioxide, and this really influences in a preponderant manner the crystallization of the carbonate salts, because it contributes to 60% to 90% of the total content precipitated.
Avaliação da eficiência do ultrassom no processo de separação de fases em água produzida e em emulsões sintéticas do tipo O/A
(Universidade Federal do Espírito Santo, 2014-02-20) Ronchi, Renata Peterle; Melo, Breno Nonato de; Santos, Maria de Fátima Pereira dos; Flores, Érico Marlon de Moraes
A major problem in the petroleum industries is related to the development of effective technologies for the wastewater treatment derived from the primary processing stage, which presents stable emulsions of oil in water (O/W). A methodology for the synthesis of O/W emulsions is tried. It runs a few tests with ultrasound equipment in order to evaluate the ability of this technique in phase separation and the reduction in the content of Oils and Grease (TOG). The most stable emulsion obtained was the 1% (w/w) O/W emulsion, without any addition of compounds. That emulsion was then employed in the tests developed with ultrasonic equipment with frequencies of 25, 35, 45 and 130 kHz at temperatures of 25 and 60 °C. The 20-minute exposure time and presence or absence of Raschig rings were assessed too. The use of ultrasound applied in synthetic emulsion appeared as a promising technique. It could remove about 70% of the xxvii oil content in the oil by applying frequencies of 35, 45 and 130 kHz at 60 °C with Raschig rings. The conditions of the best results were also selected for the study of produced water derived from the field A, but this time with shorter exposure time to ultrasound with more concentrated synthetic emulsions and colloidal particles, utilizing further materials like copper, PVC®, PTFE®, steel and polypropylene. Good results were obtained for 15-minute exposure time to ultrasound and denser materials such as copper and steel. TOG could reach values of up to 80% of reduction. The results for the other synthetic emulsions and produced water were worse than the 1 % (w/w) O/W emulsion, without acid, base or silica. Therefore, one can conclude this as an efficient laboratory method for oil/water phase separation and still fits a simple physical separation process with low cost, low dwell time and no need of chemical products.
Rotas de aproveitamento tecnológico de resíduo orgânico agrícola : casca de coco, casca de cacau e casca de café : destinadas à geração de energia
(Universidade Federal do Espírito Santo, 2014-03-06) Batista, Renato Rocha; Chaves, Gisele de Lorena Diniz; Arrieche, Leonardo da Silva; Bacelos, Marcelo Silveira; Lira, Taisa Shimosakai de; Sartori, Dermeval José Mazzini
The availability of agricultural waste for bioenergy generation come to propose the recent interest by agroenergy sector. For this goal, this dissertation show a bibliografic study for waste characterization of cocoa bark, coconut bark and coffee bark in according to bioenergy technologies: anaerobic digestion, pyrolisys and direct combustion. Its made analysis of technology route possibilities for transform the energy potencial from fruit waste composition in electric energy. The objective its towards the structural synthesis of chemical process by problem representation with process state trees. From the combination of elements of study: fruit waste, biomass processing technology and chemical conversion technologies; its proposed the possibilities of technology routes for elaborate the branches of state trees. The step of structural optimization its based in applied the heuristics method towards the syntesys problem. Thus, its selected the most promised technology route of energetic use of each waste. As a result, the anaerobic digestion in batch reactor was the better option for cocoa bark. For a coconut bark, the chemistry route more adequated was the direct combustion, realized in boiled fixed grid; and for a coffee bark, the thermochemical pyrolysis conversion preceded by pelletization compactation showed more promised. As contribution from this work of dissertation stands out the possibility of energetic valorization of fruit waste untill then considered useless for energetic sector. The problem representation by systematic of state trees and after applied solution by heuristics rules show the originality from this proposed work.
Particionador paralelo de grafos utilizando algoritmos heurísticos para aplicação em simuladores paralelos de reservatórios de petróleo
(Universidade Federal do Espírito Santo, 2014-03-14) Silva, Leonardo Rogério Binda da; Silva, Roney Pignaton da; Lorenzoni, Luciano Lessa; Celeste, Wanderley Cardoso
Oil is currently the most widely fuel used in the world. To obtain it to the greatest possible economic viability is a relentless pursuit of the producing companies. In this scenario, the numerical reservoir simulation using parallel computers with distributed memory (clusters) is emerging as an important tool. These application handle mashes of discrete points that represent the field of oil reservoir. An important step of the simulation using clusters is the partitioning of this mesh points so that each cluster process node can perform its calculations on a portion of this mesh. The domain meshes can be represented by graphs. Partitioning meshes then becomes a problem of graph partitioning. If the graph vertices number that represents the mesh is very high, serial partitioners can have performance problems. Graph partitioners using clusters appear as interesting alternatives in this situation, minimizing the time spent in partitioning. This research deals with the implementation of a parallel graph partitioner to be used in clusters based on partitioning heurists proposed and implemented serially by Bonatto (2010). The parallel partitioner has been developed using the Java programming language and MPJ Express messages passing library. Efficient abstract data types have been proposed and implemented in order to optimize the performance. The parallel graph partitioner performed the cutting of different graphs, obtaining, most of the time, smaller cuts than the ones found by serial partitioner of Bonatto (2010) and by programs such as METIS and CHACO. Improvements to the Bonatto (2010) serial partitioner have been proposed. Analysis of speedup and parallel efficiency have been performed to find out the gains of times abtained with the parallelization of the heuristics.
Uma abordagem heurística para o problema de roteamento de sondas de intervenção bi-objetivo
(Universidade Federal do Espírito Santo, 2014-08-18) Bissoli, Dayan de Castro; Chaves, Gisele de Lorena Diniz; Ribeiro, Glaydston Mattos; Lorenzoni, Luciano Lessa; Rosa, Rodrigo de Alvarenga; Silva, Roney Pignaton da
Throughout the productive life of oil wells, some interventions known as workovers are usually necessary. These repairs, are held by intervention rigs and are essential to maintain production or possibly improve it, these being scarce and expensive. Given a set of wells requiring maintenance and a heterogeneous fleet of rigs, each rig with a specific starting position, the Workover Rig Routing Problem (WRRP) consists in finding routes for the rigs so that the total loss of production of wells within a planning horizon is minimized. The route of a rig is considered feasible if it has the necessary equipment to carry out all the maintenance of associated wells and respect the stipulated planning horizon. In the literature, many authors have proposed models and solution methods for the WRRP mono-objective, i.e., trying to minimize just the total loss of production, not considering the rental of rigs. Therefore, this paper studies the WRRP bi-objective which minimizes both the total loss of production of the wells and the rental costs of rigs. We implemented an Adaptive Large Neighborhood Search metaheuristic for this problem, which was tested considering instances proposed in the literature as well as from new situations proposed in this paper, in order to approach the problem in real-life context. The results of this research show that although the minimization the total loss of production is an a very important objective, the variation of the rental cost of the probes and as oil prices affect in the definition process of routes.
Redução de falhas em haste polida : proposta de uma nova forma de fixação à unidade de bombeio
(Universidade Federal do Espírito Santo, 2014-08-29) Moura Júnior, Jerônimo de; Romero, Oldrich Joel; Silva, César Augusto Sodré da; Ribeiro, Daniel da Cunha
Sucker-Rod Pumping is the most used method of artificial lift in the world, and this is one of the most important motivators for studies aimed to reducing failures related to this method. Among these failures, it can mention the polished rod break, that is a component located at the top of the rod string, and it subjected to stress cycles. This failure interrupts the well production, causing financial losses and may even cause environmental damage and endanger the safety of people involved in this context. So, we want to answer the question: is it possible to increase the time between failures of the polished rod by changing your attachment to the carrier bar? Thus, this paper is developed a new method of attachment of the polished rod to the carrier bar, in order to reduce problems related to failures in the region of its attachment. To understand the issue, it was made an exploratory, descriptive and explanatory research, through a literature review related to the efforts that the polished rod is submitted during its operating cycle, the shape and type of the attachment device currently used and the recurrent failures caused this component. Through computer simulation, using SolidworksSimulation®, this study determined the geometries of system devices currently used, the operating conditions involved, analyzing the results of its strain and safety condition, besides having analyzed fatigue imposed to the polished rod in dynamic situation. From a proposal for a new method of attachment of the polished rod to the pumping unit, it was determined the geometries of the devices involved and also analyzed the dynamic and static forces imposed on them, in addition to conducting comparison, as regards the fatigue and life between the two forms of attachment. The results indicate that, theoretically, the new proposal has great potential for reducing crashes polished rod, indicating life to greater to 50 million cycles.
Análise do leito de jorro como sistema de contato para pirólise de compósito PEBD/AL
(Universidade Federal do Espírito Santo, 2014-09-11) Melo, Jardel Leno Zancanella; Bacelos, Marcelo Silveira; Ferreira, Maria do Carmo; Arrieche, Leonardo da Silva; Lira, Taisa Shimosakai de; Pereira, Fábio de Assis Ressel
In the last decade, several routes of waste cartons reusing have been proposed in the literature. Among other recovery processes, pyrolysis of carton residues has been highlighted due to make possible the manufacture of products with high added value, such as paraffin oils and aluminum bars. Recently, the spouted bed has been investigated as a promising reactor for pyrolysis of solids, due to its high rate of thermal exchange. However, in order to occur the pyrolysis appropriately is essential the study about the dynamics of air flow between solid residues in conical spouted bed. Thus, this research aims to analyze the flow of the LDPE/Al composite (in the form of pellets, ds = 2,58 mm) and mixtures of LDPE/Al composite and sand (ds = 2.58 mm) in a conical spouted bed. The experimental data of pressure drop are measured by a differential pressure transducer. These are assigned to an A/D interface, National Instruments. and processed on a computer by data acquisition program developed with Labview 10.0. The data of velocity of air are obtained by frequency inverter, which accompanies the experimental apparatus. The Eulerian model is used to describe the flow of air-solid in conical spouted bed. The equations of the model are addressed using the technique of computational fluid dynamics with the finite volume method, using a structured two-dimensional mesh. Among the tested turbulence models, the k-ɛ model dispersed seems to be appropriate to predict characteristic fluid dynamic behavior of the bed. The CFD simulations are adequate in this case study, underestimating the experimental values, where data for the minimum spouting velocity (Vmj), pressure drop of minimum spouting (ΔPmj) and maximum pressure drop in the bed (ΔPmax) have a maximum deviation of -13.5; -9.5 and -23, respectively. Analyzing the stability of the bed, to use mixtures with LDPE/Al composite mass fraction between 20 and 40% is recommended.
Quartzo como estabilizante contra a fotodegradação de polímeros transparentes de painéis solares fotovoltáicos
(Universidade Federal do Espírito Santo, 2014-09-19) Emmerich, Wilson Obéd; Proveti, José Rafael Cápua; Muniz, Eduardo Perini; Porto, Paulo Sérgio da Silva; Silva, Igor Alessandro
Plastic transparent materials exposed to solar light suffer photodegradation due to ultraviolet (UV) radiation. One particular case is the yellowing of the encapsulating polymeric material of solar panels with correspondent reduction in light transmittance to the silicon layer and loss in efficiency of the panel. In a recent work, Carvalho (2011), quartz particles were produced and submitted to gamma rays irradiation and they worked as stabilizer against photodegradation of a quartz + EVA compound. In the present research we tested other, lower cost, paths using quartz but without gamma rays irradiation. Only heat treatments and mowing were used. A new methodology was developed, including a quality factor to evaluate the adequacy of the samples to the protection of plastics against photodegradation. After heat treatments at temperatures ranging from ambient to 1100°C for 3 or 6 hours, the quartz samples were macerated in agate mortar or mowed in a spheres mill. The two kind of mowing reduced the average particle size. Mowing in a spheres mill also reduced crystalline grain size. Both effects, that is, reduction in grain and particle size, as well as the increase in quality factor, happen in the first minutes of mowing (15 min in the spheres mill) or maceration. Mowing for longer times do not change appreciatively the quality factor. The quality factors of our samples are similar or better than those from samples produced by Carvalho (2011) and that protected successfully polymeric films against photodegradation.
Estudo do escoamento laminar sólido-líquido em anular excêntrico empregando a técnica de dinâmica de fluidos computacional
(Universidade Federal do Espírito Santo, 2014-12-15) Facuri, Rafael Manache; Ribeiro, Daniel da Cunha; Pereira, Fabio de Assis Ressel; Siqueira, Renato do Nascimento; Romero, Oldrich Joel
Exploration techniques such as horizontal wells to increase production efficiency have been practiced but it brings a challenging scenario for the operation, which includes the transport of cuttings during the drilling operation. Several parameters affect the efficiency of the transport including mainly properties of the drilling fluid and the characteristics of the drilling system. Besides the wide range of variables, and their interactions, which affects this efficiency and makes this study difficult, the real conditions in which these variables are applied as high temperature and pressure, it makes the challenge even more complex, especially because these conditions are not always possible to be reproduced in experimental units. In this sense the multiphase flow phenomenon of carrying cuttings by the drilling fluid was modeled through the technique of CFD (Computational Fluid Dynamics). The computational model was based on the Eulerian Granular approach for simulating the solid-liquid multiphase flow in a laminar regime and the model was validated by the experimental data from Yu et al. (2007). With this model the fluid dynamics of a non-Newtonian fluid Bingham plastic was analyzed in a horizontal column with eccentricity of 13.74 mm (offset) studying the effects of the drilling fluid flow, the drilling pipe rotation and penetration rate in the efficiency of cuttings removal, using central composite design with 16 runs. The comparison of the experimental results of Yu et al. (2007) and the model showed good agreement with average deviations of |6.6%|. That said, it was possible to elucidate the order of magnitude of the effects of the variables on the cutting removal and the pressure drop, giving special attention for the maximizing effect of drilling pipe rotation on the hole cleaning efficiency and for the important effect of fluid flow on the pressure drop. However, the flow had insignificant effect on the cuttings concentration, showing that within the tested range of laminar flow, the hole cleaning efficiency is little affected by flow of the drilling fluid. The results of the numerical simulations agreed with the results found in the literature.
Estudo numérico da movimentação da válvula de pé do sistema de bombeio mecânico com hastes
(Universidade Federal do Espírito Santo, 2014-12-19) Nico Filho, Gelson Heraldo; Ribeiro, Daniel da Cunha; Romero, Oldrich Joel; Silva, César Augusto Sodré da; Pereira, Fabio de Assis Ressel
The downhole pump of artificial lift method sucker rod pumping is a component that has the highest number of failures when working with heavy oils, due to this fact, this work employs a numerical analysis of the fluid inside this equipment. The analysis focused primarily understanding the behavior of the standing valve, one of the most important components of the pump, and its influence on the flow inside the pump. The analysis parameters are fill rate of the shirt, Pressure Drop, difficulties in closing and predict the occurrence of pump off. The study uses a typical pump system geometry, which was built using Inventor ® 3D CAD the real 3D geometric conditions. The Ansys Fluent version 14.5 software was used to solve the coupled equation system of fluid flow and motion of the standing valve, considered rigid. The final computational model allowed to judge if the type of bottom pump chosen is adequate and predict the occurrence of pump off, in order to achieve a longer service life of the downhole pump and evaluate the best performance upon various operating conditions. As a final product, was obtained a tool for the analysis of standing valves pumps background in order to avoid premature failure.
Modelos computacionais ultrassônicos com ênfase na emulsão O/A
(Universidade Federal do Espírito Santo, 2015-02-24) Leão, Rodrigo Xavier de Almeida; Santos, Maria de Fátima Pereira dos; Bizzi, Cezar Augusto; Oliveira, Luiz Gabriel Souza de
This work proposes a study simulating the use of ultrasonic probes and ultrasound bath applied in emulsions produced by the oil industry, specifically, the emulsions of oil-in-water (o/w) found in produced water. The first part of the study consisted in an analytical solution of the Bessel equation in order to study the formation of the radial pattern of standing waves in a cylindrical container containing the o/w emulsion at low (24 kHz) and high (1.841 MHz) frequency, from an ultrasound transdutor located at the center of the container. The second part of the study consisted in the construction and application of a computer model capable of representing the displacement of the ultrasonic waves within an ultrasonic bath containing a container filled with an o/w emulsion, synthesized from petroleum with 13.1 ° API in the presence of materials. The analytical solution of the Bessel equation estimated frequency to 24 kHz ultrasonic probes, the first three stationary vibration modes occur respectively in radius containers 34.45; 54.01 and 73.60 cm. When the simulation was applied to ultrasonic probes frequency 1.841 MHz estimated that three stationary vibration modes occur respectively in containers radius 0.45; 0.70 and 0.96 cm. The results of the computer model simulating the displacement of the ultrasonic waves within an ultrasonic bath proved according to experimental results, permitting identification of the increased density of the acoustic field that occurs due to the presence of material within the emulsion as the main responsible for the high efficiency in the removal of this oil fraction in the emulsions under the action of ultrasonic fields of low frequency. Was estimated as a material is capable of increasing the density of the sound field compared to a container without the presence of materials, being: 1.47 to Teflon, 2.05 to PVC, 2.07 to polypropylene, 2.17 for aluminum, 2.87 to copper, 3.00 to nickel, 3.01 to brass, 3.09 to steel and 3.72 to lead. The area occupied by the material within the container proved responsible for the amount of energy retained therein. The influence of the variation of the area of the materials present in the emulsion was also assessed from the results of the developed model.
Logística reversa do óleo residual de fritura para produção de biodiesel do Distrito Municipal de Kampfumo-Cidade de Maputo
(Universidade Federal do Espírito Santo, 2015-03-17) Matavel, Nilza Isabel; Ribeiro, Glaydston Mattos; Chaves, Gisele de Lorena Diniz; Rosa, Rodrigo de Alvarenga; Meneguelo, Ana Paula
Waste frying oil (WFO) is a household waste, which causes a negative impact in social, economic and environmental level, when it is improperly discarded. The alternative of the improper disposal is the recycling, which enables the production of a range of profitable products, where biodiesel is highlighted. The use of WFO as a complementary input in Mozambican biodiesel production system, has the potential to strengthen, complement, and expand the development of this sector. The introduction of WFO, will add the value of the sector, and can benefit the rural electrification projects, reducing vulnerability to gastric diseases, pollution prevention, and reduction of diesel imports. In this context, this paper, present the projection of a reverse logistics network to enable the collection and transport of WFO, to ensure their adequate supply for reuse especially for the production of biodiesel in municipal district KaMpfumo. The links / bonds of the network proposed are the producer of WFO and the logistical facilities to enable the reverse process, the returns centers and pre-treatment centers. The mathematical model proposed, was based on a variant of p-Median problem for facilities location. The resolution method was Mixed Integer Linear Programming, implemented in C/C++, and tested with CPLEX. The model was powered by scenarios that evaluated the hypotheses proposed in the study. The scenarios analysis allow to evaluate the hypothesis proposals, estimating the current situation of the WFO collection, the elevation of this collection through population growth over the next years and through implementation of the legal framework proposed to impulse the biodiesel production. The results of modeling generated the opening of 12 returns centers and one pretreatment center for all scenarios. The results show that the collected volume of ORF is the main factor of varying costs of scenarios, and the operating costs and the transportation costs are those with the highest values in the reverse logistic proposed. This work contributes to the decision-making processes regarding the WFO management, and the diversification of raw material to biodiesel production in these country.
Comportamento reológico de emulsões do tipo água em óleo de petróleos pesados : estudo experimental e avaliação de correlações empíricas
(Universidade Federal do Espírito Santo, 2015-05-07) Ferraz, Ludian Anacleto; Pereira, Fábio de Assis Ressel; Castro, Eustaquio Vinicius Ribeiro de; Meneguelo, Ana Paula; Machado, André Luiz de Castro
In general, when the oil fields get older the amount of produced water increases. This increase tends to cause the undesirable situations, such as the production of stable emulsions with high viscosities that to be pumped require larger capacity equipment, besides, they demand more energy for processing. From the point of view of project design, another disadvantage is the uncertainty found in the thermo-hydraulic calculations of pipes due to the use of inadequate information in regard to the rheological properties of emulsions. Inadequate predictions can result in incorrect sizing of equipment with potential economic impacts. In this work, in order to evaluate some of the main empirical correlations, aimed at predicting viscosities of the water-in-oil emulsions (W/O) and present in two of the most prominent multiphase flow simulators (OLGA® , PIPESIM® ), were collected four (4) oil samples from oil wells from petroleum fields of the North Capixaba, with API degree between 13 and 23, and through Design of Experiments (DOE), the influence of the temperature, volume fraction of dispersed phase and shear rate on the relative viscosities of the emulsions were evaluted. The effect of volume fraction of the dispersed phase proved to be highly significant, while the effect of temperature and shear rate proved to be insignificant. By way of further testing was possible to compare empirical correlations proposed in the literature and conclude that the correlations Brinkman (1952), Vand (1948) and Pal and Rhodes (1989) showed satisfactory results for predicting the behavior of emulsions produced by heavy oil.
Pirólise do bagaço de laranja : análise cinética dos estágios de secagem e devolatização
(Universidade Federal do Espírito Santo, 2015-07-14) Benevides, Lorena Coelho; Lira, Taisa Shimosakai de; Schettino Junior, Miguel Angelo; Araújo, Jesuína Cássia Santiago de; Pinotti, Laura Marina
Brazil produces 1.4 million tons of orange juice, accounting for 50% of world production. It is estimated that 40-60% of the volume processed is considered tailings. An alternative use of residual biomass is their use for obtaining energy from the pyrolysis process. Understanding this process involves the study of the residual biomass degradation kinetics, transport phenomena, and the type, configuration, and optimal conditions of reactor operation. The aim of this work is the kinetic study of orange bagasse pyrolysis. With respect to thermogravimetric analysis, this was assessed in two stages: the first refers to the free water loss to 373 K (drying) and the second referring to the pyrolysis reactions (devolatilization). For the drying step, the semi-empirical models of drying were used in their non-isothermal forms. As for the devolatilization phase, they used the isoconversionais models and independent parallel reactions (RPI) reparametrized. For the first stage, the model that best describes the dynamic drying step was to Overhutz, obtaining average activation energy of 11,24 kJ/mol. As for the second stage, isoconversionais models showed activation energy between 104,94 and 417,27 kJ/mol. The reparametrized Independent Parallel Reactions model presented activation energy between 130,32 and 153,62 kJ/mol, 144,00 and 194,65 kJ/mol, 59,23 and 85,41 kJ/mol, 74,16 and 148,89 kJ/mol, and 163,95 and 184,23 kJ/mol for hemicellulose, cellulose, lignin, pectin, and component not known respectively. Fractions of subcomponents of orange bagasse were also estimated and is obtained approximate values of 21, 31, 17, 25 and 6% hemicellulose, cellulose, lignin, pectin and component x, respectively. In addition, it evaluated the convective drying kinetics bagasse, since it has a high initial moisture content, using the semi-empirical equations drying kinetics. The activation energy for convective kinetics of orange bagasse was 20,99 kJ/mol and the Overhultz model was the one best suited to the experimental data.
Desenvolvimento de método de extração-floculação por aplicação de ondas ultrassônicas em óleo lubrificante usado
(Universidade Federal do Espírito Santo, 2015-08-11) Souza, Felipe Oliveira; Vicente, Maristela de Araujo; Santos, Maria de Fátima Pereira dos; Bizzi, Cezar Augusto; Araujo, Jesuina Cassia Santiago de
This paper proposes an innovative process based on the use of ultrasonic waves (US) for the decontamination of used lubricating oils. The proposed system consisted of applying a sound field through a US bath where the contaminated used lube oil, was (OLUC) mixed with solvents, as ethanol, 2- propanol and 1-butanol inside a cylindrical containers in the ratio 1: 3, respectively. Approximately 20.0 L of pool of lubricating oils contaminated coming from medium and small vehicles were collected in dealership representative of the northern region of the Holy Spirit. The best optimized conditions of operate were: 30 °C temperature; 20 minutes and 37 kHz of US frequenc. The incorporation of OLUC solvents was carried out at 60 °C for 5 XVIII min magnetic stirring at 250 rpm. After the extraction and flocculation operations, the recovered oil was subjected to the determination of their physicochemical properties as ANP Ordinance 130/1999. The analysis identified that the oil recovered by the use of US and 1-butanol has the best overall performance (≈ 80.0% w/w) and properties with fewer acidity (0.0141 mg KOH/g), lower viscosity index (97), lower water content (0.07% w/w) and lower ferromagnetic severity index (1.44). By comparing the developed method, other methods extraction by mechanical or magnetic stirring, it was observed that the application of ultrasound increases the process yield of at least 25% (w/w) and reduces total process time of at least 16 hours. The extraction and flocculation promoted by ultrasonic waves and solvents reduces the energy and the time required. In order to reduce environmental impacts and overall process efficiency, the method developed in this study is very promising.
Um estudo sobre a viabilidade técnico-financeira de instalação de um parque eólico offshore na região norte do Espírito Santo
(Universidade Federal do Espírito Santo, 2015-08-26) Santos, Karla Rossini Gomes; Chaves, Gisele de Lorena Diniz; Celeste, Wanderley Cardoso; Rocha, Helder Roberto de Oliveira
The generation of electrical energy by using wind power has improved over the last decade, what explains wide enterprising, especially in Brazil, however it is not noticed a substantial investment in the state of Espírito Santo (ES). The main detail of this kind of renewal energy is the fact that the winds, along the terrestrial surface, do not have a constant speed. Consequently, the wind turbine works with unstable speed. It requires the generator among the wind turbine being able to generate electrical energy with stable frequency in a certain level of speed variation, making visible the need of studies to define the analyze and the viability of this enterprising, what motivated the present research, which the goal is to show a technical and simple study around the area of Urussuquara and a simple financial analyze about a local demanding for energy in order to start a discussion about the viability to install an offshore wind farm in the state of Espírito Santo. Besides the technical and financial viability, it is also necessary to consider the contribution of a wind park in the Espírito Santo by increasing and diversifying the energy of the state, decreasing by this way the dependence of thermoelectric plant and other states that generate electrical energy. The study was performed for Urussuquara Island – ES, seeking to supply the demand of energy performed by the city of São Mateus during 2014 which was 170.590MWh. The outcoming result showed that would be necessary seven windmills of 6MW of power to supply such need. A simplified financial analyze based in payback showed that such investment would be recovered within 6 years and 3 months, what compares to a part of lifetime of a wind farm, therefore it is possible to conclude such enterprising would be, indeed, affordable through the technical and financial view as well.

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