Estudo de reatores eletroquímicos para remoção de Cu2+ , Zn2+, Fenol e BTEX em água produzida

The production of water has become one of the most important wastes in the petroleum industry, specifically in the up stream segment. The treatment of this kind of effluents is complex and normally requires high costs. In this context, the electrochemical treatment emerges as an alternative methodology for treating the wastewaters. It employs electrochemical reactions to increase the capability and efficiency of the traditional chemical treatments for associated produced water. The use of electrochemical reactors can be effective with small changes in traditional treatments, generally not representing a significant additional surface area for new equipments (due to the high cost of square meter on offshore platforms) and also it can use almost the same equipments, in continuous or batch flow, without others high costs investments. Electrochemical treatment causes low environmental impact, because the process uses electrons as reagent and generates small amount of wastes. In this work, it was studied two types of electrochemical reactors: eletroflocculation and eletroflotation, with the aim of removing of Cu2+, Zn2+, phenol and BTEX mixture of produced water. In eletroflocculation, an electrical potential was applied to an aqueous solution containing NaCl. For this, it was used iron electrodes, which promote the dissolution of metal ions, generating Fe2+ and gases which, in appropriate pH, promote also clotting-flocculation reactions, removing Cu2+ and Zn2+. In eletroflotation, a carbon steel cathode and a DSA type anode (Ti/TiO2-RuO2-SnO2) were used in a NaCl solution. It was applied an electrical current, producing strong oxidant agents as Cl2 and HOCl, increasing the degradation rate of BTEX and phenol. Under different flow rates, the Zn2+ was removed by electrodeposition or by ZnOH formation, due the increasing of pH during the reaction. To better understand the electrochemical process, a statistical protocol factor (22) with central point was conducted to analyze the sensitivity of operating parameters on removing Zn2+ by eletroflotation, confirming that the current density affected the process negatively and the flow rate positively. For economical viability of these two electrochemical treatments, the energy consumption was calculated, taking in account the kWh given by ANEEL. The treatment cost obtained were quite attractive in comparison with the current treatments used in Rio Grande do Norte state. In addition, it could still be reduced for the case of using other alternative energy source such as solar, wind or gas generated directly from the Petrochemical Plant or offshore platforms

Digestibility and performance of pacu (Piaractus mesopotamicus) juveniles - fed diets containing different protein, lipid and carbohydrate levels

Due to lack of information on the use of non-protein energy sources in diets for pacu (Piaractus mesopotamicus), a 2 x 2 x 3 factorial experiment was conducted to evaluate the performance and digestibility of 12 diets containing approximately two crude protein (CP; 220 and 250 g kg(-1)), two lipid (40 and 80 g kg(-1)) and three carbohydrate levels (410, 460 and 500 g kg(-1)). The pacu juveniles-fed diets containing 220 g kg(-1) CP did not respond (P > 0.05) to increased dietary lipid and carbohydrate levels, but the fish-fed diets containing 250 g kg(-1) CP showed a better feed conversion ratio. There were interactions in weight gain (WG), specific growth rate (SGR), crude protein intake (CPI) and feed conversion rate (FCR) dependent on dietary carbohydrate and lipid levels, showing positive effects of increasing carbohydrate levels only for fish-fed diets containing 80 g kg(-1) lipid level. However, when the diets contained 40 g kg(-1) lipid, the best energy productive value (EPV) results were obtained at 460 g kg(-1) carbohydrate. A higher usage of lipids (80 g kg(-1)) reduced CPI and was detrimental to protein [apparent digestibility coefficient (ADC)(CP)] and energy (ADC(GE)), but did not affect growth. The ADC(GE) improved proportionally as dietary carbohydrate levels increased (P < 0.05), increasing the concentration of digestible energy. In addition, the WG, CPI, ADC(GE) results showed best use of the energy from carbohydrates when dietary protein level was 250 g kg(-1) CP. The utilization of 250 g kg(-1) CP in feeds for juvenile pacu for optimal growth is suggested. Therefore, the optimum dietary lipid and carbohydrate levels depend on their combinations. It can be stated that pacu uses carbohydrates as effectively as lipids in the maximization of protein usage, as long as it is not lower than 250 g kg(-1) CP or approximately 230 g kg(-1) digestible protein.

Desenvolvimento, pobreza e meio ambiente no seridó potiguar: um estudo centrado nas micro-regiões do seridó oriental e ocidental

This research work intends to carry out a study focused on the dynamic between development, poverty reduction and conservation of natural resources. To consider this relationship to the region chosen was the micro-region of Eastern and Western Seridó in the state of Rio Grande do Norte. In recent years, several studies (Araújo, 2011; BASTOS, 2009) have pointed out that after a period of economic crisis in its tripodproductive, formed by the activities of farming, cotton farming, mining and faced in the eighties, this region of the State of Rio Grande do Norte, has not only shown signs of economic recovery but also improve their social indicators. On the other hand, studies of desertification as the view of the state of RN (produced in cooperation between the Government of RN and research institutions) and the Sustainable Development Plan of Seridó (ADES, 2000), indicate that there is an ongoing French process of degradation of natural resources that is capable of compromising the ability of sustaining such a system. To verify this reality and likely finding this relationship, this work is adopted for this study, the analysis of evolution of secondary data from official bodies such as the IBGE on HDI, per capita income and other social indicators between 2000 and 2009. Here is another time of the survey analysis of qualitative data collected from interviews with institutions of academic intervention in nature, researchers at the Federal University of Rio Grande do Norte (UFRN) State agencies that address the issue of the Middle Environment in Seridó: Institute for Sustainable Development of the NB (IDEMA) and the Brazilian Institute of Environment and the Amazon (IBAMA) and institutions of direct intervention in the region, as the Agency's Sustainable Development Seridó (adhesive) and the Joint Semi-Arid (ASA). After crossing data from quantitative and qualitative, it was found that the dynamics of the region's economic Seridó Potiguar partially answers the improvement of social indicators of poverty. Contribution by the State in this shared stock transfer income. Regarding the influence of productive restructuring in the region on issues of environment, it is noted that the ceramic tile industry, responsible for the absorption percentage of the population with limited ingress into the urban economy, given the low education, accounts for the increase of susceptibility to the ongoing process of desertification in North Seridó Rio Grande. We conclude finally that the guarantee of increased income, freedom and conservation of natural resources ensures primarily by changing the beliefs and values, especially on the part of the business sector, which use natural resources so predatory, aimed at maintaining their rates of return on investment. And concomitantly, the synchronization between technological change, through the use of new energy sources, and institutional change.

O sistema de certificação do etanol brasileiro sob a ótica do princípio constitucional do desenvolvimento sustentável

The gradual inclusion of biofuels is a necessary change that countries must include in their energy mixes. Energy sources still widely used in the world, such as oil and coal, are endowed with a high pollution load to the environment, bringing damages to the water, to the air and to humans as well. In addition, although there are conflicting studies, they are also identified as major causes of the greenhouse effect and the global warming phenomenon. They are, moreover, finite sources of energy, given that its reserves will surely run out. However, even if the introduction of biofuels, such as ethanol, in the energy mix is crucial for the survival of the present and future populations, this insertion cannot settle so disorderly and, thus, one must ensure the quality of these resources and promote transparency in international trade. In this manner, a certification process for ethanol is essential to attest that this biofuel meets the sustainable requirements defined for its production. Hence, this study sought to address the importance of the adoption of certification in the ethanol industry, according to the principle of sustainable development, by analyzing the evolution of its concept, its combination with the fundamental objectives sculptured in the Constitution of 1988, its regulation under Brazilian laws and the need for a balance between economic activities and the mentioned principle. The work also encompassed the criteria used to establish certification standards and their participating actors, combined with a study of ongoing initiatives. Finally, the consequences of the adoption of a certification process for ethanol in Brazil were presented, both in terms of sustainable development and in international trade

Fator de decisão na adoção de um sistema de micro-cogeração de energia a gás natural :um estudo em Hotéis três estrelas

The natural gas perform a essential paper, not only in primary sectors of energy, but also in others sectors of economy. The use natural gas will have expansion in Brazil, motivated by governmental decision to increase the participation of this fuel in the Brazilian energy matrix from 4% to 12% up until 2010. in order to reach the objective related to increase the consumption of natural gas in the energy matrix and to propose solutions to attend the electric requirements of heart and refrigeration, using natural gas as primary power plant. This thesis has a main objective to analysis the perception of businessmen of hotel sector about the feasability of investment with micro-cogeneration system by natural gas in their hotel in turistic sector, in Natal/RN. It s show a case for the hotels selected analyzing the actual knowledge of businessmen about alternative of new technology in generation of owner energy. There was make a interview using a standard form researching information about this topic. In this interview has shown 4 (four) canaries for businessmen with different configurations of investment in micro-cogeneration. Two of this canaries uses the project finance like option to make fasible this projects. The resulteis showed who businessmen has insecurity to make decision to put in office alone, or with a local company, and perhaps with a national company to perform for a alternative energy system, justifying, the alone feasability and without information by local businessmen. Apart from that, they are receptive for a option to put in office in micro-cogeneration configured in the settings using project finance

Desempenho, parâmetros plasmáticos e características de carcaça de novilhos alimentados com farelo de girassol e diferentes fontes energéticas, em confinamento

Avaliaram-se consumo, desempenho, parâmetros plasmáticos e características de carcaça de 24 novilhos, 3/4 Simental 1/4 Nelore, com peso médio inicial de 370 kg. As dietas foram compostas por 55% de silagem de milho e diferentes fontes energéticas: milho (MI) e substituição parcial do milho pela casca de soja (CS) ou pelo farelo de gérmen de milho (FGM), tendo como fonte de proteína o farelo de girassol. O período de avaliação de consumo e ganho de peso foi de 49 dias. Foram realizadas amostragens de sangue para mensuração dos parâmetros plasmáticos: glicose, uréia, proteína total e albumina. As meia-carcaças direitas resfriadas foram utilizadas para medir a área de olho de lombo (AOL), a espessura de gordura (EG) e o comprimento de carcaça. As dietas não influenciaram os parâmetros plasmáticos. A média obtida para uréia plasmática foi elevada (26,1 mg/dL). As diferentes fontes energéticas não afetaram o ganho de peso e a conversão alimentar, com médias de 1,15 kg/dia e 9,17 kg de MS ingerida/kg de ganho. Não houve efeito sobre o rendimento de carcaça (52,8% peso final e 63,11% PCV), AOL (63,6 cm²) e EG (4,7 mm). O grão de milho pode ser substituído parcialmente pela casca de soja e pelo farelo de gérmen de milho, em dietas para novilhos em confinamento, sem afetar o desempenho e as características de carcaça, permitindo que a escolha entre esses ingredientes seja realizada pela análise econômica.

Avaliação da silagem de grãos de milho úmido com diferentes volumosos para tourinhos em terminação: desempenho e características de carcaça

O experimento foi realizado com o objetivo de comparar os efeitos do fornecimento de silagem de grãos de milho úmido com o milho em grão seco, associados à silagem de milho ou ao bagaço in natura de cana-de-açúcar, sobre o desempenho e as características da carcaça de bovinos em terminação. em blocos ao acaso e esquema fatorial 2 × 2, 28 tourinhos Santa Gertrudes (dez meses de idade e peso corporal inicial de 245 kg) foram mantidos em confinamento durante 142 dias. Os animais foram mantidos em baias individuais e receberam dietas com 12 e 20% da MS em forma de bagaço ou silagem, respectivamente. O milho úmido foi moído e ensilado quando se encontrava com 30% de umidade. Não houve interação significativa tipo de volumoso x tipo de processamento do milho sobre as variáveis estudadas. O bagaço mostrou-se viável como fonte exclusiva de fibra, apesar de os resultados de ganho de peso, eficiência alimentar, peso e rendimento de carcaça e espessura de gordura subcutânea terem sido inferiores aos obtidos com a silagem de milho. O ganho diário de peso nos animais alimentados com o bagaço foi em torno de 1,3 kg, enquanto, com a silagem, foi de 1,5 kg. O consumo de MS não foi influenciado pelo tipo de volumoso ou pelo processamento do milho. O uso da silagem de grãos de milho úmido melhorou a eficiência alimentar em 9,7% e reduziu o peso do fígado quando comparado ao milho seco, mas não alterou as demais características avaliadas.

Análise Energética da cultura do crambe (Crambe abyssinica hochst) produzida em plantio direto

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Controlador adaptativo por posicionamento de pólos e estrutura variável aplicado ao controle de geradores eólicos baseados em máquina de indução duplamente alimentada

In the last decade, the renewable energy sources have present a major propulsion in the world due to several factors: political, environmental, financial and others. Within this context, we have in particular the energy obtained through wind, wind energy - that has highlighted with rapid growth in recent years, including in Brazil, mostly in the Northeast, due to it s benefit-cost between the clean energies. In this context, we propose to compare the variable structure adaptive pole placement control (VS-APPC) with a traditional control technique proportional integral controller (PI), applied to set the control of machine side in a conversion system using a wind generator based on Double-Fed Induction Generator (DFIG). Robustness and performance tests were carried out to the uncertainties of the internal parameters of the machine and variations of speed reference.

Análise de desempenho de um fogão solar construído a partir de sucatas de antena de tv

Given the growing environmental crisis caused by degradation, mainly due to the use of polluting energy sources, increasing the growing use of renewable energies worldwide, with emphasis on solar energy, an abundant supply and available to everyone, which can be harnessed in several ways: electricity generation; dehydration of food; heating, disinfection and distillation and cooking. The latter has as its primary feature the viability of clean, renewable energy for society, combating ecological damage caused by large-scale use of firewood for cooking foods, use in tropical countries with high solar radiation, and has funding NGOs throughout the world with the goal of achieving low-income population. The proposed project consists of a solar cooker for concentration, working from the reflection of sunlight by a hub that they converge to a focal point at the bottom of the pot, getting lots of heat. The solar cooker under study consists of two elliptical reflecting parabolas made from the recycling of scrap TV antenna, having 0.29 m² of surface area for each antenna, which were covered by multiple mirrors of 2 mm thick and mounted on a metal structure, with correction for the mobility of the apparent movement of the sun. This structure was built with the recycling of scrap metal, possessing a relatively low cost compared with other solar cookers, around US$ 50.00. This cost becomes negligible, since that will involve a great benefit to not have fuel costs for each meal, unlike the use of gas or firewood for cooking food. The tests show that the cooker has reached the maximum temperature of 740 ° C, for boiling water in an average time of 28 minutes, cooking various types of foods such as potatoes, rice and pasta in an average time of 45 minutes and still going as a solar oven, making pizza baking and meat. These cooking times do not differ much from the cooking times on a gas stove, it becomes the solar cooker as a good consumer acceptance, and furthermore not to deliver the same gases that can poison the food as with the wood stove. Proves the viability of using the stove to cook or bake in two daily meals for a family, still presenting a position to improve his performance with the addition of new materials, equipment and techniques

Sistema de destilação solar com pré-aquecimento em concentrador cilindro parabólico

Due to the increasing need to promote the use of resources that support the environment and the clean industry, the science has developed in the area of natural resource use as well as enhanced use of the renewable energy sources. Considering also the great need for clean water and wide availability of salt or brackish water, added to the great solar energy potential in northeastern of the Brazil, it was developed a solar distiller whose main difference is its system of pre-solar heating also. From experimental adjustments, the system was developed by the use of a cylindrical solar concentrator coupled to a conventional distiller. The system is designed such that attempt to facilitate the process termination trap to ensure constant movement of the fluid mass and thus enable higher temperatures to the system and thus fetch a higher amount of distillate collected. In a stage of the experiment were used a forced circulation to try to further increase the amount of energy exchange system. To develop the study were set up four settings for comparison in which one was only distiller simple as basic parameter, the second proposed configuration were with the coupling of the concentration triggered manually every 30 minutes to monitor the sun, the third configuration occurred with automatic triggering of a timer, and the fourth configuration was also used a pumping system that tried to improve the circulation of the fluid. With the comparative analysis of the results showed a gain in the amount of distillate system, especially in the forced model

Pyrolysis and combustion of pulp mill lime sludge

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Condições de energia de hawking e ellis e a equação de raychaudhuri

In the Einstein s theory of General Relativity the field equations relate the geometry of space-time with the content of matter and energy, sources of the gravitational field. This content is described by a second order tensor, known as energy-momentum tensor. On the other hand, the energy-momentum tensors that have physical meaning are not specified by this theory. In the 700s, Hawking and Ellis set a couple of conditions, considered feasible from a physical point of view, in order to limit the arbitrariness of these tensors. These conditions, which became known as Hawking-Ellis energy conditions, play important roles in the gravitation scenario. They are widely used as powerful tools for analysis; from the demonstration of important theorems concerning to the behavior of gravitational fields and geometries associated, the gravity quantum behavior, to the analysis of cosmological models. In this dissertation we present a rigorous deduction of the several energy conditions currently in vogue in the scientific literature, such as: the Null Energy Condition (NEC), Weak Energy Condition (WEC), the Strong Energy Condition (SEC), the Dominant Energy Condition (DEC) and Null Dominant Energy Condition (NDEC). Bearing in mind the most trivial applications in Cosmology and Gravitation, the deductions were initially made for an energy-momentum tensor of a generalized perfect fluid and then extended to scalar fields with minimal and non-minimal coupling to the gravitational field. We also present a study about the possible violations of some of these energy conditions. Aiming the study of the single nature of some exact solutions of Einstein s General Relativity, in 1955 the Indian physicist Raychaudhuri derived an equation that is today considered fundamental to the study of the gravitational attraction of matter, which became known as the Raychaudhuri equation. This famous equation is fundamental for to understanding of gravitational attraction in Astrophysics and Cosmology and for the comprehension of the singularity theorems, such as, the Hawking and Penrose theorem about the singularity of the gravitational collapse. In this dissertation we derive the Raychaudhuri equation, the Frobenius theorem and the Focusing theorem for congruences time-like and null congruences of a pseudo-riemannian manifold. We discuss the geometric and physical meaning of this equation, its connections with the energy conditions, and some of its several aplications.

Refrigerator COP with thermal storage

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Optimisation of environmental gas cleaning routes for solid wastes cogeneration systems - Part I - Analysis of waste incineration steam cycle

Research of advanced technologies for energy generation contemplates a series of alternatives that are introduced both in the investigation of new energy sources and in the improvement and/or development of new components and systems. Even though significant reductions are observed in the amount of emissions, the proposed alternatives require the use of exhaust gases cleaning systems. The results of environmental analyses based on two configurations proposed for urban waste incineration are presented in this paper; the annexation of integer (Boolean) variables to the environomic model makes it possible to define the best gas cleaning routes based on exergetic cost minimisation criteria. In this first part, the results for steam cogeneration system analysis associated with the incineration of municipal solid wastes (MSW) is presented. (c) 2007 Elsevier Ltd. All rights reserved.