Estudo das propriedades físico-químicas do biodiesel e suas influências na deterioração dos elastômeros aplicados no sistema de injeção dos motores diesel

The biodiesel use has become important due to its renewable character and to reduce environmental impacts during the fuel burning. Theses benefit will be valid if the fuel shows good performance, chemistry stability and compatibility with engines. Biodiesel is a good fuel to diesel engines due to its lubricity. Then, the aimed of this study was to verify the physicalchemistry properties of biodiesel and their correlations with possible elastomers damage after biodiesel be used as fuel in an injection system. The methodology was divided in three steps: biodiesels synthesis by transesterification of three vegetable oil (soybean, palm and sunflower) and their physical-chemistry characterization (viscosity, oxidative stability, flash point, acidity, humidity and density); pressurized test of compatibility between elastomers (NBR and VITON) and biodiesel, and the last one, analyze of biodiesels lubricity by tribological test ball-plan( HFRR). Also, the effect of mixture of biodiesel and diesel in different concentrations was evaluated. The results showed that VITON showed better compatibility with all biodiesel blends in relation to NBR, however when VITON had contact with sunflower biodiesel and its blends the swelling degree suffer higher influences due to biodiesel humidity. For others biodiesels and theirs blends, this elastomer kept its mechanical properties constant. The better tribological performance was observed for blends with high biodiesel concentration, lower friction coefficient was obtained when palm biodiesel was used. The main mechanisms observed during the HFRR tests were abrasive and oxidative wear

Dinâmica de transposição de herbicida através de palha de aveia-preta utilizando diferentes pontas de pulverização

A transposição da palha por herbicidas aplicados em pré ou pós-emergência durante a aplicação é determinante na sua eficiência, dinâmica e impacto ambiental. O experimento foi conduzido no Núcleo de Pesquisas Avançadas em Matologia - FCA/UNESP, campus de Botucatu-SP, tendo como objetivo avaliar o desempenho de diferentes modelos de pontas de pulverização na transposição em quantidades crescentes de palha de aveia-preta (Avena strigosa). Os tratamentos foram constituídos pelo monitoramento do traçador corante Azul Brilhante (FDC-1) a 3.000 ppm, pulverizado com as pontas de pulverização XR11002-VS, TJ60-11002VS, FL-5VS, DG11002-VS, TXVK-8, TT11002-VP e AI11002-VS, utilizando, respectivamente, as pressões de trabalho de 1,4; 2,0; 1,5; 2,0; 4,9; 3,0 e 3,0 kgf cm² e volume de calda de 200, 200, 428, 200, 213 e 270 L ha-1 sobre quantidades de 0, 1, 2, 4, 6, 8, 10 e 12 t ha-1 de palha de aveia-preta. O delineamento utilizado foi o inteiramente casualizado, com sete tratamentos e cinco repetições, as quais foram constituídas de caixas plásticas com palha acondicionada sobre um fundo falso de área conhecida, sendo este lavado após as aplicações, para posterior quantificação do traçador em espectrofotometria. O modelo de Mitscherlich simplificado (Y = 10 ^ (2 - (C*X))) mostrou ajuste satisfatório para os dados originais de traçador que transpôs a palha, apresentando coeficientes de determinação (R²) elevados, oscilando entre 0,9782 e 0,9971. Todos os modelos de pontas de pulverização mostraram-se similares na transposição da palha pelo traçador. As porcentagens médias de transposição foram de 43,00; 18,77; 3,73; 0,78; 0,17; 0,04 e 0,01% para as quantidades de 1, 2, 4, 6, 8, 10 e 12 t ha-1 de palha, respectivamente.

Remoção de óleo da água de produção por flotação em coluna utilizando tensoativos de origem vegetal

In the petroleum industry, water is always present in the reservoir formation together with petroleum and natural gas and this fact provokes the production of water with petroleum, resulting in a great environmental impact. Several methods can be applied for treatment of oily waters, such as: gravitational vases, granulated media filtration systems, flotation process, centrifugation process and the use of hydrocyclones, which can also be used in a combined way. However, the flotation process has showed a great efficiency as compared with other methods, because these methods do not remove great part of the emulsified oil. In this work was investigated the use of surfactants derived from vegetable oils, OSS and OGS, as collectors, using the flotation process in a glass column with a porous plate filter in its base for the input of the gaseous steam. For this purpose, oil/water emulsions were prepared using mechanical stirring, with concentrations around 300 ppm. The air flow rate was set at 700 cm3/min and the porous plate filter used for the generation of the air bubbles has pore size varying from 16 to 40 Pm. The column operated at constant volume (1500mL). A new methodology has been developed to collect the samples, where, instead of collecting the water phase, it was collected the oil phase removed by the process in the top of the flotation column. It has been observed that it is necessary to find an optimum surfactant concentration to achieve enhanced removal efficiency. Being for OSS 1.275 mmol/L and for OGS 0.840 mmol/L, with removal efficiencies of 93% and 99%, respectively, using synthetic solutions. For the produced water, the removal in these concentrations was 75% for OSS and 65% for OGS. It is possible to remove oil from water in a flotation process using surfactants of high HLB, fact that is against the own definition of HLB (Hydrophile-Lipophile Balance). The interfacial tension is an important factor in the oil removal process using a flotation process, because it has direct interference in the coalescence of the oil drops. The spreading of the oil of the air bubble should be considered in the process, and for the optimum surfactant concentrations it reached a maximum value. The removal kinetics for the flotation process using surfactants in the optimum concentration has been adjusted according to a first order model, for synthetic water as for the produced water.

Teores de metais na biomassa de Egeria densa, Egeria najas e Ceratophyllum demersum

Este estudo foi realizado com o objetivo de se estimar o conteúdo de elementos metálicos presentes em três macrófitas aquáticas submersas, procurando avaliar a participação destas plantas na remoção destes elementos na água e criar base de dados que permita prever o impacto ambiental do descarte delas em solo ou na própria água. As amostras foram desidratadas, moídas e encaminhadas aos laboratórios para análise e quantificação dos elementos. Para as três espécies, a maior concentração de elementos foi observada durante o verão, ocorrendo declínio nas concentrações durante o inverno, principalmente para os elementos vanádio e chumbo. Não foi detectada presença do elemento mercúrio em nenhuma das amostras.

Constribuição técnica de um sistema de emulsão inversa a base de óleos vegetais para fluidos de perfuração

The developments in formulating drilling fluids to apply in petroleum fields are based on new technologies and environmental challenges, where the technical performance of a developed drilling fluid is used to produce a minimum environmental impact, showing great economy in costs. It is well known that the potential use of oil-based drilling fluids is limited because these fluids when discharged in the sea do not disperse as much as water-based ones and may form waterproof films in the seabed, having a profound effect on plants and animals living in this environment. The current works have been made in investigating fluids called pseudofluids, which are synthetic ester-based, n-paraffin-based and other fluids formed from inverse emulsion. In this research the principal parameters involved in inverse emulsion process were studied, in laboratory scale, using esters as main component. Others commercial drilling fluids were used as comparative samples, as well as samples from laboratory and field where these drilling fluids are being applied. Concentrations of emulsifier and organophilic clay, which are viscosity donor, were varied to verify the influence of these parameters, in different oil/water ratios (55/45, 60/40, 65/35, 70/30, and 75/25). The salt concentration (NaCl) is an indicative parameter of stability and activity of an esterbased fluid. In this research the salt concentration was varied in 10,000, 20,000, and 50,000 ppm of NaCl. Some rheological properties of the produced fluids were studied, such as: initial gel, plastic viscosity, yield point, and apparent viscosity. Through the obtained rheological measures, the existence of two systems could be verified: fluid and flocculated. It could be noticed that the systems were influenced, directly, by the oil/water ratio and emulsifier, organophilic clay and NaCl concentrations. This study showed the viability to use an ester obtained from a regional vegetable product babaçu coconut oil to obtain an efficient and environmental safe drilling fluid

Estudo das características físico-químicas e funcionalidade de bagaços de frutas tropicais desidratados em leito de jorro

Fruits are rich sources of bioactive compounds, including phenolic compounds. Tropical fruit cultivation is an important productive segment in Brazilian Northeast. Its industrialization generates solid wastes as co-products, with potential environmental impact. Considering the recognized bioactive content of fruit and its derivatives, this research has the objective of investigating acerola (Malpighia glabra L.), cajá-umbu (Spondia ssp), jambolan (Syzygium cumini) and pitanga (Eugenia uniflora) dried wastes obtained by spouted bed drier. It was analyzed the physical-chemical composition, solubility and microphotographic aspect of these dried wastes. Besides this, it was also evaluated the bioactive content, antioxidant activity and inhibitory activity against aamylase and a-glycosidase enzymes of water and ethanol (70%, 80% e 100% v/v) extracts prepared from fruit dried wastes, as well as their possible correlations. The dried fruit wastes showed high phenolic (606.04 to 3074.6 mg GAE eq/100 g sample), anthocyanin (478.7 mg/100 g for jambolan) and ascorbic acid (2748.03 mg/100 g for acerola) contents, as well as high antioxidant DPPH activity (14.27 a 36.30 mg Trolox eq/g sample). The extracts exhibited moderate to high a-amylase inhibition (23.97% a 76.58%) and high α-glycosidase inhibition, which 99.32% peak was reached for ethanol 70% pitanga extracts. It was also observed great positive correlation between phenolic content and DPPH activity (0.97 for acerola), anthocyanin (0.95 for jambolan) and α- glycosidase inhibition (0.98 for acerola). The α-glycosidase inhibition also correlated well with the antioxidant activity for all fruit extracts. The results show that these dried fruit wastes are valuable material for further applications as functional ingredients

Tratamento de água de produção de petróleo visando o aproveitamento na obtenção de barrilha

The petroleum production is associated to the produced water, which has dispersed and dissolved materials that damage not only the environment, but also the petroleum processing units. This study aims at the treatment of produced water focusing mainly on the removal of metals and oil and using this treated water as raw material for the production of sodium carbonate. Initially, it was addressed the removal of the following divalent metals: calcium, magnesium, barium, zinc, copper, iron, and cadmium. For this purpose, surfactants derived from vegetable oils, such as coconut oil, soybean oil, and sunflower oil, were used. The investigation showed that there is a stoichiometric relationship between the metals removed from the produced water and the surfactants used in the process of metals removal. It was also developed a model that correlates the hydrolysis constant of saponified coconut oil with the metal distribution between the resulting stages of the proposed process, flocs and aqueous phases, and relating the results with the pH of the medium. The correlation coefficient obtained was 0.963. Next, the process of producing washing soda (prefiro soda ahs ou sodium carbonate) started. The resulting water from the various treatment approaches from petroleum production water was used. During this stage of the research, it was observed that the surfactant assisted in the produced water treatment, by removing some metals and the dispersed oil entirety. The yield of sodium carbonate production was approximately 80%, and its purity was around 95%. It was also assessed, in the production of sodium carbonate, the influence of the type of reactor, using a continuous reactor and a batch reactor. These tests showed that the process with continuous reactor was not as efficient as the batch process. In general, it can be concluded that the production of sodium carbonate from water of oil production is a feasible process, rendering an effluent that causes a great environmental impact a raw material with large scale industrial use

Cerâmicas avançadas no processo de retificação cilíndrica externa de mergulho utilizando a técnica da mínima quantidade de lubrificação (MQL) com rebolos diamantados

Nas últimas duas décadas, as cerâmicas avançadas têm sido exaustivamente utilizadas em aplicações na indústria devido às suas propriedades de elevada resistência ao desgaste e dureza. Entretanto, ainda se tem um alto custo agregado ao acabamento da peça. Esse acabamento geralmente é feito pelo processo de retificação, único processo economicamente viável que produz superfícies de elevada qualidade e precisão geométrica. Nesse contexto, as empresas vêm buscando a otimização no processo de retificação como, por exemplo, a redução do fluxo de fluido de corte utilizado, o que também visa atender exigências mundiais de preservação ambiental. Desta forma, este projeto pretendeu explorar a técnica da Mínima Quantidade de Lubrificação (MQL) na retificação cilíndrica externa de mergulho em cerâmicas com rebolos diamantados. Foram utilizados dois métodos de refrigeração: o convencional e o MQL, com três avanços de corte para cada caso. Foram usados um bocal convencional e um bocal para o MQL, tendo este um uniformizador de saída do jato. Foram analisadas como variáveis de saída: a emissão acústica, relação G, aspecto da superfície via microscopia eletrônica de varredura (MEV), rugosidade e circularidade. Assim, embora a refrigeração convencional ainda apresente os melhores resultados em comparação com a refrigeração com MQL, esta última pode atender os requisitos necessários para diversas aplicações, em especial quando utilizadas baixas espessuras equivalentes de corte (h eq). Além disso, a técnica de MQL possui a vantagem de gerar um menor impacto ambiental em comparação com a lubrificação convencional, devido ao uso mínimo de fluido de corte cujo descarte é cada vez mais regulamentado e custoso.

Determinação de Ba, Cd, Cr, Cu, Ni, Pb, Sn e Zn em Tainha (Mugil brasiliensis) nos estuários potiguares

Heavy metals can cause problems of human poisoning by ingestion of contaminated food, and the environment, a negative impact on the aquatic fauna and flora. And for the presence of these metals have been used for aquatic animals biomonitoramento environment. This research was done in order to assess the environmental impact of industrial and domestic sewage dumped in estuaries potiguares, from measures of heavy metals in mullet. The methods used for these determinations are those in the literature for analysis of food and water. Collections were 20 samples of mullet in several municipality of the state of Rio Grande do Norte, from the estuaries potiguares. Were analyzed the content of humidity, ash and heavy metals. The data were subjected to two methods of exploratory analysis: analysis of the main components (PCA), which provided a multivariate interpretation, showing that the samples are grouped according to similarities in the levels of metals and analysis of hierarchical groupings (HCA), producing similar results. These tests have proved useful for the treatment of the data producing information that would hardly viewed directly in the matrix of data. The analysis of the results shows the high levels of metallic species in samples Mugil brasiliensis collected in Estuaries /Potengi, Piranhas/Açu, Guaraíra / Papeba / Arês and Curimataú

Degradação eletroquímica de benzeno, tolueno e xileno via oxidação eletroquímica utilizando eletrodo Ti/Pt

This work is directed to the treatment of organic compounds present in produced water from oil using electrochemical technology. The water produced is a residue of the petroleum industry are difficult to treat , since this corresponds to 98 % effluent from the effluent generated in the exploration of oil and contains various compounds such as volatile hydrocarbons (benzene, toluene, ethylbenzene and xylene), polycyclic aromatic hydrocarbons (PAHs), phenols, carboxylic acids and inorganic compounds. There are several types of treatment methodologies that residue being studied, among which are the biological processes, advanced oxidation processes (AOPs), such as electrochemical treatments electrooxidation, electrocoagulation, electrocoagulation and eletroredution. The electrochemical method is a method of little environmental impact because instead of chemical reagents uses electron through reactions of oxide-reducing transforms toxic substances into substances with less environmental impact. Thus, this paper aims to study the electrochemical behavior and elimination of the BTX (benzene, toluene and xylene) using electrode of Ti/Pt. For the experiment an electrochemical batch system consists of a continuous source, anode Ti/Pt was used, applying three densities of current (1 mA/cm2, 2,5 mA/cm2 and 5 mA/cm2). The synthetic wastewater was prepared by a solution of benzene, toluene and xylene with a concentration of 5 ppm, to evaluate the electrochemical behavior by cyclic voltammetry and polarization curves, even before assessing the removal of these compounds in solution by electrochemical oxidation. The behavior of each of the compounds was evaluated by the use of electrochemical techniques indicate that each of the compounds when evaluated by cyclic voltammetry showed partial oxidation behavior via adsorption to the surface of the Ti/Pt electrode. The adsorption of each of the present compounds depends on the solution concentration but there is the strong adsorption of xylene. However, the removal was confirmed by UV-Vis, and analysis of total organic carbon (TOC), which showed a percentage of partial oxidation (19,8 % - 99,1 % TOC removed), confirming the electrochemical behavior already observed in voltammetry and cyclic polarization curves

Custo para implantação de Astronium fraxinifolium schott em área degradada utilizando-se adubos verdes e lodo de esgoto

A utilização de recursos naturais e a necessidade de recuperação de áreas degradadas têm assumido importância global, sendo que a estimativa de custos garante a viabilidade econômica, para implantação de projetos de conservação ou recuperação. Foram estimados os custos para implantação de um hectare da espécie arbórea Gonçalo-Alves (Astonium fraxinifolium Schott), com adubação verde, em Latossolo Vermelho degradado, como se segue: Gonçalo-Alves + Feijão-de-porco; Gonçalo-Alves + crotalária; Gonçalo-Alves + fórmula NPK (04-14-08); e Gonçalo-Alves + braquiária + lodo. A estimativa do custo de implantação de Gonçalo-Alves, para a região leste do Estado do Mato Grosso do Sul, variou entre R$ 2.829,13 e R$ 3.872,21. O tratamento com braquiária + lodo de esgoto foi o mais econômico, considerando-se um período de cinco anos, além dos benefícios ambientais relacionados ao descarte viável deste resíduo, por estações de tratamento de esgoto.

Eficiência de extração de cobre e níquel utilizando sistemas microemulsionados bifásicos e trifásicos

The environmental impact due to the improper disposal of metal-bearing industrial effluents imposes the need of wastewater treatment, since heavy metals are nonbiodegradable and hazardous substances that may cause undesirable effects to humans and the environment. The use of microemulsion systems for the extraction of metal ions from wastewaters is effective when it occurs in a Winsor II (WII) domain, where a microemulsion phase is in equilibrium with an aqueous phase in excess. However, the microemulsion phase formed in this system has a higher amount of active matter when compared to a WIII system (microemulsion in equilibrium with aqueous and oil phases both in excess). This was the reason to develop a comparative study to evaluate the efficiency of two-phases and three-phases microemulsion systems (WII and WIII) in the extraction of Cu+2 and Ni+2 from aqueous solutions. The systems were composed by: saponified coconut oil (SCO) as surfactant, n-Butanol as cosurfactant, kerosene as oil phase, and synthetic solutions of CuSO4.5H2O and NiSO4.6H2O, with 2 wt.% NaCl, as aqueous phase. Pseudoternary phase diagrams were obtained and the systems were characterized by using surface tension measurements, particle size determination and scanning electron microscopy (SEM). The concentrations of metal ions before and after extraction were determined by atomic absorption spectrometry. The extraction study of Cu+2 and Ni+2 in the WIII domain contributed to a better understanding of microemulsion extraction, elucidating the various behaviors presented in the literature for these systems. Furthermore, since WIII systems presented high extraction efficiencies, similar to the ones presented by Winsor II systems, they represented an economic and technological advantage in heavy metal extraction due to a small amount of surfactant and cosurfactant used in the process and also due to the formation of a reduced volume of aqueous phase, with high concentration of metal. Considering the reextraction process, it was observed that WIII system is more effective because it is performed in the oil phase, unlike reextraction in WII, which is performed in the aqueous phase. The presence of the metalsurfactant complex in the oil phase makes possible to regenerate only the surfactant present in the organic phase, and not all the surfactant in the process, as in WII system. This fact allows the reuse of the microemulsion phase in a new extraction process, reducing the costs with surfactant regeneration

Síntese de catalisadores nanoporosos na ausência total e parcial de direcionadores orgânicos para pirólise catalítica de óleos pesados e intermediários

The processing of heavy oil produced in Brazil is an emergency action and a strategic plan to obtain self-sufficiency and economic surpluses. Seen in these terms, it is indispensable to invest in research to obtain new catalysts for obtaining light fraction of hydrocarbons from heavy fractions of petroleum. This dissertation for the degree of Doctor of Philosophy reports the materials preparation that combine the high catalytic activity of zeolites with the greater accessibility of the mesoporosity, more particularly the HZSM-5/MCM-41 hybrid, done by synthesis processes with less environmental impact than conventional ones. Innovative methodologies were developed for the synthesis of micro-mesoporous hybrid material by dual templating mechanism and from crystalline zeolitic aluminosilicate in the absence of organic template. The synthesis of hybrid with pore bimodal distribution took place from one-single organic directing agent aimed to eliminate the use of organic templates, acids of any kind or organic solvents like templating agent of crystalline zeolitic aluminosilicate together with temperature-programmed microwave-assisted, making the experimental procedures of preparation most practical and easy, with good reproducibility and low cost. The study about crystalline zeolitic aluminosilicate in the absence of organic template, especially MFI type, is based on use of H2O and Na+ cation playing a structural directing role in place of an organic template. Advanced characterization techniques such as X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Highresolution Transmission Electron Microscopy (HRTEM), Adsorption of N2 and CO2, kinetic studies by Thermogravimetric Analysis (TGA) and Pyrolysis coupled to Gas Chromatography/Mass Spectrometry (Pyrolysis-GC/MS) were employed in order to evaluate the synthesized materials. Achieve the proposed objectives, has made available a set of new methodologies for the synthesis of zeolite and hybrid micro-mesoporous material, these suitable for catalytic pyrolysis of heavy oils aimed at producing light fraction

Estudo evolutivo das condições ambientais da região costeira do município de Guamaré - RN

The work concerns on the evolutionary study of the environmental conditions of the coastal area of Guamaré-RN, where was investigated the geo-environmental transformation occourred in this region, whose primordial purpose was to diagnose the changes verified in the temporary space of five decades (1950 to 2001). With the objective of evaluanting the action of the active coastal processes (currents, waves, tides and winds), in order to understand the generating mechanisms of the erosion/sedimentation, evidenced by constant morphologic changes. The adopted methodological procedure consisted of a succession of stages, involving bibliographical and cartographic study, aereal photographs study, digital treatment of images, field work (sample collection, beaches profiles, characterization of the beach environment and morfodynamics), mapping correction and laboratory analyses (granulometry). The evolutionary study of the morphologic features indicated significant variations in the studied period, mainly, in the dunes, sea terraces, variation of the shore line and tidal flat, evidencing the largest transformations in the temporary space between 1988 and 2001. The analyses of the beach profiles showed a sedimentation tendency in the area of the profiles P1, P2 and P3, however in the monitored pediod, it was observed in the referred profiles, erosive and depositionals intervals evidencing a need of more effective monitoring. The results of the granulometric analyses indicate a predominance of mean to coarse sand in the backshore and estirancy area, as in the shoreface, the analyses indicated medium to fine sand. The morfodynamic state, showed that beach of Minhoto is intermediate state, with alternancy to reflective. The areas of larger vulnerability and sensibility are the tidal flat, shore line, barrier island and mobile dunes, that actually is suffering great environmental impact with expansion of the carcinoculture, urban presence and natural impacts (erosion of the shoreline)

Estimativa da profundidade do embasamento na bacia potiguar usando inversão gravimétrica

The gravity inversion method is a mathematic process that can be used to estimate the basement relief of a sedimentary basin. However, the inverse problem in potential-field methods has neither a unique nor a stable solution, so additional information (other than gravity measurements) must be supplied by the interpreter to transform this problem into a well-posed one. This dissertation presents the application of a gravity inversion method to estimate the basement relief of the onshore Potiguar Basin. The density contrast between sediments and basament is assumed to be known and constant. The proposed methodology consists of discretizing the sedimentary layer into a grid of rectangular juxtaposed prisms whose thicknesses correspond to the depth to basement which is the parameter to be estimated. To stabilize the inversion I introduce constraints in accordance with the known geologic information. The method minimizes an objective function of the model that requires not only the model to be smooth and close to the seismic-derived model, which is used as a reference model, but also to honor well-log constraints. The latter are introduced through the use of logarithmic barrier terms in the objective function. The inversion process was applied in order to simulate different phases during the exploration development of a basin. The methodology consisted in applying the gravity inversion in distinct scenarios: the first one used only gravity data and a plain reference model; the second scenario was divided in two cases, we incorporated either borehole logs information or seismic model into the process. Finally I incorporated the basement depth generated by seismic interpretation into the inversion as a reference model and imposed depth constraint from boreholes using the primal logarithmic barrier method. As a result, the estimation of the basement relief in every scenario has satisfactorily reproduced the basin framework, and the incorporation of the constraints led to improve depth basement definition. The joint use of surface gravity data, seismic imaging and borehole logging information makes the process more robust and allows an improvement in the estimate, providing a result closer to the actual basement relief. In addition, I would like to remark that the result obtained in the first scenario already has provided a very coherent basement relief when compared to the known basin framework. This is significant information, when comparing the differences in the costs and environment impact related to gravimetric and seismic surveys and also the well drillings