59 resultados para Microemulsion. EOR. Acrylamide. Polyacrylamide


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The produced water is a byproduct formed due to production of petroleum and carries with it a high amount of contaminants such as oil particles in suspension, organic compounds and metals. Thus, these latter pollutants are very difficult to treat because of its high solubility in water. The objective of this work is to use and evaluate a microemulsioned system to remove metals ( K , Mg , Ba , Ca , Cr , Mn , Li , Fe ) of synthetic produced water. For the extraction of metals, it was used a pseudoternary diagram containing the following phases: synthetic produced water as the aqueous phase (AP), hexane as organic phase (OP), and a cosurfactant/surfactant ratio equal to four (C/S = 4) as the third phase, where the OCS (saponified coconut oil) was used as surfactant and n-butanol as cosurfactant. The synthetic produced water was prepared in a bench scale and the region of interest in the diagram for the removal of metals was determined by experimental design called. Ten points located in the phase Winsor II were selected in an area with a large amount of water and small amounts of reagents. The samples were analyzed in atomic absorption spectrometer, and the results were evaluated through a statistical assesment, allowing the efficiency analysis of the effects and their interactions. The results showed percentages of extraction above 90% for the metals manganese, iron, chromium, calcium, barium and magnesium, and around 45% for metals lithium and potassium. The optimal point for the simultaneous removal of metals was calculated using statistical artifact multiple response function (MR). This calculation showed that the point of greatest extraction of metals occurs was the J point, with the composition [72% AP, 9% OP, 19% C/S], obtaining a global extraction percentage about 80%. Considering the aspects analyzed, the microemulsioned system has shown itself to be an effective alternative in the extraction of metals on synthetic produced water remediation

Relevância:

10.00% 10.00%

Publicador:

Resumo:

As rochas carbonáticas ocupam, numa visão global, um expressivo volume da crosta terrestre. De maneira geral, pode-se dizer que essas rochas estão presentes nas diversas unidades litoestatigráficas da Terra. Os reservatórios carbonáticos são reservas naturalmente fraturadas que exigem uma abordagem diferenciada na modelagem em programas de simulação numérica. Os modelos de dupla porosidade são descritos por funções de tranferências que modelam o fluxo de óleo entre matriz e fraturas. Em um reservatório carbonático naturalmente fraturado o sistema de fraturas é determinante no escoamento de fluidos dentro da reserva. Os maiores reservatórios carbonáticos do mundo estão situados no Oriente Médio e na América do Norte. As maiores reservas de óleo brasileiras encontradas neste tipo de reservatório estão localizadas nos campos do Pré-Sal. No Pré-Sal, um volume significativo de dióxido de carbono é produzido juntamente com o óleo. A disponibilidade de um volume consideravél de dióxido de carbono derivado da produção de óleo no Pré-Sal favorece a utilização dos processos de EOR (Enhanced Oil Recovery) por injeção de gás. O processo de injeção de dióxido de carbono vem sendo utilizado em uma grande quantidade de projetos pelo mundo. A afinidade existente entre o óleo e o dióxido de carbono causa uma frente miscível entre as duas fases causando inchamento e vaporização do óleo dentro do reservatório. Para o estudo, foi utilizado um modelo base de reservatório de dupla-porosidade, desenvolvido pela CMG para o 6° Projeto de Soluções Comparativas da SPE, que modela sistemas de fraturas e de matriz e a tranferência de massa fluida entre elas, características de reservatórios naturalmente fraturados. Foi feita uma análise da injeção de diferentes vazões de dióxido de carbono no modelo base e em modelos semelhantes, com aumento e redução de 5 e 0.5 pontos nas propriedades de porosidade e permeabilidade da matriz, respectivamente, tendo a produção de óleo como resultado. A injeção de 25 milhões de pés cúbicos por dia de CO2 foi a vazão que obteve a melhor fator de recuperação

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Actually in the oil industry biotechnological approaches represent a challenge. In that, attention to metal structures affected by electrochemical corrosive processes, as well as by the interference of microorganisms (biocorrosion) which affect the kinetics of the environment / metal interface. Regarding to economical and environmental impacts reduction let to the use of natural products as an alternative to toxic synthetic inhibitors. This study aims the employment of green chemistry by evaluating the stem bark extracts (EHC, hydroalcoholic extract) and leaves (ECF, chloroform extract) of plant species Croton cajucara Benth as a corrosion inhibitor. In addition the effectiveness of corrosion inhibition of bioactive trans-clerodane dehydrocrotonin (DCTN) isolated from the stem bark of this Croton was also evaluated. For this purpose, carbon steel AISI 1020 was immersed in saline media (3,5 % NaCl) in the presence and absence of a microorganism recovered from a pipeline oil sample. Corrosion inhibition efficiency and its mechanisms were investigated by linear sweep voltammetry and electrochemical impedance. Culture-dependent and molecular biology techniques were used to characterize and identify bacterial species present in oil samples. The tested natural products EHC, ECF and DCTN (DMSO as solvent) in abiotic environment presented respectively, corrosion inhibition efficiencies of 57.6% (500 ppm), 86.1% (500 ppm) and 54.5% (62.5 ppm). Adsorption phenomena showed that EHC best fit Frumkin isotherm and ECF to Temkin isotherm. EHC extract (250 ppm) dissolved in a polar microemulsion system (MES-EHC) showed significant maximum inhibition efficiency (93.8%) fitting Langmuir isotherm. In the presence of the isolated Pseudomonas sp, EHC and ECF were able to form eco-compatible organic films with anti-corrosive properties

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Human Papillomavirus (HPV) infection is the major sexually transmitted disease all over the world. There are many factors associated to infection and the virus persistency in the organism. This study aims to evaluate the women's knowledge, attitudes and practice about the Papanicolaou test (Pap), as well as analyze the HPV and Chlamydia trachomatis infections prevalences in sexually active women from the city of São José do Mipibu/RN/Brazil. This research was divided in two steps (step I and step II), using different methodologies and samples each. The samples collected in each step, even socio-demographic or from uterus cervix, are from different patients e were analyzed separated. In step I was evaluated 267 rural and urban zone women s knowledge, attitudes and practices about the Pap by home interview. In the step II were included 605 women with age ranged from 15 to 71 years old, with mean of 33,5 years old and from each one were collected two cervical samples, one for Pap and other for molecular biology, beside the epidemiological interview to investigate the correlation between prevalence of HPV infection and risk factors. To molecular analyses, the samples were processed using a mammal rapid DNA extraction technique protocol. For C. trachomatis DNA detection were used the CP24/27 primers, and GP5+/GP6+ to HPV. PCR products were analyzed by electrophoresis on 8% polyacrylamide gels, followed by silver staining. The results of the step I showed that, in spite of only 46,1% of the interviewed women they have demonstrated to possess appropriate knowledge on the Pap test, the attitude and practice proportions were significantly larger, 63,3% and 64,4% respectively. The largest education degree presented association with adaptation of the knowledge, attitudes and practice, while neglect, lack of solicitation of the exam for the doctor and shame, came as main barriers for the accomplishment of the exam. In the stage II the HPV general prevalence was 28,9%, being 26,7% in the women with normal cytology or benign alterations, 26,7% in the ones that had atypical squamous cells of undetermined significance (ASC-US) and 80% in those with Low grade squamous intraepithelial lesion (LSIL). the HPV infection prevalence was larger in the patients with up to 30 years of age and in the unmarried women, and those that had more than one sexual partner presented larger infection risk. The results show that the sexual relationship with multiple partners increased the infection risk for HPV and consequently the possibility of the occurrence of lesions uterine cervix

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Several pharmaceutical products have been developed in recent years aiming to enhance the treatment of diseases by increasing the effectiveness of drugs. Many of these new products are based on new drug delivery systems. Among these, microemulsions, which were first studied in 1943 by Hoar and Schulman, is of great interest. Microemulsion can be defined as a thermodynamically stable, isotropic, translucent and transparent system of two immiscible liquids stabilized by a surfactant film located in the oil / water interface. The aim os this work was the incorporation of Amphotericin B and Simvasatin to a microemulsion system and analyzes its physicochemical properties and their therapeutical activity when incorporated into this system. Some very promising results were achieved as the reduction of the toxicity and maintenance of the efficacy of the Amphotericin B incorpored into a microemulsion, which was demonstrated in the in vitro pharmacotoxicological study. As for the incorporation of Simvastatin in microemulsion, it was observed a significant improvement in the potential antiinflammatory and anti-infective properties when the system was use to treat infected wounds (simvastatin pleiotropic effects). Therefore, it can be concluded that the incorporation of these drugs into microemulsion system reveal the potential of microemulsions as a promising and novel dosage form, qualifying them for future trials in order to make them available in the pharmaceutical market

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The inorganic actives, represented mainly by microfine zinc oxide and titanium dioxide, have shown great potential to protect against large UV spectrum. The aim of this study is the development, characterization and analysis of stability in the short term of microemulsions containing inorganic fotoprotection agents. The microemulsions identified by the phases diagram containing the metallic oxides were produced by two different methods and subjected to the centrifugation test and thermal stress cycles, and subsequently characterized by macroscopic evaluation, test dilution, electrical conductivity, pH, particle size, and zeta potential. This study highlights the influence of the metal oxides addition in the structure and distribution of micelles in the microemulsions

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The development of new fuels is an important field of scientific and technological activities, since much of the energy consumed in the world is obtained from oil, coal and natural gas, and these sources are limited and not renewable. Recently it has assessed the employment of microemulsions as an alternative for obtaining fuel isotropic between phases originally not miscible. Among many advantages, emphasizes the application of substances that provide the reduction of levels of emissions compared to fossil fuels. Thus, this work was a study of various microemulsified systems, aiming to check the performance of the winsor regions front of the use of surfactants: RENEX 18 → 150, UNITOL L-60 → L-100 and AMIDA 60, together with structure of esters from soybean and castor bean oils. From the results it were chosen four systems to physico-chemical analyzes: System I RENEX 60, Soil bean oil, methylic ester (EMOS) and water; System II RENEX 60/AMIDA 60, EMOS and water; System III RENEX 70, mamona oil methylic ester (EMOM) and water and System IV RENEX 95, EMOM and water. The tests of physico-chemical characterization and study of temperature increase were done with nine points with different compositions in a way to include the interest area (microemulsion W/O). After this study, was conducted a modeling to predict the viscosity, the property is more varied as function of compositions systems changes. The best results were the systems II and IV with a temperature stability above 60°C. The system I had its physico-chemical characterization very similar to a fossil fuel. The system II was the best one due to its corrosivity be stable. In the modeling the four systems had shown good, with an error that varied between 5 and 18%, showing to be possible the viscosity prediction from the composition of the system. The effects the microemulsion and the engine´s performance with the microemulsion were also avaliated. The tests were performed in a cycle-diesel engine. The potency and consumption were analysed. Results show a slight increase the rendiment fuel compared with the conventional as well as a decrease in specific consumption

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work presents studies related to the use of microemulsions in the solubilization of heavy crude oil fractions responsible by the formation of deposits. The first stage of the work was addressed to the construction of phases diagrams, with the intention of determining the area within which the microemulsion is formed. The following systems were studied: UNITOL L 90 n-Butanol - Water - Kerosene (system 1); UNITOL L 90 - n-Butanol - Water - Xylene (system 2); UNITOL L 90 n-Butanol - Water - Kerosene/Xylene 10% (system 3); UNITOL L 90 - Sec-Butanol - Water - Xylene (system 4). In parallel experiments of physical adsorption were carried out by the static method, with the intention of simulating natural conditions of reservoirs. Crude oil of the Fazenda Belém field (Rio Grande do Norte), was used as solute, xylene as solvent and the Assu sandstone (Rio Grande do Norte, Brazil) and Botucatu sandstone (Paraná, Brazil) as rock reservoirs. The curves of adsorption presented the S format type, in agreement with the classification proposed by Giles, Smith and Huitson (1974). The solubilization process was accomplished in the batch method, by varying the time of agitation, the microemulsions and the solid/solution ratio. The experiments showed that the microemulsions presented high efficiency in the solubilization of the crude oil adsorbed on the sandstones. System 2 presented an efficiency of 99% for the Assu sandstone and 97% for the Botucatu sandstone

Relevância:

10.00% 10.00%

Publicador:

Resumo:

With the increase of asphalt milling services was also a significant increase in recycling services pavements. The techniques used today are basically physical processes in which the milled material is incorporated into new asphalt mixtures or executed on site, with the addition of virgin asphalt and rejuvenating agent. In this paper seeks to analyze the efficiency of extraction of CAP (Petroleum Asphalt Cement) mixtures from asphalt milling, using commercial solvents and microemulsions. The solvents were evaluated for their ability to solubilize asphalt using an extractor reflux-type apparatus. Pseudoternary diagrams were developed for the preparation of microemulsion O/W surfactant using a low-cost coconut oil saponified (OCS). Microemulsions were used to extract the CAP of asphalt through physicochemical process cold. Analysis was performed concentration of CAP in solution by spectroscopy. The data provided in the analysis of concentration by the absorbance of the solution as the basis for calculating the percentage of extraction and the mass flow of the CAP in the solution. The results showed that microemulsions prepared with low concentration of kerosene and butanol/OCS binary has high extraction power of CAP and its efficiency was higher than pure kerosene, reaching 95% rate of extraction

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Thermal methods made heavy oil production possible in fields where primary recovery failed. Throughout the years steam injection became one of the most important alternatives to increase heavy oil recovery. There are many types of steam injection, and one of them is the cyclic steam injection, which has been used with success in several countries, including Brazil. The process involves three phases: firstly, steam is injected, inside of the producing well; secondly, the well is closed (soak period); and finally, the well is put back into production. These steps constitute one cycle. The cycle is repeated several times until economical production limit is reached. Usually, independent of reservoir type, as the number of cycles increases the cyclic injection turns less efficient. This work aims to analyze rock and reservoir property influence in the cyclic steam injection. The objective was to study the ideal number of cycles and, consequently, process optimization. Simulations were realized using the STARS simulator from the CMG group based in a proposed reservoir model. It was observed that the reservoir thickness was the most important parameter in the process performance, whilst soaking time influence was not significant

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The underground reservoirs of fuel retailing system represent an environmental threat, because once in bad conservation, these tanks allow fuel leakage and infiltration. For soil contaminated with fuel, such as diesel oil, the present study introduces the microemulsion systems used by the method of washing. In tests carried out in column with a sample of sandy soil artificially contaminated and previously characterized as to its void level to porosity, to permeability which is an important parameter concerning the study of the method of washing. While microemulsions were characterized for their viscosity and wettability, a variation of active matter was also done departing from the original formulation. The hydraulic diffusivity of the microemulsion was studied so as the injection of such fluid in a soil with sandy characteristics. The results of the extractions revealed the excellent performance of these systems which get to remove around 95% of diesel fuel. This proves the efficiency of the microemulsion in the process of removal of diesel fuel from the soil with the advantage of being a system easily obtainable and less aggressive to the environment when compared to organic solvents.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The constant search for biodegradable materials for applications in several fields shows that carnauba wax can be a viable alternative in the manufacturing of biolubricants. Carnauba wax is the unique among the natural waxes to have a combination of properties of great importance. In previous studies it was verified the presence of metals in wax composition that can harm the oxidative stability of lubricants. Considering these factors, it was decided to develop a research to evaluate iron removal from carnauba wax, using microemulsion systems (Me) and perform the optimization of parameters, such as: extraction pH, temperature, extraction time, among others. Iron concentration was determined by atomic absorption and, to perform this analysis, sample digestion in microwave oven was used, showing that this process was very efficient. It was performed some analysis in order to characterize the wax sample, such as: attenuated total reflectance infrared spectroscopy (ATR-IR), thermogravimetry (TG), differential scanning calorimetry (DSC), energy dispersive X-ray fluorescence (EDXRF), scanning electron microscopy (SEM) and melting point (FP). The microemulsion systems were composed by: coconut oil as surfactant, n-butanol as cosurfactant, kerosene and/or heptanes as oil phase, distilled water as water phase. The pH chosen for this study was 4.5 and the metal extraction was performed in finite experiments. To evaluate Me extraction it was performed a factorial design for systems with heptane and kerosene as oil phase, also investigating the influence of temperature time and wax/Me ratio, that showed an statistically significant answer for iron extraction at 95% confidence level. The best result was obtained at 60°C, 10 hours contact time and 1: 10 wax/Me ratio, in both systems with kerosene and heptanes as oil phase. The best extraction occurred with kerosene as oil phase, with 54% iron removal

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The large investment in exploration activities offshore Brazil has generated new findings, generally in carbonate reservoirs, with different wettability conditions usually considered in the sandstone, strongly water-wet. In general, the carbonates reservoirs tend to be oil-wet, it difficult to mobilize of oil these reservoirs. These oils can be mobilized by different methods, or it may reverse the wettability of the surface of the reservoir and facilitate the flow of oil, improving production rates. Thus, the objective of this work was to study the influence of inversion on the wettability of the rock in the production and recovery of petroleum from carbonate reservoirs, using microemulsions. Three systems were chosen with different classes of surfactants: a cationic (C16TAB), an anionic (SDS) and nonionic (Unitol L90). Studies of the influence of salinity on the formation of the microemulsion as well as the characterization of fluids using density and viscosity measurements were also performed. To verify the potential of microemulsion systems in changing the wettability state of the chalk oil-wet to water-wet, contact angle measurements were performed using chalk of neutral-wet as surface material. Overall, with respect to the ionic character of the surfactants tested, the cationic surfactant (C16TAB) had a greater potential for reversal in wettability able to transform the rock wettability neutral to strongly water-wet, when compared with the anionic surfactant (SDS) and nonionic (Unitol L90), which showed similar behavior, improving the wettability of the rock to water. The microemulsions of all surfactants studied were effective in oil recovery, resulting in 76.92% for the system with C16TAB, 67.42% for the SDS and 66.30% for Unitol L90 of residual oil

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Environmental Laws and Regulations to dump wastewater are increasingly relevant and, together with pressure from environmentalists, provide awareness of academics in search of solutions. In Brazil, federal law, through Resolution No. 357 of 17/03/05 of the National Environmental Council - CONAMA, in Article 24 deals with the disposal of these effluents. Water pollution with heavy metals is concern because of the difficulty of the treatment and removal from the environment. Copper, for example, is a metallic element and in the form of salt is very soluble in water which dificults its removal. In this context, this study aims to evaluate the extraction of copper with acrylamide polymers through the process of assisted flocculation followed by filtration. Therefore, we used acrylamide polymers, produced by SNF Floerger, with varying degrees of ionicity which is the parameter examined on the extraction of copper. We used the FA polymers FA 920 SH, AH 912 SH, AN 905 SH, AN 910 SH, AN 923 SH, AN 945 SH, AN 956 SH and AN 977 SH, which have anionicities different from each other and growing in that order. The parameters temperature, pH, concentration of the copper solution and stirring speed are fixed. The polymer solution was added to a solution of 200 ppm copper, varying the concentration of polymer. After stirring, an assisted flocculation occurred followed by filtration of the effluent. The filtrate was analyzed by atomic absorption spectrophotometer and the percentage removal of copper ranged from 63 % to 97 %, noting that polymers with higher ionic charge were responsible for the highest percentage of copper extraction. The results of this study showed that these polymers can be applied in the treatment of wastewaters containing metals such as copper

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Petroleum exists in the nature in certain underground formations where it is adsorbed into the rocks pores. For the conventional recovery methods usually only 30% of the oil is extracted and this can be credited, basically, to three aspects: high viscosity of the oil, geology of the formation and high interfacial tensions between the reservoir s fluids. The enhanced recovery methods use the injection of a fluid or fluids mixture in a reservoir to act in points where the conventional process didn't reach the recovery rates. Microemulsion flooding, considered an enhanced method, has the purpose to desorb the oil from the rock formation and to attain an efficient displacement of the oil emulsion. With this in mind, this work was accomplished with two main objectives: the study of the parameters effect that influence a microemulsified system (surfactant and cosurfactant types, C/S rate and salinity) and the evaluation of displacement efficiency with the microemulsions that showed stability in the rich aqueous area. For the analyzed parameters it was chose the microemulsions composition used in the recovery stage: 25% water, 5% kerosene, 46.7% of butanol as cosurfactant and 23.3% of BC or SCO cosurfactant. The core plugs of Assu and Botucatu sandstones were appraised in porosity and permeability tests and then submitted to the steps of saturation with seawater and oil, conventional recovery with water and enhanced recovery with the selected microemulsions. The Botucatu sandstone presented better recovery parameters, and the microemulsion composed with BS surfactant had larger recovery efficiency (26.88%)