1000 resultados para PM3. QTAIM. Tensoativo. Alcenos e recuperação terciária


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present work aims to study the theoretical level of some processes employed in the refining of petroleum fractions and tertiary recovery of this fluid. In the third chapter, we investigate a method of hydrogenation of oil fractions by QTAIM (Quantum Theory of Atoms in Molecules) and thermodynamic parameters. The study of hydrogenation reactions, and the stability of the products formed, is directly related to product improvement in the petrochemical refining. In the fourth chapter, we study the theoretical level of intermolecular interactions that occur in the process of tertiary oil recovery, or competitive interactions involving molecules of non-ionic surfactants, oil and quartz rock where oil is accumulated. Calculations were developed using the semiempirical PM3 method (Parametric Model 3). We studied a set of ten non-ionic surfactants, natural and synthetic origin. The study of rock-surfactant interactions was performed on the surface of the quartz (001) completely hydroxylated. Results were obtained energetic and geometric orientations of various surfactants on quartz. QTAIM was obtained through the analysis of the electron density of interactions, and thus, providing details about the formation of hydrogen bonds and hydrogen-hydrogen systems studied. The results show that the adsorption of ethoxylated surfactants in the rock surface occurs through the hydrogen bonding of the type CH---O, and surfactants derivatives of polyols occurs by OH---O bonds. For structures adsorption studied, the large distance of the surfactant to the surface together with the low values of charge density, indicate that there is a very low interaction, characterizing physical adsorption in all surfactants studied. We demonstrated that surfactants with polar group comprising oxyethylene units, showed the lowest adsorption onto the surface of quartz, unlike the derivatives of polyols

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Goma xantana é um heteropolissacarídeo hidrosolúvel, produzida industrialmente por fermentação da sacarose por Xanthomonas campestris. Suas excelentes propriedades reológicas contribuem para o grande número de aplicações na indústria de alimentos e recuperação terciária de petróleo. Economicamnte a utilização petroquímica não é ainda viável em função do custo da sacarose, o que torna interessante estudar fontes de carbonos alternativas, como é o caso do resíduo do suco de maçã. As cepas de Xanthomonas campestris pv maniothis foram mantidas em agar YM a 4 °C, e o inóculo foi incubado em meio YM. A produção de goma foi realizada nos meios fermentativos I e II, com sacarose como fonte de carbono padrão, e como fonte alternativa o resíduo de maçã fuji. A fermentação em Incubadora/28 °C/150 rpm produziu goma precipitada em álcool. A condição otimizada de 45 g.L-1 de meio II (0,05% uréia, 0,5% de KH2PO4 e 70% de resíduo) representou um rendimento 10 vezes maior do que o obtido com sacarose. Por CG-EM obteve-se 44,53% de manose, 34,76% de glicose e 20,71% de ácido glucurônico para a composição desta goma. O uso de resíduo de maçã para produção de goma xantana é viável porque pode ser usado com um substrato suplementar e apresentar rendimento de goma muito superior ao obtido com sacarose.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Petroleum is a complex combination of various classes of hydrocarbons, with paraffinic, naphtenic and aromatic compounds being those more commonly found in its composition. The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, enhanced recovery methods are cited in applications where conventional techniques have proven to be little effective. The injection of surfactant solutions as an enhanced recovery method is advantageous in that surfactants are able to reduce the interfacial tensions between water and oil, thus augmenting the displacement efficiency and, as a consequence, increasing the recovery factor. This work aims to investigate the effects of some parameters that influence the surfactant behavior in solution, namely the type of surfactant, the critical micelle concentration (CMC) and the surface and interface tensions between fluids. Seawater solutions containing the surfactants PAN, PHN and PJN have been prepared for presenting lower interfacial tensions with petroleum and higher stability under increasing temperature and salinity. They were examined in an experimental apparatus designed to assess the recovery factor. Botucatu (Brazil) sandstone plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The plugs had porosity between 29.6 and 32.0%, with average effective permeability to water of 83 mD. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The tanning industries are those which transform animal hide or skin into leather. Due to the complexity of the transformation process, greater quantities of chemicals are being used which results in the generation of effluents with residual solids. The chromium in the residual waters generated by tanning tend to be a serious problem to the environment, therefore the recovery of this metal could result in the reduction of manufacturing costs. This metal is usually found in a trivalent form which can be converted into a hexavalent compound under acidic conditions and in the presence of organic matter. The present study was carried out with the objective to recover chromium through an extraction/re-extraction process using micro emulsions. Micro emulsions are transparent and thermodynamically stable system composed of two immiscible liquids, one forming the continuous phase and the other dispersed into micro bubbles, established by an interfacial membrane formed by surface active and co-surface active molecules. The process of recovering the chromium was carried out in two stages. The first, an extraction process, where the chromium was extracted in the micro emulsion phase and the aqueous phase in excess was separated. In the second stage, a concentrated acid was added to the micro emulsion phase rich in chromium in order to obtain a Winsor II system, where the water that formed in the micro emulsion phase separates into a new micro emulsion phase with a higher concentration of chromium, due to the lowering of the hydrophiles as well as the ionisation of the system. During the experimental procedure, a study was initiated with a synthetic solution of chromium sulphate passing onto the effluent. A Morris extractor was used in the extraction process. Tests were carried out according to the plan and the results were analysed by statistical methods in order to optimise the main parameters that influence the process: the total rate of flow (Q), stirring speed (w) and solvent rate (r). The results, after optimization, demonstrated that the best percentuals in relation to the chromium extraction (99 %) were obtained in the following operational conditions: Q= 2,0 l/h, w= 425 rpm and r= 0,375. The re-extraction was carried out at room temperature (28 °C), 40 °C and 50°C using hydrochloric acid (8 and 10 M) and sulphuric acid (8 M) as re-extracting agents. The results obtained demonstrate that the process was efficient enough in relation to the chromium extraction, reaching to re-extraction percentage higher than 95 %.

Relevância:

30.00% 30.00%

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:

30.00% 30.00%

Publicador:

Resumo:

The generation of effluent from the finishing process in textile industry is a serious environmental problem and turned into an object of study in several scientific papers. Contamination with dyes and the presences of substances that are toxic to the environment characterize this difficult treatment effluent. Several processes have already been evaluated to remove and even degrade such pollutants are examples: coagulation-flocculation, biological treatment and advanced oxidative processes, but not yet sufficient to enable the recovery of dye or at least of the recovery agent. An alternative to this problem is the cloud point extraction that involves the application of nonionic surfactants at temperatures above the cloud point, making the water a weak solvent to the surfactant, providing the agglomeration of those molecules around the dyes molecules by affinity with the organic phase. After that, the formation of two phases occurred: the diluted one, poor in dye and surfactant, and the other one, coacervate, with higher concentrations of dye and surfactants than the other one. The later use of the coacervate as a dye and surfactant recycle shows the technical and economic viability of this process. In this paper, the cloud point extraction is used to remove the dye Reactive Blue from the water, using nonionic surfactant nonyl phenol with 9,5 etoxilations. The aim is to solubilize the dye molecules in surfactant, varying the concentration and temperature to study its effects. Evaluating the dye concentration in dilute phase after extraction, it is possible to analyze thermodynamic variables, build Langmuir isotherms, determine the behavior of the coacervate volume for a surfactant concentration and temperature, the distribution coefficient and the dye removal efficiency. The concentration of surfactant proved itself to be crucial to the success of the treatment. The results of removal efficiency reached values of 91,38%, 90,69%, 89,58%, 87,22% and 84,18% to temperatures of 65,0, 67,5, 70,0, 72,5 and 75,0°C, respectively, showing that the cloud point extraction is an efficient alternative for the treatment of wastewater containing Reactive Blue

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Environmental sustainability has become one of the topics of greatest interest in industry, mainly due to effluent generation. Phenols are found in many industries effluents, these industries might be refineries, coal processing, pharmaceutical, plastics, paints and paper and pulp industries. Because phenolic compounds are toxic to humans and aquatic organisms, Federal Resolution CONAMA No. 430 of 13.05.2011 limits the maximum content of phenols, in 0.5 mg.L-1, for release in freshwater bodies. In the effluents treatment, the liquid-liquid extraction process is the most economical for the phenol recovery, because consumes little energy, but in most cases implements an organic solvent, and the use of it can cause some environmental problems due to the high toxicity of this compound. Because of this, exists a need for new methodologies, which aims to replace these solvents for biodegradable ones. Some literature studies demonstrate the feasibility of phenolic compounds removing from aqueous effluents, by biodegradable solvents. In this extraction kind called "Cloud Point Extraction" is used a nonionic surfactant as extracting agent of phenolic compounds. In order to optimize the phenol extraction process, this paper studies the mathematical modeling and optimization of extraction parameters and investigates the effect of the independent variables in the process. A 32 full factorial design has been done with operating temperature and surfactant concentration as independent variables and, parameters extraction: Volumetric fraction of coacervate phase, surfactant and residual concentration of phenol in dilute phase after separation phase and phenol extraction efficiency, as dependent variables. To achieve the objectives presented before, the work was carried out in five steps: (i) selection of some literature data, (ii) use of Box-Behnken model to find out mathematical models that describes the process of phenol extraction, (iii) Data analysis were performed using STATISTICA 7.0 and the analysis of variance was used to assess the model significance and prediction (iv) models optimization using the response surface method (v) Mathematical models validation using additional measures, from samples different from the ones used to construct the model. The results showed that the mathematical models found are able to calculate the effect of the surfactant concentration and the operating temperature in each extraction parameter studied, respecting the boundaries used. The models optimization allowed the achievement of consistent and applicable results in a simple and quick way leading to high efficiency in process operation.

Relevância:

30.00% 30.00%

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%)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In heavy oil fields there is a great difficulty of the oil to flow from the reservoir to the well, making its production more difficult and with high cost. Most of the original volumes of oil found in the world are considered unrecoverable by the use of the current methods. The injection of micellar solutions has a direct action in the oil interfacial properties, resulting in an enhanced oil recovery. The objective of this research was the study and selection of micellar solutions with ability to decrease the interfacial interactions between fluids and reservoir formation, increasing oil production. The selected micellar solutions were obtained using commercial surfactants and surfactants synthesized in laboratory, based on the intrinsic properties of these molecules, to use in the enhanced oil recovery. Petroleum Reservoirs were simulated using sandstone plugs from Botucatu formation. Experiments with conventional and enhanced oil recovery techniques were accomplished. The obtained results showed that all micellar solutions were able to enhance oil recovery, and the micellar solution prepared with a SB anionic surfactant, at 2% KCl solution, showed the best recovery factor. It was also accomplished an economic analysis with the SB surfactant solution. With the injection of 20% porous volume of micellar solution, followed by brine injection, the increment in petroleum recovery can reach 81% recovery factor in the 3rd porous volume injected. The increment in the total cost by the addition of surfactant to the injection water represents R$ 7.50/ton of injected fluid

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The high concentration of residual oil is one of the greatest problems found in petroleum mature fields. In these reservoirs, different enhanced oil recovery methods (EOR) can be used, highlighting the microemulsion injection. The microemulsion has showed to be efficient in petroleum recovery due to its ability to promote an efficient displacement of the petroleum, acting directly in the residual oil. In this way, this research has as objective the study of microemulsion systems obtained using a commercial surfactant (TP), determining microemulsion thermal stabilities and selecting points inside the pseudoternary phases diagram, evaluating its efficiencies and choosing the best system, that has the following composition: TP as surfactant (S), isopropyl alcohol as co-surfactant (C), kerosene as oil phase, water as aqueous phase, C/S ratio = 1, and 5% sodium p-toluenesulfonate as hydrotope; being observed the following parameters for the selection of the best pseudoternary phases diagram: C/S ratio, co-surfactant nature and addition of hydrotope to the system. The efficiency in petroleum recovery was obtained using two sandstone formation systems: Assu and Botucatu. The study of thermal stabilities showed that as the concentration of active matter in the system increased, the thermal stability also increased. The best thermal stability was obtained using point F (79.56 0C). The system that presented the best recovery percentile between the three selected (3) was composed by: 70% C/S, 2% kerosene and 28% water, with 94% of total recovery efficiency and 60% with microemulsion injection, using the Botucatu formation, that in a general way presented greater efficiencies as compared with the Assu one (81.3% of total recovery efficiency and 38.3% with microemulsion injection)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The drilling fluid used to assist in the drilling operation of oil wells, accumulates solids inherent in the formation as it is circulated in the well, interfering in the fluid performance during operation. It is discarded after use. The disposal of these fluids causes one of the most difficult environmental problems in the world. This study aims to promote liquid phase separation of drilling fluids, which have circulated in oil wells, and enable this recovered liquid to formulate a new fluid. For this, non-ionic surfactants were used in order to select the best outcome in phase separation. Five real water-based drilling fluids were utilized, which were collected directly from the fields of drilling oil wells, classified as polymeric fluids. The methodology used consisted in combining the fluid with surfactant and then subjecting it to a process of centrifugation or decantation. The decantating tests were scheduled through experimental planning 23 and 32, using as variables the percentage (%) of surfactant utilized and the stirring time in minutes. The surfactants used were ethoxylated nonylphenol and lauryl alcohol ethoxylated with different degrees of ethoxylation. Phase separation was monitored first by tests of stability, and subsequently by the height of the interface in beakers of 100 mL. The results showed that from the surfactants studied, the lauryl alcohol ethoxylated with 3 ethoxylation units has been the most effective in the phase separation process of the drilling fluids tested. The statistical tool used was of great industrial value regarding the programming phase separation in drilling fluids. In conclusion, the liquid phase separated using surfactant can be reused for a new formulation of drilling fluid with similar properties of a new fluid, assuring its efficiency. And in the resulting analysis it is also suggested that the adsorption is the mechanism that leads the phase separation, with surfactant adsorbing in the active solids

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Due to the need of increasing production in reservoirs that are going through production decline, methods of advanced recovery have frequently been used in the last years, as the use of conventional methods has not been successful in solving the problem of oil drifting. In this work, the efficiency of different microemulsionated systems in the flow of oil from cores from Assu and Botucatu formations. Regarding drifting tests, cores were calcinated at a temperature of 1000°C, for 18 hours, with the aim of eliminating any organic compound present in it, increasing the resultant permeability. Following, the cores were isolated with resin, resulting in test specimens with the following dimensions: 3.8 cm of diameter and 8.7 cm of length. Cores were saturated with brine, composed of aqueous 2 wt % KCl, and oil from Guamaré treatment station (Petrobras/RN). A pressure of 20 psi was used in all tests. After core saturation, brine was injected again, followed by oil at constant flow rate. The system S3 - surfactant (anionic surfactant of short chain), isoamillic alcohol, pine oil, and water - presented the best drift efficiency, 81.18%, while the system S1E commercial surfactant, ethyl alcohol, pine oil, and distilled water presented low drift efficiency, 44,68%

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The growing interest and applications of biotechnology products have increased the development of new processes for recovery and purification of proteins. The expanded bed adsorption (EBA) has emerged as a promising technique for this purpose. It combines into one operation the steps of clarification, concentration and purification of the target molecule. Hence, the method reduces the time and the cost of operation. In this context, this thesis aim was to evaluate the recovery and purification of 503 antigen of Leishmania i. chagasi expressed in E. coli M15 and endotoxin removal by EBA. In the first step of this study, batch experiments were carried out using two experimental designs to define the optimal adsorption and elution conditions of 503 antigen onto Streamline chelating resin. For adsorption assays, using expanded bed, it was used a column of 2.6 cm in diameter by 30.0 cm in height coupled to a peristaltic pump. In the second step of study, the removal of endotoxin during antigen recovery process was evaluated employing the non-ionic surfactant Triton X-114 in the washing step ALE. In the third step, we sought developing a mathematical model able to predict the 503 antigen breakthrough curves in expanded mode. The experimental design results to adsorption showed the pH 8.0 and the NaCl concentration of 2.4 M as the optimum adsorption condition. In the second design, the only significant factor for elution was the concentration of imidazole, which was taken at 600 mM. The adsorption isotherm of the 503 antigen showed a good fit to the Langmuir model (R = 0.98) and values for qmax (maximum adsorption capacity) and Kd (equilibrium constant) estimated were 1.95 mg/g and 0.34 mg/mL, respectively. Purification tests directly from unclarified feedstock showed a recovery of 59.2% of the target protein and a purification factor of 6.0. The addition of the non-ionic surfactant Triton X-114 to the washing step of EBA led to high levels (> 99%) of LPS removal initially present in the samples for all conditions tested. The mathematical model obtained to describe the 503 antigen breakthrough curves in Streamline Chelanting resin in expanded mode showed a good fit for both parameter estimation and validation steps. The validated model was used to optimize the efficiencies, achieving maximum values of the process and of the column efficiencies of 89.2% and 75.9%, respectively. Therefore, EBA is an efficient alternative for the recovery of the target protein and removal of endotoxin from an E. coli unclarified feedstock in just one step.