Desenvolvimento de metodologias analíticas alternativas por cromatografia gasosa para análise de biodiesel

Since the beginning of the National Program for Production and Use of Biodiesel in Brazil, in 2004, different raw materials were evaluated for biodiesel production, trying to combine the agricultural diversity of the country to the desire to reduce production coasts. To determine the chemical composition of biodiesel produced from common vegetables oils, international methods have been used widely in Brazil. However, for analyzing biodiesel samples produced from some alternative raw materials analytical problems have been detected. That was the case of biodiesel from castor oil. Due the need to overcome these problems, new methodologies were developed using different chromatographic columns, standards and quantitative methods. The priority was simplifying the equipment configuration, realizing faster analyses, reducing the costs and facilitating the routine of biodiesel research and production laboratories. For quantifying free glycerin, the ethylene glycol was used in instead of 1,2,4-butanetriol, without loss of quality results. The ethylene glycol is a cheaper and easier standard. For methanol analyses the headspace was not used and the cost of the equipment used was lower. A detailed determination of the esters helped the deeper knowledge of the biodiesel composition. The report of the experiments and conclusions of the research that resulted in the development of alternative methods for quality control of the composition of the biodiesel produced in Brazil, a country with considerable variability of species in agriculture, are the goals of this thesis and are reported in the following pages

Projeto, construção e análise de um prototipo vibracional em escala de bancada aplicável ao tratamento de água de produção de petróleo bruto, mediante inovadora operação híbrida de adsorção e auto-flotação

A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity

Avaliação da atividade antimalárica de extratos obtidos de algas marinhas no litoral do Rio Grande do Norte

Malaria is a major parasitic disease worldwide, accounting for about 500 million cases and causing 2 million to 3 million deaths annually. Four species are responsible for transmitting this disease to humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium ovale. The parasite resistance to antimalarial drugs and the usual limitations of the vector control implications are contributing to the spread of the disease. The most of significant advances in the search for new antimalarial drugs is based on natural components, the main ones being currently used antimalarial drugs derived from plants. Research on natural products of marine origin (particularly algae) show that some species possess antiplasmodial activity. Knowing that the coast of Rio Grande do Norte is home to several species of algae, the present study was to evaluate, for the first time, the antimalarial activity of ethanolic extracts of seaweed Spatoglossum schroederi, Gracilaria birdiae and Udotea flabellum against Plasmodium falciparum 3D7 strain tests and in vitro using the murine model (Plasmodium berghei) for evaluation in vivo. These species were ground, macerated with ethanol for 24 hours and the extracts concentrated in rotaevaporador (45 ° C ± 5 ° C). For in vitro tests, the extracts were diluted and tested at concentrations between 100 and 1.56 μg/ml (seven concentrations in triplicate), in order to obtain IC50 of each extract. The cytotoxicity tests with macrophages and BGM were performed using the MTT colorimetric assay. BGM macrophages and cells were distributed in 96 wells per plate (1x 105 to macrophages and 1x104 cells per well for BGM) and incubated for 24h at 37 ° C. The ethanol extracts were diluted and tested at concentrations of 100 to 1,56 μg/ml (seven concentrations in triplicate). After periods of 24 hours of incubation with the extracts, 100 μg of MTT was added to each well, and 3 hours elapsed, the supernatant was removed and added 200 μl of DMSO in each well. The absorbance of each well was obtained by reading on a spectrophotometer at 570 nm filter. To evaluate the acute toxicity in vivo, Swiss mice received a single dose (oral) 2000 mg/kg/animal of each extract tested. The parameters of acute toxicity were observed for 8 days. For in vivo tests, Swiss mice were inoculated with 1x105 erythrocytes infected with P. berghei. The treatment was given first to fourth day after infection with 0.2 ml of the extracts in doses of 1000 and 500 mg//g animal. The negative control group received 0.2 ml of 2% Tween-20, whereas the positive control group received sub-dose of chloroquine (5 mg/kg/animal). The assessment of antimalarial activity was done by suppressing suppressing the parasitemia at 5 and 7 days after infection. The growth inhibition of parasites was determined relative to negative control (% inhibition = parasitaemia in control - parasitemia in sample / parasitemia control x 100), the mortality of animals was monitored daily for 30 days The results showed that algae Spatoglossum schroederi and Udotea flabellum showed antimalarial activity in vitro, with reduced parasitemia of 70.54% and 54, respectively. The extracts of the three algae tested showed moderate to high cytotoxicity. Algae S. schroederi and U. flabellum were active against P. berghei only at doses of 500 mg / kg with reduction ranging from 54.58 to 52.65% for the fifth day and from 32.24 to 47.34% for the seventh day, respectively. No toxicity was observed in vivo at the dose tested, over the 8 days of observation. Although preliminary data, the bioactive components in those possible seaweed may be promising for the development of new anti-malarial drugs

O princípio constitucional da eficiência aplicado à outorga e à cobrança da água produzida na exploração petrolífera

Water production is unavoidable during a petrol well s lifetime. The amount of produced water associated with oil varies a lot. It can reach values which account to 50% in volume up to nearly 100%, at the end of the well s economic life. It could be verified that, once the water reaches the productive wells, there must be a management of this produced water. Its destiny is defined after a precise study, after which the best option is chosen between relieving it into the environment, re-injecting it into the producing container or disposing it into non-producing formations. Whichever option is made by the involved professionals, after the necessary analysis, it shall consider, besides the technical and economical aspects, also the alternatives which entail less environmental impact. The purpose of the present research is to conduct a study about the application of the constitutional principle of efficiency on the instruments worked out by the public administration on water management, specifically the water use licence and charging for the use in the management of water resources applicable to water production at the petrol wells. In this attempt, before entering the proper approach of the efficiency of the mentioned instruments, it was necessary not only bring to light the doctrinal perception about the constitutional principle of administrative efficiency, but also make some considerations concerning to the structure of the national water resources management, set by the Federal Constitution (1988) and the federal legislation (9433/97)

Acidentes de Trabalho : análise em profissionais de enfermagem que atuam nas unidades de terapia intensiva e urgência Natal/RN

It is a descriptive-exploratory research, with a quantitative approach, aiming to characterize typical occupational accident suffered by the professionals from nursery group, in the Intensive Care Units and Emergency in a hospital in Natal-RN, trying to identify the factors that contribute to those accidents; to identify some information taken by those professionals related to the accident risks; to know the procedures taken after each accident. This sample is composed by 176 professionals that are 44 nurses and 132 nursing technicians/auxiliaries, collected from March to April 2010. The results related to the personal characterization of the nursery group showed that 31 (18.61%) are between the 36-40 years of age; 148 (84.09%) females and 96 (55.68%) had finished High School. Related to the professional characterization, 53 (30.11%) are nurses, and 123 (69.88%) nursing technicians and auxiliaries; 44 (25.00%) are working as nurses, and 132 (75.00%) as nursing technicians and auxiliaries; 45 (25.56%) are working in the nursery area between 15 to 20 years and 11 months; 53 (30.11%) are in this institution between 10 to 14 years and 11 months; 79 (44.88%) work in the ICU; 55 (31.25%) are working in this area from 1 to 4 years and 11 months; 110 (62.50%) like to work in this area; 161 (91.47%) work 30 to 40 hours per week; 90 (51,13%) have another employment. Related to knowledge about typical occupational accident, 167 (94.88%) said they know about it; 96 (54.54%) know the accident rules; 103 (58.52%) think it is important to talk about this subject in the nursery courses; 92 (52.27%) said this subject is important to be discussed in the work and 372 (87.73%) think education is necessary to reduce accident. Related to the data about accidents, 104 (59.09%) have suffered typical occupational accident, among them 69 (39.20%) have suffered it once; 47 (36.19%) did not register any accident; 60 (57.69%) were caring some patient during the accident; 47 (45.19%) of them occurred in the ICU; 50 (48.07%) professionals were working during the night period; 69 (66.34%) have suffered perforation; 86 (82.69%) had upper limbs affected; 64 (61.53%) were affected by needle; about the reason of the accident, 89 (60.54%) said it occurred due to carelessness. Related to the accident evolution, 88 (85.57%) did not need to remain off work after accident; 13 (81.25%) remained off work during 15 days; 87 (83.65%) had no sequelae and for 101 (97.11%) it was not necessary rehabilitation. We conclude that typical occupational accident can occur with young workers who admit a knowledge about the subject, however they do almost nothing to prevent it. We believe this research has contributed to the characterization of this kind of accident suffered by the nursery group of a public hospital in Natal, and it can stimulate the creation and reformulation of personal protection against typical occupational accident suffered by nursery professionals

Ajuste automático e otimização do tempo de espera (Idle time) em bombeio mecânico de petróleo

The present work presents an algorithm proposal, which aims for controlling and improving idle time to be applied in oil production wells equipped with beam pump. The algorithm was totally designed based on existing papers and data acquired from two Potiguar Basin pilot wells. Oil engineering concepts such as submergence, pump off, Basic Sediments and Water (BSW), Inflow Performance Relationship (IPR), reservo ir pressure, inflow pressure, among others, were included into the algorithm through a mathematical treatment developed from a typical well and then extended to the general cases. The optimization will increase the well production potential maximum utilization having the smallest number of pumping unit cycles directly reflecting on operational cost and electricity consumption reduction

Projeto de um sistema emulador de escoamentos e vaso de separação primária

The purpose of this study was to develop a pilot plant which the main goal is to emulate a flow peak pressure in a separation vessel. Effect similar that is caused by the production in a slug flow in production wells equipped with the artificial lift method plunger lift. The motivation for its development was the need to test in a plant on a smaller scale, a new technique developed to estimate the gas flow in production wells equipped with plunger lift. To develop it, studies about multiphase flow effects, operation methods of artificial lift in plunger lift wells, industrial instrumentation elements, control valves, vessel sizing separators and measurement systems were done. The methodology used was the definition of process flowcharts, its parameters and how the effects needed would be generated for the success of the experiments. Therefore, control valves, the design and construction of vessels and the acquisition of other equipment used were defined. One of the vessels works as a tank of compressed air that is connected to the separation vessel and generates pulses of gas controlled by a on/off valve. With the emulator system ready, several control experiments were made, being the control of peak flow pressure generation and the flow meter the main experiments, this way, it was confirmed the efficiency of the plant usage in the problem that motivated it. It was concluded that the system is capable of generate effects of flow with peak pressure in a primary separation vessel. Studies such as the estimation of gas flow at the exit of the vessel and several academic studies can be done and tested on a smaller scale and then applied in real plants, avoiding waste of time and money.

Desenvolvimento de uma ferramenta computacional para aplicação em métodos de elevação por bombeio centrífugo submerso

The Electrical Submersible Pump (ESP) has been one of the most appropriate solutions for lifting method in onshore and offshore applications. The typical features for this application are adverse temperature, viscosity fluids and gas environments. The difficulties in equipments maintenance and setup contributing to increasing costs of oil production in deep water, therefore, the optimization through automation can be a excellent approach for decrease costs and failures in subsurface equipment. This work describe a computer simulation related with the artificial lifting method ESP. This tool support the dynamic behavior of ESP approach, considering the source and electric energy transmission model for the motor, the electric motor model (including the thermal calculation), flow tubbing simulation, centrifugal pump behavior simulation with liquid nature effects and reservoir requirements. In addition, there are tri-dimensional animation for each ESP subsytem (transformer, motor, pump, seal, gas separator, command unit). This computer simulation propose a improvement for monitoring oil wells for maximization of well production. Currenty, the proprietaries simulators are based on specific equipments manufactures. Therefore, it is not possible simulation equipments of another manufactures. In the propose approach there are support for diverse kinds of manufactures equipments

Enumeração de espectro de distâncias de esquemas de modulação codificada em treliça empregando codificação turbo

In this work, a performance analysis of transmission schemes employing turbo trellis coded modulation. In general, the performance analysis of such schemes is guided by evaluating the error probability of these schemes. The exact evaluation of this probability is very complex and inefficient from the computational point of view, a widely used alternative is the use of union bound of error probability, because of its easy implementation and computational produce bounds that converge quickly. Since it is the union bound, it should use to expurge some elements of distance spectrum to obtain a tight bound. The main contribution of this work is that the listing proposal is carried out from the puncturing at the level of symbol rather than bit-level as in most works of literature. The main reason for using the symbol level puncturing lies in the fact that the enummerating function of the turbo scheme is obtained directly from complex sequences of signals through the trellis and not indirectly from the binary sequences that require further binary to complex mapping, as proposed by previous works. Thus, algorithms can be applied through matrix from the adjacency matrix, which is obtained by calculating the distances of the complex sequences of the trellis. This work also presents two matrix algorithms for state reduction and the evaluation of the transfer function of this. The results presented in comparisons of the bounds obtained using the proposed technique with some turbo codes of the literature corroborate the proposition of this paper that the expurgated bounds obtained are quite tight and matrix algorithms are easily implemented in any programming software language

Desenvolvimento de um simulador de bombeio por cavidades progressivas

The method of artificial lift of progressing cavity pump is very efficient in the production of oils with high viscosity and oils that carry a great amount of sand. This characteristic converted this lift method into the second most useful one in oil fields production. As it grows the number of its applications it also increases the necessity to dominate its work in a way to define it the best operational set point. To contribute to the knowledge of the operational method of artificial lift of progressing cavity pump, this work intends to develop a computational simulator for oil wells equipped with an artificial lift system. The computational simulator of the system will be able to represent its dynamic behavior when submitted to the various operational conditions. The system was divided into five subsystems: induction motor, multiphase flows into production tubing, rod string, progressing cavity pump and annular tubing-casing. The modeling and simulation of each subsystem permitted to evaluate the dynamic characteristics that defined the criteria connections. With the connections of the subsystems it was possible to obtain the dynamic characteristics of the most important arrays belonging to the system, such as: pressure discharge, pressure intake, pumping rate, rod string rotation and torque applied to polish string. The shown results added to a friendly graphical interface converted the PCP simulator in a great potential tool with a didactic characteristic in serving the technical capability for the system operators and also permitting the production engineering to achieve a more detail analysis of the dynamic operational oil wells equipped with the progressing cavity pump

Uma arquitetura para sistemas supervisórios industriais e sua aplicação em processos de elevação artificial de petróleo

The using of supervision systems has become more and more essential in accessing, managing and obtaining data of industrial processes, because of constant and frequent developments in industrial automation. These supervisory systems (SCADA) have been widely used in many industrial environments to store process data and to control the processes in accordance with some adopted strategy. The SCADA s control hardware is the set of equipments that execute this work. The SCADA s supervision software accesses process data through the control hardware and shows them to the users. Currently, many industrial systems adopt supervision softwares developed by the same manufacturer of the control hardware. Usually, these softwares cannot be used with other equipments made by distinct manufacturers. This work proposes an approach for developing supervisory systems able to access process information through different control hardwares. An architecture for supervisory systems is first defined, in order to guarantee efficiency in communication and data exchange. Then, the architecture is applied in a supervisory system to monitor oil wells that use distinct control hardwares. The implementation was modeled and verified by using the formal method of the Petri networks. Finally, experimental results are presented to demonstrate the applicability of the proposed solution

Efeito de adições poliméricas na aderência de pastas de cimento a tubos metálicos após ciclagem térmica

Thermal recovery methods, especially steam injection, have been used to produce heavy oils. However, these methods imply that the metallic casing-cement sheath interface is submitted to thermal cycling. As a consequence, cracking may develop due to the thermal expansion mismatch of such materials, which allows the flow of oil and gas through the cement sheath, with environmental and economical consequences. It is therefore important to anticipate interfacial discontinuities that may arise upon Thermal recovery. The present study reports a simple alternative method to measure the shear strength of casing-sheath interfaces using pushthrough geometry, applied to polymer-containing hardened cement slurries. Polyurethane and recycled tire rubber were added to Portland-bases slurries to improve the fracture energy of intrinsically brittle cement. Samples consisting of metallic casing sections surrounded by hardened polymer-cement composites were prepared and mechanically tested. The effect of thermal cycles was investigated to simulate temperature conditions encountered in steam injection recovery. The results showed that the addition of polyurethane significantly improved the shear strength of the casing-sheath interface. The strength values obtained adding 10% BWOC of polyurethane to a Portland-base slurry more than doubled with respect to that of polyurethane-free slurries. Therefore, the use of polyurethane significantly contributes to reduce the damage caused by thermal cycling to cement sheath, improving the safety conditions of oil wells and the recovery of heavy oils

Simulação computacional do escoamento em bombas de cavidades progressivas

The use of Progressing Cavity Pumps (PCPs) in artificial lift applications in low deep wells is becoming more common in the oil industry, mainly, due to its ability to pump heavy oils, produce oil with large concentrations of sand, besides present high efficiency when compared to other artificial lift methods. Although this system has been widely used as an oil lift method, few investigations about its hydrodynamic behavior are presented, either experimental or numeric. Therefore, in order to increase the knowledge about the BCP operational behavior, this work presents a novel computational model for the 3-D transient flow in progressing cavity pumps, which includes the relative motion between rotor and stator, using an element based finite volume method. The model developed is able to accurately predict the volumetric efficiency and viscous looses as well as to provide detailed information of pressure and velocity fields inside the pump. In order to predict PCP performance for low viscosity fluids, advanced turbulence models were used to treat, accurately, the turbulent effects on the flow, which allowed for obtaining results consistent with experimental values encountered in literature. In addition to the 3D computational model, a simplified model was developed, based on mass balance within cavities and on simplification on the momentum equations for fully developed flow along the seal region between cavities. This simplified model, based on previous approaches encountered in literature, has the ability to predict flow rate for a given differential pressure, presenting exactness and low CPU requirements, becoming an engineering tool for quick calculations and providing adequate results, almost real-time time. The results presented in this work consider a rigid stator PCP and the models developed were validated against experimental results from open literature. The results for the 3-D model showed to be sensitive to the mesh size, such that a numerical mesh refinement study is also presented. Regarding to the simplified model, some improvements were introduced in the calculation of the friction factor, allowing the application fo the model for low viscosity fluids, which was unsuccessful in models using similar approaches, presented in previous works

Modelagem dinâmica do escoamento de um sistema de elevação por plunger lift

A critical problem in mature gas wells is the liquid loading. As the reservoir pressure decreases, gas superficial velocities decreases and the drag exerted on the liquid phase may become insufficient to bring all the liquid to the surface. Liquid starts to drain downward, flooding the well and increasing the backpressure which decreases the gas superficial velocity and so on. A popular method to remedy this problem is the Plunger Lift. This method consists of dropping the "plunger"to the bottom of the tubing well with the main production valve closed. When the plunger reaches the well bottom the production valve is opened and the plunger carry the liquid to the surface. However, models presented in literature for predicting the behavior in plunger lift are simplistic, in many cases static (not considering the transient effects). Therefore work presents the development and validation of a numerical algorithm to solve one-dimensional compressible in gas wells using the Finite Volume Method and PRIME techniques for treating coupling of pressure and velocity fields. The code will be then used to develop a dynamic model for the plunger lift which includes the transient compressible flow within the well

Avaliação da temperatura de cristalização da parafina em sistemas: parafina, solvente e tensoativo

The formation of paraffin deposits is common in the petroleum industry during production, transport and treatment stages. It happens due to modifications in the thermodynamic variables that alter the solubility of alkanes fractions present in petroleum. The deposition of paraffin can provoke significant and growing petroleum losses, arriving to block the flow, hindering to the production. This process is associated with the phases equilibrium L-S and the stages and nucleation, growth and agglomeration the crystals. That process is function of petroleum intrinsic characteristics and temperature and pressure variations, during production. Several preventive and corrective methods are used to control the paraffin crystallization, such as: use of chemical inhibitors, hot solvents injection, use of termochemistry reactions, and mechanical removal. But for offshore exploration this expensive problem needs more investigation. Many studies have been carried through Wax Appearance Temperature (WAT) of paraffin; therefore the formed crystals are responsible for the modification of the reologics properties of the oil, causing a lot off operational problems. From the determination of the WAT of a system it is possible to affirm if oil presents or not trend to the formation of organic deposits, making possible to foresee and to prevent problems of wax crystallization. The solvent n-paraffin has been widely used as fluid of perforation, raising the production costs when it is used in the removal paraffin deposits, needing an operational substitute. This study aims to determine the WAT of paraffin and the interference off additives in its reduction, being developed system paraffin/solvent/surfactant that propitiates the wax solubilization. Crystallization temperatures in varied paraffin concentrations and different solvents were established in the first stage of the experiments. In the second stage, using the methodology of variation of the photoelectric signal had been determined the temperature of crystallization of the systems and evaluated the interferences of additives to reduction of the WAT. The experimental results are expressed in function of the variations of the photoelectric signals during controlled cooling, innovating and validating this new methodology to determine WAT, relatively simple with relation the other applied that involve specific equipments and of high cost. Through the curves you differentiate of the results had been also identified to the critical stages of growth and agglomeration of the crystals that represent to the saturation of the system, indicating difficulties of flow due to the increase of the density