Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-13T16:48:50Z No. of bitstreams: 1 2016 - MATHEUS GOMES SILVA.pdf: 2058072 bytes, checksum: 65bd3fe4a96ed7ef6c405b0ab87a8edd (MD5) / Made available in DSpace on 2017-02-13T16:48:50Z (GMT). No. of bitstreams: 1 2016 - MATHEUS GOMES SILVA.pdf: 2058072 bytes, checksum: 65bd3fe4a96ed7ef6c405b0ab87a8edd (MD5) Previous issue date: 2016-07-27 / The Hidrogen sulfide is one of the substances most dangers in the oil and gas production. The H2S causes great economic losses to industries and so their removal is desired. The use of the triazine to remove the H2S has been extensively documented in the literature. However, the number of products that present the physical and chemical properties desired to act as H2S scavenger, available in the market, is reduced. For this reason, the search by molecules that act in removing of H2S has been the object of research in the worldwide. The goal of this work was investigate the thermal stability of two different H2S scavengers: 1,3,5-tris (hydroxyethyl) hexahydro-s-triazine (commercial) and 1,3,5-tris (hydroxypropyl) hexahydro-s-triazine (synthesized in our laboratory ) when they are subject to processing condition in a pilot plant. To achieve this goal was built a pilot plant capable of simulating some operating conditions of the pre-salt exploration, such as temperature, shear rate and residence time. The thermal stability (degradation) of the triazines was investigated by monitoring the conductivity of the samples. For comparison purposes were performed condutimetry tests of samples in bench tests in the laboratory and pilot plant at temperatures of 30?C, 40?C, 50?C, 60?C and 80?C. For both triazines, the conductivity values obtained in the pilot plant is much higher than those found in bench tests: 65.1 S/cm (2C) and 65.1 S/cm (3C) and 45.5 S/cm (2C), and 32.1 S/cm (3C) respectively. The results showed that the conductivity values are strongly affected by the processing time, being more evident differences in their bench tests. The results of monitoring the conductivity of the samples allowed to verify that the 1,3,5-tris (hydroxyethyl) hexahydro-s-triazine (commercial) and 1,3,5-tris (hydroxypropyl) hexahydro-s- triazine (synthesized in our laboratory) does not undergo degradation under the process conditions which have been subjected, either in bench tests or plant pilot. / O sulfeto de Hidrog?nio ? uma das subst?ncias mais perigosas na produ??o de petr?leo e g?s. O H2S provoca grandes perdas econ?micas para as ind?strias e assim a sua remo??o ? desejada. O uso da triazina para remover o H2S tem sido extensivamente documentado na literatura. No entanto, o n?mero de produtos que apresentam propriedades f?sicas e qu?micas desejadas para actuar como eliminador de H2S, dispon?vel no mercado, ? reduzida. Por esta raz?o, a busca por mol?culas que atuem na remo??o de H2S tem sido o objeto de pesquisa no mundo inteiro. O objectivo deste trabalho foi o de investigar a estabilidade t?rmica de duas diferentes sequestrantes de H2S: 1,3,5-tris (hidroxietil) hexa-hidro-s-triazina (comercial) e 1,3,5-tris (hidroxipropil) hexa-hidro-s-triazina (sintetizada em laborat?rio), quando eles est?o sujeitos a condi??o de processamento em uma planta piloto. Para atingir este objetivo foi constru?da uma planta piloto capaz de simular algumas condi??es de processamento da explora??o do pr?-sal, tais como temperatura, taxa de cisalhamento e tempo de resid?ncia. A estabilidade t?rmica (degrada??o) das triazinas, foi investigada atrav?s da monitoriza??o da condutividade das amostras. Para fins de compara??o foram realizados testes condutimetria de amostras em ensaios de bancada de laborat?rio e na planta piloto nas temperaturas de 30?C, 40?C, 50?C, 60?C e 80?C. Para ambas as triazinas, os valores de condutividade obtidos na instala??o piloto ? muito mais elevado do que aqueles encontrados no banco: 65,1 S/cm (2c) e 65,1 S/cm (3C) e 45,5 S/cm (2C), e 32,1 S/cm (3C), respectivamente. Os resultados mostraram que os valores de condutividade s?o fortemente afetados pelo tempo de processamento, sendo as diferen?as mais evidentes em seus testes de bancada. Os resultados da monitoriza??o da condutividade das amostras permitiram verificar que o 1,3,5-tris (hidroxietil) hexa-hidro-s-triazina (comercial) e 1,3,5-tris (hidroxipropil) hexa-hidro-triazina S- (sintetizado no nosso laborat?rio) n?o sofre degrada??o sob as condi??es de processo que foram sujeitos, tanto em testes de bancada ou planta piloto

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-13T18:29:35Z No. of bitstreams: 1 2016 - Jos? Messias Ribeiro J?nior.pdf: 2014751 bytes, checksum: f6fdac1f2a0f681e038143bedfe908ed (MD5) / Made available in DSpace on 2017-02-13T18:29:35Z (GMT). No. of bitstreams: 1 2016 - Jos? Messias Ribeiro J?nior.pdf: 2014751 bytes, checksum: f6fdac1f2a0f681e038143bedfe908ed (MD5) Previous issue date: 2016-08-30 / CENPES / Petrobras / This work has aimed to evaluate the predictive ability of simplified mathematical models to describe the dynamics of the thickening of solids in drilling fluids. In the early stages, settling experiments of barite and calcite in water-based fluids at graduated cylinders were done at initial volumetric concentrations of 6.7%, 12% and 20%, while the change of interface height was measured on the time steps. The first data modelling approach has used conservation laws, considering the relative velocity between the solid and the liquid phase as function of volumetric concentration of solids. This way, the conservation laws used to simulate these systems were based in mass conservation law and in the flux density functions. For the accuracy evaluation in the numerical data provided by conservation laws, this work has used the interface height variation through a period of time, which was determined by experiments as an auxiliary variable, to imply the prediction quality provided by the proposed model, because there was not any equipment available to determine the spatial profiles of solids concentration. Through this procedure, it was found that conservation laws was capable of predict the interface variation through a period of time with relative errors below 10%, except in regions of rapid increase of local concentration. In the second approach of modelling was used a simplified model consisting of the continuity equation and the momentum equation, considering the interaction forces between the solid and liquid phases. The simplified model describe the variation of the interface height through a period of time in several sedimentations, and the displayed results were quite satisfactory and with relative errors lower than the results showed by the conservation laws. In the final stage of this work, the simplified model was used in the simulation of time and spatial concentration profile of the barite suspended in the BR-Mul fluid, which is a real drilling fluid often used by Petrobras. The concentration profiles obtained by simulation were compared with the experimental data reported by authors from Faculty of Chemical Engineering in Federal University of Uberlandia (FEQ/UFU). In this case study, it was possible to directly compare the model output with the experimental data, and the results has showed that the relative error of the model was lower to the fluid with the highest concentration suspensions of barite, specially in the points near to the compacted zone. However, the experimental methodology used in FEQ/UFU has exhibit much imprecision in the regions of high solids concentration, because of the experimental error in the gamma ray emitter. / O presente trabalho teve como objetivo avaliar a capacidade de predi??o de modelos matem?ticos simplificados para descrever a din?mica de sedimenta??o de s?lidos adensantes em fluidos de perfura??o. Na etapa inicial deste trabalho, foram realizados experimentos de sedimenta??o de suspens?es aquosas de barita e de calcita em colunas de vidro, com concentra??es volum?tricas iniciais de 6; 7%, 12% e 20% para cada s?lido, e a varia??o da altura da interface entre a zona de clarificado e a zona de concentra??o constante foi registrada ao longo do tempo. A primeira abordagem fez uso de modelos conservativos, cuja velocidade relativa entre o s?lido e o fluido ? somente fun??o da concentra??o volum?trica local do s?lido. Dessa forma, os modelos conservativos utilizados para simular esses sistemas foram baseados nas leis de conserva??o da massa e em fun??es de densidade de fluxo. Para avaliar a acur?cia dos resultados fornecidos pelos modelos conservativos, utilizou-se a varia??o da altura da interface de clarifica??o ao longo do tempo, como vari?vel auxiliar para inferir a qualidade das predi??es fornecidas pelo modelo, visto que n?o se dispunha de equipamentos para determinar os perfis espaciais de concentra??o de s?lidos. Atrav?s deste procedimento, verificou-se que os modelos conservativos foram capazes de predizer a varia??o temporal da interface de clarifica??o com erro relativo menor que 10% na maior parte do tempo, exceto na regi?o que a concentra??o local aumenta rapidamente. Na segunda abordagem utilizou-se um modelo simplificado, composto pela equa??o da continuidade e pela equa??o do movimento, considerando as for?as de intera??o entre as fases s?lido e l?quido. O modelo simplificado descreve a varia??o temporal da interface de clarifica??o dos sistemas de sedimenta??o simples, com valores bastante satisfat?rios e com erro relativo menor do que os resultados exibidos pelos modelos conservativos. Na etapa final deste trabalho, este mesmo modelo foi avaliado na simula??o dos perfis temporais e espaciais da concentra??o de barita na sedimenta??o no fluido BR-Mul, que ? um fluido real de perfura??o bastante utilizado pela Petrobras. Os perfis de concentra??o obtidos por simula??o foram comparados a dados experimentais obtidos na Faculdade de Engenharia Qu?mica da Universidade Federal de Uberl?ndia (FEQ/UFU). Neste estudo de caso, foi poss?vel comparar diretamente a sa?da do modelo aos dados experimentais, e os resultados mostraram que o erro relativo do modelo foi menor para o fluido com a maior concentra??o inicial de barita, sobretudo nos pontos que se encontram pr?ximos da regi?o de compacta??o. No entanto, a metodologia experimental utilizada na FEQ/UFU apresenta elevada imprecis?o em regi?es com alta concentra??o de s?lidos, devido ao erro experimental introduzido na utiliza??o do equipamento emissor de raios gama.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-09-12T19:05:23Z No. of bitstreams: 1 2017 - Amanda de Paula Alves.pdf: 2949048 bytes, checksum: 68f405efb8be6119401dfd85e1d5768a (MD5) / Made available in DSpace on 2017-09-12T19:05:23Z (GMT). No. of bitstreams: 1 2017 - Amanda de Paula Alves.pdf: 2949048 bytes, checksum: 68f405efb8be6119401dfd85e1d5768a (MD5) Previous issue date: 2017-02-23 / The large amount of glycerol, produced in the last decades, generated as a by product of biodiesel production is object of inumerous studies searching for different technologies for its purification. Crude glycerol obtained as a by-product in the transesterification process is composed of alcohol, water, inorganic salts, free fatty acids, mono-, di-, triglycerides, among other organic materials and wastes in different concentrations. It is of extreme importance the purification of glycerol in order to reduce environmental problems due to its accumulation. There are current effective technologies in purifying and refining crude glycerol. However, they are considered unfeasible for small and medium production units due to the high cost and high energy demand. In this way, it is essential that new purification routes of low cost and high efficiency, as well as new markets, be developed. The adsorption process is promising and very favorable technique to remove the contaminants from glycerin due to its low cost, simplicity of design and operation. In this point of view, the objective of this work was to select an adsorbent for the purification of crude glycerol obtained from the transesterification reaction of residual oil. The evaluation of the efficiency and the best operacional conditions were studied using three types of adsorbents: Pure-Flo Supreme B81 clarifying clay, activated charcoal and diatomaceous earth. Preliminary adsorption experiments were carried out using a synthetic solution of glycerin and soybean oil, in order to verify the influence of glycerin concentration in the solution, as well as the behavior of the glycerol contaminants in the adsorption process. In order to reach the objective, the influence and optimization of the process variables as temperature (298.15, 305.65 and 313.15 K), amount of adsorbent (1.2, 1.8 and 2.4 g) and glycerol concentration (30, 50 and 70% v/v) were evaluated through an experimental design. The most significant variable was glycerol concentration, and results indicated high glycerol content after purification: 97.25% for diatomaceous earth, 95.59% for activated carbon and 90.26% for clay. Through the optimization of these variables, experiments were carried out to study the thermodynamics and kinetics of the reaction. The equilibrium time was less than 60 minutes for the three adsorbents. The negative values of Gibbs free energy (?G) showed that the adsorption of the contaminants is a spontaneous process. The negative values for enthalpy change (?H) and positive entropy (?S) values for clay and activated carbon indicate an exothermic nature and that the contaminant molecules are more randomnless in the adsorbed state than in solution. The positive value of ?H for diatomaceus earth indicates that the adsorption process for this adsorbent is endothermic. The adsorption results obtained at 298.15, 305.65 and 313.15 K showed that the experimental data were well correlated with the Langmuir, Freundlich and Redlich-Peterson isotherms models. The purification of crude glycerol using the same adsorbents did not show an effective result. The results showed that the adsorbents were not able to adsorb the impurities, but rather a small amount of glycerol. The adsorption carried out for purification did not clarify the glycerin, concluding that only the adsorption process is not suitable for purification of the crude glycerol, and a pre-purification step is necessary for the previous removal of the contaminants. / O excedente de glicerol produzido nas ?ltimas d?cadas, gerado como subproduto da produ??o de biodiesel, est? associado a constantes pesquisas por fontes alternativas de energia e vem criando uma demanda na busca de diferentes tecnologias para sua purifica??o. A glicerina bruta obtida como subproduto no processo de transesterifica??o ? composta por ?lcool, ?gua, sais inorg?nicos, ?cidos graxos livres, mono-, di-, triglicer?deos, entre outras mat?rias org?nicas e res?duos em diferentes quantidades. ? de extrema import?ncia a purifica??o do glicerol, a fim de reduzir problemas ambientais devido ao seu ac?mulo. Existem tecnologias atuais eficazes na purifica??o e refino do glicerol bruto. Por?m, s?o consideradas invi?veis para pequenas e m?dias produ??es, devido ?s restri??es de custos e alta demanda energ?tica. Dessa forma, ? indispens?vel que novas rotas de purifica??o de menor custo e maior efici?ncia, assim como novos mercados, sejam desenvolvidos. A adsor??o desponta como uma t?cnica promissora e muito favor?vel para a remo??o dos contaminantes da glicerina, devido ao seu baixo custo, simplicidade de projeto e opera??o. Diante do exposto, o objetivo deste trabalho foi selecionar um adsorvente para a purifica??o do glicerol bruto obtido da rea??o de transesterifica??o de ?leo residual. Para a avalia??o da efici?ncia e escolha das melhores condi??es de purifica??o, foram avaliados tr?s tipos de adsorventes: argila clarificante Pure-Flo Supreme B81, carv?o ativado e terra diatom?cea. Experimentos de adsor??o foram realizados utilizando uma solu??o sint?tica de glicerina P.A. e ?leo de soja, com o intuito de verificar a influ?ncia da concentra??o da glicerina na solu??o, assim como o comportamento dos contaminantes do glicerol no processo de adsor??o. Para atingir o objetivo, avaliou-se a influ?ncia e otimiza??o das vari?veis de processo como temperatura (298,15, 305,65 e 313,15 K), quantidade de adsorvente (1,2, 1,8 e 2,4 g) e concentra??o de glicerol (30, 50 e 70% v/v) atrav?s de um planejamento experimental. A vari?vel mais significativa foi a concentra??o de glicerol, e resultados indicaram alto teor de glicerol ap?s a purifica??o: 97,25% para terra diatom?cea, 95,59% para carv?o e 90,26% para argila. Al?m disso, foram realizados experimentos para o estudo da termodin?mica e cin?tica da rea??o e o tempo necess?rio para o sistema alcan?ar o equil?brio foi inferior a 60 minutos para os tr?s adsorventes. Os valores negativos da varia??o da energia livre de Gibbs (?G) mostraram que a adsor??o dos contaminantes ? um processo espont?neo. Os valores negativos para varia??o de entalpia (?H) e os valores positivos de entropia (?S) para argila e carv?o ativado, indicam uma natureza exot?rmica e que as mol?culas dos contaminantes encontram-se mais desordenadas no estado adsorvido do que em solu??o. O valor positivo de ?H para a terra diatom?cea indica que o processo de adsor??o para esse adsorvente ? endot?rmico. As an?lises dos resultados de adsor??o obtidos nas temperaturas de 298,15, 305,65 e 313,15 K, mostraram que os dados experimentais foram bem correlacionados ?s isotermas de Langmuir, Freundlich e Redlich Peterson. Utilizando as mesmas vari?veis para o processo de adsor??o usando o glicerol bruto, os resultados mostraram que os adsorventes n?o foram capazes de adsorver as impurezas, mas sim glicerol. A adsor??o realizada para purifica??o n?o clarificou a glicerina, indicando que n?o houve remo??o das impurezas, concluindo que somente o processo de adsor??o n?o ? apropriado para purifica??o do glicerol bruto, sendo necess?rio uma pr?-purifica??o para pr?via remo??o de alguns contaminantes.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-12T17:56:54Z No. of bitstreams: 1 2013 - N?bya Dalvi Calabrez.pdf: 2204521 bytes, checksum: 71b05e242a3884d827606854f30c0359 (MD5) / Made available in DSpace on 2018-11-12T17:56:54Z (GMT). No. of bitstreams: 1 2013 - N?bya Dalvi Calabrez.pdf: 2204521 bytes, checksum: 71b05e242a3884d827606854f30c0359 (MD5) Previous issue date: 2013-08-23 / CAPES / Petrobras / Filtration and invasion of drilling fluids are phenomena that occur during the process of drilling oil wells. It is necessary to know the filter cake behavior, which is formed in order to prevent unwanted invasion of filtrate, which can cause irreversible damage for the reservoir rock, making impossible the well to produce oil. The goals of this work were: to study filtration and invasion of drilling fluids, under static and dynamic conditions, characterize the mudcake, obtain comparative results between different fluids (water base mud and emulsion) and model static filtration. For this, experiments were conducted in a high temperature/high pressure cell filtration, using filter paper as filter medium. The cake formed from the filtration of these fluids was characterized according to parameters such as porosity, permeability, compressibility, thickness, shear strength and friction factor. In a comparison between different fluids, it was observed that the water-based mud provided a mudcake more permeable and more porous than emulsion mudcake. Thus, water-based mud allowed more filtrate passed through the filter medium. The factors relevant to the estimation of the friction factor were determined. It was concluded that the compressibility index of the filter cake was a factor which had great influence on the estimation of this parameter. The model allowed the prediction of static filtration, slowness and mudcake thickness curves as a function of time. / A filtra??o e a invas?o de fluidos de perfura??o s?o fen?menos que ocorrem durante o processo de perfura??o de po?os de petr?leo. ? necess?rio conhecer como se comporta a torta de filtra??o formada a fim de evitar invas?es indesejadas do filtrado, o que pode causar danos muitas vezes irrevers?veis a rocha reservat?rio, tornando o po?o invi?vel para a produ??o do ?leo. Os objetivos desse trabalho foram: estudar os fen?menos de filtra??o e invas?o de fluidos de perfura??o base ?gua e emuls?o, sob condi??es est?ticas e din?micas, caracterizar a torta formada, obter resultados comparativos entre diferentes fluidos (base ?gua e emuls?o) e modelar a filtra??o est?tica. Para isso, foram conduzidos experimentos em uma c?lula de filtra??o high temperature/high presssure, utilizando papel de filtro como meio filtrante. A torta formada, a partir da filtra??o desses fluidos, foi caracterizada de acordo com par?metros como: porosidade, permeabilidade, compressibilidade, espessura, resist?ncia ao cisalhamento e fator de fric??o. Na compara??o entre os resultados experimentais para diferentes fluidos, observou-se que o fluido a base ?gua, por formar uma torta mais perme?vel e mais porosa, permitiu que mais filtrado passasse pelo meio filtrante, quando comparado ao fluido base ?leo (emuls?o). Foram estudados os fatores relevantes na estima??o do fator de fric??o da torta de filtra??o e concluiu-se que a compressibilidade da torta foi um fator que teve grande influ?ncia na estima??o desse par?metro. A modelagem da filtra??o est?tica possibilitou a previs?o do comportamento das curvas de filtra??o, de slowness e da espessura da torta em fun??o do tempo.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-21T16:44:58Z No. of bitstreams: 1 2013 - Beatriz Autullo Ramos.pdf: 1610426 bytes, checksum: c3defc33414fda5b010152756fc0f0ce (MD5) / Made available in DSpace on 2018-11-21T16:45:00Z (GMT). No. of bitstreams: 1 2013 - Beatriz Autullo Ramos.pdf: 1610426 bytes, checksum: c3defc33414fda5b010152756fc0f0ce (MD5) Previous issue date: 2013-08-29 / CAPES / FAPERJ / The aim of this study was to obtain the sorption isotherms, analyze the kinetics of drying jatropha seeds, perform mathematical modeling of sorption isotherms and kinetic experiments, and to study the thermodynamics of the process. Seeds with initial moisture content of 8-10%, dry basis, were used. The sorption isotherms were found using two experimental devices: a water activity meter and a thermal bath with temperatures adjusted at 30, 40 and 50 ?C for the first apparatus and 40, 50 and 60 ?C for the second one. To obtain the sorption isotherms with a thermal bath the method of saturated saline solutions of MgCl2, K2CO3, KI, NaCl, and NaBrO3 was applied and the time to reach equilibrium was, generally, 20 days. Nine kinetic experiments were performed setting temperatures at 30, 40 and 50 ?C, and the superficial gas velocity at 397, 794 and 1190 cm/min, with duration of three hundred and sixty minutes. Oswin's mathematical model was the best to describe the hygroscopic behavior of the isotherms found with the water activity meter, while Caurie's model was the best for the thermal bath data, because they showed the lowest deviations and the highest coefficients of determination. ANOVA indicated that only the water activity has significant influence over the equilibrium moisture on the sorption isotherm experiments, in both equipments. Nine mathematical models were tested to simulate the kinetics and the ?two exponential terms? model presented the lowest deviations and highest coefficients of determination. It was observed that the temperature and superficial gas velocity did not significantly influence the kinetic experiments. For calculation of the thermodynamic properties the models that best fitted the data of the two experiments to obtain the sorption isotherms were used. The positive values of the differential enthalpy and entropy for both studies showed that the sorption process of jatropha seeds is endothermic and irreversible. The negative values of the Gibbs free energy variation for both studies indicated that the sorption process occurs spontaneously for the temperature conditions evaluated. The enthalpy-entropy compensation theory was applied satisfactorily and Krug?s test showed that the isokinetic temperature was different from the harmonic mean temperature in both studies. / O objetivo deste trabalho foi obter as isotermas de sor??o, analisar a cin?tica de secagem da semente do pinh?o-manso, realizar a modelagem matem?tica dos experimentos da isoterma de equil?brio e de cin?tica, e o estudo termodin?mico do processo. Utilizaram-se sementes com teor de umidade inicial de 8 a 10 %, em base seca. Os experimentos de determina??o da isoterma de equil?brio foram realizados utilizando dois equipamentos: o medidor de atividade de ?gua e o banho t?rmico, com faixas de temperatura de 30, 40 e 50 ?C, para o primeiro, e de 40, 50 e 60 ?C, para o segundo. As isotermas obtidas pelo banho t?rmico foram obtidas atrav?s do m?todo das solu??es salinas saturadas de MgCl2, K2CO3, KI, NaCl e NaBrO3 e o tempo para atingir o equil?brio foi, em geral, de 20 dias. Foram realizados nove experimentos de cin?tica, nas temperaturas de 30, 40 e 50 ?C, com velocidade superficial do g?s de 397, 794 e 1190 cm/min, com dura??o de trezentos e sessenta minutos. O melhor modelo matem?tico selecionado para descrever o comportamento higrosc?pico das isotermas foi o Oswin, para o medidor de atividade de ?gua, e o de Caurie, para o banho t?rmico, pois apresentaram os menores desvios e os maiores coeficientes de determina??o. Atrav?s da ANOVA verificou-se que somente a atividade de ?gua apresentou influencia significativa sobre a umidade de equil?brio para os experimentos de isoterma, em ambos os equipamentos. Nove modelos matem?ticos foram testados para a simula??o da cin?tica sendo que o modelo de ?Dois termos exponenciais? apresentou os menores desvios e os maiores coeficientes de determina??o. Observou-se que a temperatura e a velocidade superficial do g?s n?o influenciaram significativamente os experimentos de cin?tica. Para os c?lculos das propriedades termodin?micas foram utilizados os modelos que melhor ajustaram os dados dos dois experimentos para obten??o das isotermas de sor??o. Os valores positivos de entalpia e entropia diferencial, para ambos os estudos, mostraram que o processo de sor??o de ?gua nos gr?os de pinh?o-manso ? endot?rmico e irrevers?vel. Os valores negativos da varia??o da energia livre de Gibbs, para os dois estudos, indicaram que o processo de sor??o ocorre de forma espont?nea para as condi??es de temperatura avaliadas. A teoria compensat?ria entalpia-entropia foi aplicada de forma satisfat?ria, e o teste de Krug mostrou que a temperatura isocin?tica foi diferente da temperatura m?dia harm?nica nos dois estudos realizados.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-21T17:20:01Z No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) / Made available in DSpace on 2017-06-21T17:20:01Z (GMT). No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) Previous issue date: 2015-07-22 / The need of producing polymeric artifacts increasingly powerful and versatile but which have increasingly lower biodegradation times motivates the scientific community to seek combinations of natural and synthetic polymers in order to meet both aspects. The manufacture of the blend LDPE/TPS Starch / Chitosan aims to go against that objective. The biodegradation occurs mostly in the soil. Trying to understand the dynamics of the biodegradation process in soil, this paper monitored the effects caused by deposition of the blend, analyzing different parameters, such as organic carbon, organic matter and microbial carbon, indicating levels of soil quality.The blends were prepared with different concentrations of chitosan, with values set to 0, 7, 5 and 15% of total mass and buried in pure soil and soil treated with humus. The analysis periods were 10, 40, 70, 100 and 130 days, with samples being exposed to the environment. Infrared analysis were performed using Fourier transform, X-ray diffraction, scanning electron microscopy with spectroscopy dispersive energy before and after biodegradation mass loss, after the biodegradation process of the blends. Organic carbon, organic matter, microbial carbon, pH and moisture in the soil.The results obtained after analysis in blend showed that with the passage of time, the biodegradation process happened, considering that carbon levels dropped considerably and oxygen were increased in accordance with the EDS analysis. The FTIR analysis confirmed this fact by showing that there was an intese oxidative process, especially in the initial 70 days in all samples. The X-RD analysis showed that there was a variationin crystallinity, but always with a decrease of this paramenter. The weight loss was also significant and progressive in all samples. Soil results showed that the same is resilient and can recover its characteristics during the biodegradation process. At the beginning of the experiment, especially in the first 40 ays, all evaluated paramenters declined considerably, but returned to baseline levels and maintained these values by the end of the experiment. Experimental design was made and it showed that none of the dependent variables influenced the biodegradion process. / A necessidade de produzir artefatos polim?ricos cada vez mais vers?teis e ?performantes? e que apresentem caracter?sticas de biodegrada??o cada vez mais acentuadas tem motivado a comunidade cient?fica a buscar combina??es entre pol?meros sint?ticos e naturais com o objetivo de atender esses aspectos. O desenvolvimento de blendas de polietileno de baixa densidade/amido termopl?stico/quitosana (PEBD/TPS/Q) e de amido termopl?stico/quitosana (TPS/Q) visou ir de encontro a tal objetivo, procurando entender a din?mica do processo biodegradativo no solo. O presente trabalho acompanhou os efeitos causados pela deposi??o dessas blendas, analisando diferentes par?metros, como carbono org?nico total, massa org?nica total e carbono de biomassa microbiana, que indicam n?veis de qualidade do solo, al?m da perda de massa ap?s cada per?odo de biodegrada??o. As blendas de PEBD/TPS/Q e TPS/Q foram preparadas com diferentes concentra??es de quitosana, com valores definidos em 0, 7,5 e 15% da massa total e enterradas em solo puro e solo tratado com h?mus. Os per?odos de an?lise de biodegrada??o foram de 10, 40, 70, 100 e 130 dias, com as amostras sendo expostas ao ambiente. As blendas foram analisadas por espectroscopia de infravermelho com transformada de Fourier (FTIR), difra??o de raios-X (DRX), microscopia eletr?nica de varredura com espectroscopia de energia dispersiva (MEV/EDS), e quanto a perda de massa, antes e ap?s o processo de biodegrada??o. Tamb?m foram realizadas an?lises de carbono org?nico total, massa org?nica total, concentra??o de carbono de biomassa microbiana, pH e umidade dos solos utilizados. Os resultados comprovaram o processo biodegradativo das blendas com o passar do tempo, tendo em vista a diminui??o dos n?veis de carbono e aumento consider?vel dos n?veis de oxig?nio das blendas de PEBD/TPS/Q, de acordo com as an?lises de FTIR e EDS, e total biodegrada??o das blendas de TPS/Q. As bandas de FTIR comprovaram a ocorr?ncia do processo oxidativo, principalmente nos 70 dias iniciais, nas amostras de PEBD/TPS/Q. As an?lises de DRX mostraram que houve uma varia??o da cristalinidade, com a tend?ncia de diminui??o deste par?metro. A perda de massa tamb?m foi consider?vel e progressiva para todas as amostras. Os resultados de an?lise das amostras de solo mostraram o poder de recupera??o da atividade microbiana dos mesmos (resili?ncia) durante o processo biodegradativo. No per?odo inicial do experimento, em especial nos primeiros 40 dias, todos os par?metros avaliados sofreram decaimento de seus valores, por?m retornaram aos patamares iniciais e mantiveram esses valores at? o final do experimento. O planejamento experimental realizado mostrou que nenhuma das vari?veis independentes influenciou no processo de bioatividade do solo.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-07-25T14:24:04Z No. of bitstreams: 1 2009 - Eduardo Rangel Braga.pdf: 1956266 bytes, checksum: ae6382d24285821071b6ba5bbba30198 (MD5) / Made available in DSpace on 2017-07-25T14:24:05Z (GMT). No. of bitstreams: 1 2009 - Eduardo Rangel Braga.pdf: 1956266 bytes, checksum: ae6382d24285821071b6ba5bbba30198 (MD5) Previous issue date: 2009-09-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES, Brasil. / The need for technological advances in the operation of drilling wells for oil has encouraged the research and development of drilling fluids, like the study of the its flowing in different geometries. On this work is studied the flow of two drilling fluids in pipe and annular tube with the objective to evaluate rheological models that describe the fluid behavior, to characterize the flow regimes using the experimental method and compare with correlations found in literature, to evaluate equations of hydraulic diameter found in the literature, to evaluate correlations of friction factor in the turbulent regime and to propose new correlations for the friction factor in turbulent regime. The data are obtained in a pilot plant consisting of a system operating in closed circuit of 6 meters composed of horizontal tubes made of galvanized iron, arranged in three parallel lines of independent flows that allow the measurement of friction loss caused by a circular tube of 1" of diameter and by two ratios of concentric annular tubes (annulus formed by 2" and 3/4 "and 1 1/4" and 1/2"). The system consists of a tank with a capacity of 500 liters, with a mechanical stirrer, connected to a positive displacement pump of helical type with 25HP, operating with volumetric flow up to 20m3/h. The pilot plant is instrumented with a set of three transducers of pressure. The rheology of the fluid is evaluated with the aid of a FANN viscometer, model 35A. The rheological models used are the power law and Casson. The results show that the choice of equations of hydraulic diameter and friction factor are dependent on the geometry of flow and the rheological model used, showing that should be analyzed separately. The new correlations of friction factor for turbulent regime generate good results. / A necessidade de avan?os tecnol?gicos na opera??o de perfura??o de po?os de petr?leo tem incentivado a pesquisa e o desenvolvimento de fluidos de perfura??o, assim como o estudo do escoamento dos mesmos em geometrias distintas. Neste trabalho ? estudado o escoamento de dois fluidos de perfura??o em tubos e dutos anulares, com o objetivo de avaliar modelos reol?gicos que descrevam o comportamento do fluido, caracterizar os regimes de escoamento utilizando m?todo experimental e comparar com correla??es encontradas na literatura, avaliar equa??es de di?metro hidr?ulico encontradas na literatura, avaliar correla??es de fator de atrito no regime turbulento e propor novas correla??es para o fator de atrito no regime turbulento. Os dados s?o obtidos em uma unidade piloto constitu?da de um sistema operando em circuito fechado de 6 metros de extens?o horizontal composto de tubos de ferro galvanizado, dispostos em tr?s linhas paralelas de escoamento independentes que permitem a avalia??o da perda de carga ocasionada em um tubo circular de 1" de di?metro e em duas raz?es de anulares conc?ntricos (?nulo formado pelos tubos de 2" e 3/4", e 1 1/4" e ?"). O sistema ? composto de um tanque com capacidade de 500 litros, dotado de um agitador mec?nico, conectado a uma bomba de deslocamento positivo do tipo helicoidal de 25HP, operando com vaz?es de at? 20m3/h. A unidade piloto ? instrumentada com um conjunto de tr?s transdutores de press?o. A reologia do fluido ? avaliada com o aux?lio de um viscos?metro FANN, modelo 35A. Os modelos reol?gicos adotados s?o o da pot?ncia e Casson. Os resultados revelam que a escolha das equa??es de di?metro hidr?ulico e fator de atrito s?o dependentes da geometria do escoamento e do modelo reol?gico utilizado, devendo ser analisados separadamente. As novas correla??es de fator de atrito para o regime turbulento geram bons resultados.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-04T18:29:32Z No. of bitstreams: 1 2017 - Roberta Benic? Sartori.pdf: 2251565 bytes, checksum: 2cc548260ea3d0f5856e36bbb514bf7f (MD5) / Made available in DSpace on 2017-08-04T18:29:32Z (GMT). No. of bitstreams: 1 2017 - Roberta Benic? Sartori.pdf: 2251565 bytes, checksum: 2cc548260ea3d0f5856e36bbb514bf7f (MD5) Previous issue date: 2017-02-22 / Banana is a tropical fruit cultivated in warm places and harvested during the whole year, as well as its consumption is intense. It is known that banana productivity, however, is threatened due to the vulnerability of the cultivars to some pests and diseases. Because of this, some agrochemicals are recommended to avoid the attack of these hindrances such as: azoxystrobin, chlorothalonil, diphenoconazole, imazalil, bifenthrin, and chlorpyriphos. All of them can cause serious health problems in humans such as cancer and neurological diseases and adverse reproductive effects are associated with the consumption and/or exposure to these hazardous substances. However, even when applied in conformity with Good Agricultural Practices, pesticides can leave residues, that can still be present in the soils as well as in the fruits. Due to these considerations, this study has as aim the technical evaluation of supercritical fluid in the extraction of pesticides present in banana flour (Musa spp). Therefore, the whole fruits (8 g), previously submitted to lyophilization and milling were fortified, during a stable period of overnight, with a solution containing the agrochemical standards mentioned above, diluted in methanol. The experimental unit consisted basically of a 42 mL extractor, a high pressure pump and a micrometering valve to sample removal. Different operational conditions were investigated (60 ?C ? 200 bar; 46 ?C ? 244 bar; 74 ?C ? 244 bar; 40 ?C ? 350 bar; 60 ?C ? 350 bar; 80 ?C ? 350 bar; 46 ?C ? 456 bar; 74 ?C ? 456 bar and 60 ?C ? 500 bar) based on an experimental design. The analysis of the extracted pesticides was performed using an ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS). It was observed that the yield of the extract increased with the temperature increasing. According to the results, the extraction at 80 ?C and 350 bar was able to remove 1.4194% of the extracts in the banana. The yield of pesticides increased with the pressure increasing and the better condition was at 500 bar and 60 ?C. The experimental data were well modelled by the models of Esqu?vel et al. (1999), Reverchon & Osseo (1994), Zekovi? et al. (2003) and Sovov? (1999). The Chrastil (1982) model could represent the solubility behavior of the pesticides with the variation of temperature and pressure. / A banana ? uma fruta tropical cultivada em locais quentes e colhida durante todo o ano, assim como seu consumo ? intenso durante todo o ano. Sabe-se que a produtividade da banana, no entanto, est? amea?ada devido ? vulnerabilidade de tais cultivares a algumas pragas e doen?as. Devido a isso, alguns agroqu?micos s?o recomendados para evitar o ataque destes entraves ? produtividade da banana, tais como: azoxistrobina, clorotalonil, difenoconazol, imazalil, bifentrina e clorpirifos. Todos esses compostos podem causar s?rios problemas de sa?de em seres humanos, como o c?ncer, assim como doen?as neurol?gicas e efeitos reprodutivos adversos est?o associados ? ingest?o e/ou exposi??o a estas subst?ncias perigosas. No entanto, mesmo quando aplicados em conformidade com as Boas Pr?ticas Agr?colas, os pesticidas podem deixar res?duos, que ainda podem estar presentes tanto nos solos como nos frutos. Devido a estas considera??es, este estudo tem como objetivo a avalia??o t?cnica do fluido supercr?tico na extra??o de agrot?xicos presentes na farinha de banana (Musa spp). Assim, os frutos inteiros (8 g), previamente submetidos ? liofiliza??o e moagem foram fortificados, durante um per?odo est?vel de um dia para o outro, com uma solu??o contendo os padr?es dos pesticidas mencionados acima, dilu?dos em metanol. A unidade experimental consiste basicamente em um extrator de 42 mL, uma bomba de alta press?o e uma v?lvula microm?trica para remo??o da amostra. Foram investigadas diferentes condi??es operacionais (60 ?C a 200 bar, 46 ?C a 244 bar, 74 ?C a 244 bar, 40 ?C a 350 bar, 60 ?C a 350 bar, 80 ?C a 350 bar, 46 ?C a 456 bar e 74 ?C - 456 bar e 60 ?C - 500 bar) com base em um planejamento experimental. A an?lise dos pesticidas extra?dos foi realizada utilizando cromatografia l?quida de ultra desempenho acoplada ao espectr?metro de massa (UPLC-MS). Observou-se que o rendimento do extrato aumentou com o aumento da temperatura. De acordo com os resultados, a extra??o a 80 ?C e 350 bar foi capaz de remover 1,4194% dos extratos na banana. Para o rendimento de pesticidas, observou-se um aumento com o aumento da press?o e a melhor condi??o foi a 500 bar e 60 ?C. Os dados experimentais foram modelados pelos modelos de Esqu?vel et al. (1999), Reverchon & Osseo (1994), Zekovi? et al. (2003) e Sovov? (1999), apresentando boa correla??o. O modelo de Chrastil (1982) conseguiu representar o comportamento da solubilidade dos agrot?xicos com a varia??o de temperatura e press?o.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-09T20:05:40Z No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) / Made available in DSpace on 2017-05-09T20:05:40Z (GMT). No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Previous issue date: 2016-12-12 / CAPES / Natural gas is extensively used in industries as well as in other sectors as an energy resource and, sometimes, it needs to undergo processes for the removal of impurities present in its composition. Among them are the sulfur compounds, which can cause damages to pipes and catalysts, making it necessary to develop and/or improve deep desulfurization methods. In this context, granular activated carbon was modified through two methods, oxidation using nitric acid, and impregnation using a ferric chloride solution. The resulting adsorbents were evaluated for their capacity of adsorbing seven sulfur compounds present in the synthetic natural gas sample, through their rupture curves. Afterwards, the adsorbents desorption was performed by using supercritical carbon dioxide under the conditions of 60?C at 100 bar, 150 bar and 200 bar. The results indicate that all the modification methods improved the sulfur compounds retention when compared to virgin activated carbon. The compound that had the greatest increase in the adsorption capacity after iron impregnation was the tert-butyl mercaptan (TBM), and with the activated carbon oxidized by HNO3 it was the dimethyl sulfide (DMS). Nevertheless, the supercritical conditions studied in the desorption stage were efficient only for the unmodified activated carbon. The adsorption capacities of both modified adsorbents after the regeneration were inferior to those capacities obtained in the first adsorption, then two hypotheses were investigated: (1) destruction of the newly created sites after regeneration; and (2) incomplete desorption in the studied supercritical conditions. Through other experiments it was proved that, after regeneration, there was no destruction of the newly created sites; therefore, further studies on the operating conditions are required in order to the modified adsorbents to achieve high regeneration capacities. / O g?s natural ? utilizado nas ind?strias e em outros setores como fonte de energia e necessita, por vezes, de processos de remo??o das impurezas presentes em sua composi??o. Dentre elas est?o os compostos de enxofre, que provocam danos em tubula??es e catalisadores, sendo necess?rio o desenvolvimento e/ou o aperfei?oamento de m?todos para a dessulfuriza??o profunda. Nesse contexto, um carv?o ativado granular foi modificado por meio de dois m?todos, oxida??o utilizando ?cido n?trico e por impregna??o usando uma solu??o de cloreto de ferro III, os adsorventes resultantes foram avaliados quanto ? sua capacidade para adsorver sete compostos de enxofre presentes em uma amostra de g?s natural sint?tica, atrav?s das curvas de rupturas. Posteriormente, foi realizada a dessor??o dos adsorventes utilizando di?xido de carbono supercr?tico nas condi??es de 60 ?C a 100 bar, 150 bar e 200 bar. Os resultados indicam que todos os m?todos de modifica??o melhoraram a reten??o dos compostos sulfurados individuais em compara??o com o carv?o ativado virgem. O composto que obteve maior aumento da capacidade de adsor??o ap?s a impregna??o com ferro foi o terc-butilmercaptana (TBM), e com o carv?o ativado oxidado pelo HNO3 foi o metiletilsulfeto (DMS). J? as condi??es supercr?ticas estudadas na etapa de dessor??o foram eficientes somente para o carv?o ativado n?o modificado. As capacidades de adsor??o dos dois adsorventes modificados ap?s a regenera??o foram inferiores aos obtidos na primeira adsor??o, ent?o duas hip?teses foram investigadas: (1) destrui??o dos novos s?tios criados ap?s a regenera??o; e (2) dessor??o incompleta nas condi??es supercr?ticas estudadas. Atrav?s de outros experimentos comprovou-se que n?o houve ? destrui??o dos novos s?tios criados ap?s a regenera??o, sendo necess?rio um estudo mais profundo em rela??o ?s condi??es operacionais, a fim de alcan?ar altas capacidades de regenera??o dos adsorventes modificados.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-05-10T18:21:02Z No. of bitstreams: 1 2017 - Bianca Rangel Antunes da Silva.pdf: 2187606 bytes, checksum: 927fe528eb48db49953e8f982d4320d5 (MD5) / Made available in DSpace on 2018-05-10T18:21:02Z (GMT). No. of bitstreams: 1 2017 - Bianca Rangel Antunes da Silva.pdf: 2187606 bytes, checksum: 927fe528eb48db49953e8f982d4320d5 (MD5) Previous issue date: 2017-12-21 / During the drilling of oil wells, the pressure differential between the rock formation and the annular region can cause a filtration process and consequent invasion of drilling fluid into the rocks, causing irreversible damage to the well. Therefore, studies to control the properties of the well formed mudcake are fundamental. The mudcake formed should be thin and of low permeability, thus minimizing the filtration and the invasion of the fluid. The main purpose of this work was to study the characteristics of the filtration pie formed during the drilling process of oil wells, using non-Newtonian fluids that follow the Power law model, and applying the simplified theory of filtration adapted for non-Newtonian fluids to achieve the specific objective that was the lifting of the parameters of permeability, porosity, thickness and correction factor obtained from experimental data of filtered volume versus time, in Static conditions, at different pressures. Experimental results were obtained in different filtration conditions (pressure, viscosifier agent and weighting material) seeking to compare and know the mechanisms that control filtration in static conditions. Filtration tests were carried out at 300 psi, 500 psi and 700 psi, using a HTHP cell and prepared non-Newtonian drilling fluids containing xanthan gum (XG) and carboxymethylcellulose (CMC) as viscosifier agent, in addition to calcite and barite. Filtration parameters such as permeability, porosity, pie thickness, filtration time and filtered volume have been evaluated. The permeability of the pie was determined, with the aid of a software of estimation of parameters, using the simplified theory of filtration adapted for non Newtonian fluids proposed by Massarani and Coelho de Castro(1980). The results obtained were confronted with those obtained by other methodologies. The experimental tests also showed that the properties of the pie vary with the filtration pressure. / Durante o processo de perfura??o de po?os de petr?leo, o diferencial de press?o entre a forma??o rochosa e a regi?o anular pode ocasionar um processo de filtra??o e consequente invas?o de fluido de perfura??o nas rochas, causando opera??es irrevers?veis ao po?o. Por isso, s?o fundamentais estudos para controlar as propriedades da torta de filtra??o formada na parede do po?o. A torta formada deve ser fina e de baixa permeabilidade, minimizando assim a filtra??o e a invas?o do fluido. Este trabalho teve como objetivo principal estudar as caracter?sticas da torta de filtra??o formada durante o processo de perfura??o de po?os de petr?leo, utilizando fluidos n?o Newtonianos que seguem a lei da pot?ncia,e aplicando a teoria simplificada da filtra??o adaptada para fluidos n?o Newtonianos para atingir o objetivo espec?fico que foi o levantamento dos par?metros de permeabilidade, porosidade, espessura e fator de corre??o obtidos a partir de dados experimentais de volume de filtrado versus tempo, em condi??es est?ticas, em diferentes press?es.Foram obtidos resultados experimentais em diferentes condi??es de filtra??o (press?o, viscosificante e adensante) buscando comparar e conhecer os mecanismos que controlam a filtra??o em condi??es est?ticas. Foram realizados ensaios de filtra??o a 300 psi, 500 psi e 700 psi, utilizando uma c?lula HTHP e preparados fluidos de perfura??o n?o-Newtonianos contendo Goma Xantana (GX) e carboximetilcelulose (CMC) como viscosificantes, al?m de barita e calcita. Foram avaliados os par?metros da filtra??o como permeabilidade, porosidade, espessura da torta, tempo de filtra??o e volume de filtrado. A permeabilidadeda torta foideterminada, com o aux?lio de umsoftware de estima??o de par?metros, utilizando-sea teoria simplificada da filtra??o adaptada para fluidos n?o Newtonianos proposta por Massarani e Coelho de Castro (1980). Os resultados obtidos foram confrontados com os obtidos por outras metodologias. Os ensaios experimentais mostraram tamb?m que as propriedades da torta variam com a press?o de filtra??o.