Adsorção de cobre e cromo utilizando fibra de sisal visando o tratamento da água produzida pela indústria petrolífera

Currently, the oil industry is the biggest cause of environmental pollution. The objective was to reduce the concentration of copper and chromium in the water produced by the oil industry. It was used as adsorbent natural sisal fiber Agave sp treated with nitric acid and sodium hydroxide. All vegetable fibers have physical and morphological properties that enablies the adsorption of pollutants. The basic composition of sisal is cellulose, hemicellulose and lignin. The features are typically found in the characterization of vegetable fibers, except the surface area that was practically zero. In the first stage of adsorption, it was evaluated the effect of temperature and time skeeking to optimize the execution of the factorial design. The results showed that the most feasible fiber was the one treated with acid in five hours (30°C). The second phase was a factorial design, using acid and five hours, this time was it determined in the first phase. The tests were conducted following the experimental design and the results were analyzed by statistical methods in order to optimize the main parameters that influence the process: pH, concentration (mol / L) and fiber mass/ metal solution volume. The volume / mass ratio factor showed significant interference in the adsorption process of chromium and copper. The results obtained after optimization showed that the highest percentages of extraction (98%) were obtained on the following operating conditions: pH: 5-6, Concentration: 100 ppm and mass/ volume: 1 gram of fiber/50mL solution. The results showed that the adsorption process was efficient to remove chromium and copper using sisal fibers, however, requiring further studies to optimize the process.

Metodologia de utilização de dados de sensoriamento remoto em zonas costeiras sob influência da indústria petrolífera

Oil spills in marine environments represent immediate environmental impacts of large magnitude. For that reason the Environmental Sensitivity to Oil Maps constitute a major instrument for planning actions of containment and cleanup. For both the Environmental Sensitivity Maps always need to be updated, to have an appropriate scale and to represent accurately the coastal areas. In this context, this thesis presents a methodology for collecting and processing remote sensing data for the purpose of updating the territorial basis of thematic maps of Environmental Sensitivity to Oil. To ensure greater applicability of the methodology, sensors with complementary characteristics, which provide their data at a low financial cost, were selected and tested. To test the methodology, an area located on the northern coast of the Northeast of Brazil was chosen. The results showed that the products of ASTER data and image hybrid sensor PALSAR + CCD and HRC + CCD, have a great potential to be used as a source of cartographic information on projects that seek to update the Environmental Sensitivity Maps of Oil

Contribuição da Geodésia ao monitoramento costeiro do Litoral Setentrional do Rio Grande do Norte, área de influência da indústria petrolífera

The general objective of this thesis has been seasonal monitoring (quarterly time scale) of coastal and estuarine areas of a section of the Northern Coast of Rio Grande do Norte, Brazil, environmentally sensitive and with intense sediment erosion in the oil activities to underpin the implementation of projects for containment of erosion and mitigate the impacts of coastal dynamics. In order to achieve the general objective, the work was done systematically in three stages which consisted the specific objectives. The first stage was the implementation of geodetic reference infrastructure for carrying out the geodetic survey of the study area. This process included the implementation of RGLS (Northern Coast of the RN GPS Network), consisting of stations with geodetic coordinates and orthometric heights of precision; positioning of Benchmarks and evaluation of the gravimetric geoid available, for use in GPS altimetry of precision; and development of software for GPS altimetry of precision. The second stage was the development and improvement of methodologies for collection, processing, representation, integration and analysis of CoastLine (CL) and Digital Elevation Models (DEM) obtained by geodetic positioning techniques. As part of this stage have been made since, the choice of equipment and positioning methods to be used, depending on the required precision and structure implanted, and the definition of the LC indicator and of the geodesic references best suited, to coastal monitoring of precision. The third step was the seasonal geodesic monitoring of the study area. It was defined the execution times of the geodetic surveys by analyzing the pattern of sediment dynamics of the study area; the performing of surveys in order to calculate and locate areas and volumes of erosion and accretion (sandy and volumetric sedimentary balance) occurred on CL and on the beaches and islands surfaces throughout the year, and study of correlations between the measured variations (in area and volume) between each survey and the action of the coastal dynamic agents. The results allowed an integrated study of spatial and temporal interrelationships of the causes and consequences of intensive coastal processes operating in the area, especially to the measurement of variability of erosion, transport, balance and supply sedimentary over the annual cycle of construction and destruction of beaches. In the analysis of the results, it was possible to identify the causes and consequences of severe coastal erosion occurred on beaches exposed, to analyze the recovery of beaches and the accretion occurring in tidal inlets and estuaries. From the optics of seasonal variations in the CL, human interventions to erosion contention have been proposed with the aim of restoring the previous situation of the beaches in the process of erosion.

Modelagem do desempenho ambiental dos projetos de exploração e produção aplicando equações estruturais

A legislação ambiental e os principais agentes que se relacionam com a empresa se constituem em fatores exógenos que não podem ser negligenciados ao formular-se e avaliar-se a política ambiental corporativa. As influências exógenas e seus efeitos sobre a gestão ambiental e o gerenciamento de projetos de exploração e produção (E&P) e, por essa via, sobre o desempenho ambiental, foram objetos de estudo desta tese. Embora o desempenho ambiental seja um assunto relevante, a pesquisa sobre esse tema ainda é escassa. Tal carência desponta ainda mais acentuada quando se aborda o desempenho ambiental de projetos na indústria de petróleo e gás. O principal objetivo deste estudo foi avaliar a relação entre a legislação ambiental vigente, as ações de órgãos reguladores, fornecedores, empresas terceirizadas e comunidades locais e o desempenho ambiental dos projetos de E&P na indústria de petróleo e gás e, também, analisar os efeitos do sistema de gestão ambiental e o gerenciamento dos projetos sobre tal desempenho. Na fase abdutiva, foi conduzido um estudo de caso com abordagem qualitativa em uma grande empresa brasileira do setor de petróleo e gás, na fase dedutiva, foi realizada uma pesquisa survey explanatória de corte transversal com abordagem quantitativa, incluindo 113 projetos de E&P de cinco unidades executoras da empresa. Foi formulado um modelo conceitual, com cinco construtos e sete hipóteses de pesquisa, representativo dos efeitos de fatores externos sobre o desempenho ambiental dos projetos de E&P. Os dados foram tratados aplicando a Análise Fatorial Exploratória e a Modelagem de Equações Estruturais com aplicação dos softwares IBM® SPSS® Statistics 20.0 e IBM® SPSS® Amos 18.0. O modelo de equações estruturais foi reespecificado e estimado utilizando o método de Máxima Verossimilhança e o procedimento bootstrap com 2000 reamostragens, até alcançar adequados valores dos índices de ajustamento. O modelo mostrou boa aderência às evidências empíricas, representando uma teoria explicativa dos fatores que influenciam o desempenho ambiental dos projetos de E&P na empresa estudada. As estatísticas descritivas apontaram adequado desempenho dos projetos de E&P com relação aos efluentes descartados, volume de água reutilizada, redução de resíduos e práticas de reciclagem. Identificou-se que projetos de maior porte alcançam melhor desempenho ambiental em relação aos de menor tamanho. Não foram achadas diferenças significativas entre os desempenhos de projetos executados por unidades operacionais distintas. Os resultados da modelagem indicaram que nem a legislação ambiental, nem os agentes externos exercem influência significativa sobre a sistemática da gestão dos projetos de E&P. Os agentes externos atuam sobre a gestão ambiental da empresa exercitando capacidades colaborativas, obstrutivas e propositivas. A legislação ambiental é percebida como entrave ao desenvolvimento dos projetos ao longo de seu ciclo de vida, principalmente, pelas deficiências dos órgãos ambientais. Identificou-se que o sistema de gestão ambiental influencia diretamente o Programa de Desenvolvimento e Execução de Projetos de E&P, que, por sua vez, provoca efeitos diretos e indiretos sobre o desempenho ambiental. Finalmente, comprovou-se que o Sistema de Gestão Ambiental da empresa é determinante para o desempenho ambiental dos projetos de E&P, tanto pelos seus efeitos diretos, como pelos indiretos, estes últimos mediados pela sistemática de gestão dos projetos de E&P

Monitoramento da morfologia costeira em setores da bacia potiguar sob influência da indústria petrolífera utilizando geodésia de alta precisão e laser escâner terrestre

The objective of this Doctoral Thesis was monitoring, in trimestral scale, the coastal morphology of the Northeastern coast sections of Rio Grande do Norte State, in Brazil, which is an area of Potiguar Basin influenced by the oil industry activities. The studied sections compose coastal areas with intense sedimentary erosion and high environmental sensitivity to the oil spill. In order to achieve the general objective of this study, the work has been systematized in four steps. The first one refers to the evaluation of the geomorphological data acquisition methodologies used on Digital Elevation Model (DEM) of sandy beaches. The data has been obtained from Soledade beach, located on the Northeastern coast of Rio Grande Norte. The second step has been centered on the increasing of the reference geodetic infrastructure to accomplish the geodetic survey of the studied area by implanting a station in Corta Cachorro Barrier Island and by conducting monitoring geodetic surveys to understand the beach system based on the Coastline (CL) and on DEM multitemporal analysis. The third phase has been related to the usage of the methodology developed by Santos; Amaro (2011) and Santos et al. (2012) for the surveying, processing, representation, integration and analysis of Coastlines from sandy coast, which have been obtained through geodetic techniques of positioning, morphological change analysis and sediment transport. The fourth stage represents the innovation of surveys in coastal environment by using the Terrestrial Laser Scanning (TLS), based on Light Detection and Ranging (LiDAR), to evaluate a highly eroded section on Soledade beach where the oil industry structures are located. The evaluation has been achieved through high-precision DEM and accuracy during the modeling of the coast morphology changes. The result analysis of the integrated study about the spatial and temporal interrelations of the intense coastal processes in areas of building cycles and destruction of beaches has allowed identifying the causes and consequences of the intense coastal erosion in exposed beach sections and in barrier islands

Effect of Urucu oil (Brazilian Amazon) on the biomass of the aquatic macrophyte Eichhornia crassipes (Mart.) Solms (Pontederiaceae)

Os rios e lagos de várzea da província petrolífera de Urucu, na Amazônia Central, são amplamente colonizados por macrófitas aquáticas, que podem ser afetadas por acidentes durante a exploração e o transporte de petróleo. Entre as macrófitas, a espécie flutuante Eichhornia crassipes (aguapé) ocorre abundantemente na região; OBJETIVO: O objetivo desse estudo foi verificar o efeito de diferentes dosagens do petróleo de Urucu (0; 0,5; 1,5 e 3,0 L.m-2) na biomassa viva e morta de E. crassipes e em algumas características físicas e químicas da água; MÉTODOS: O experimento teve oitenta e quatro dias de duração. A cada sete dias foi determinada a biomassa (viva e morta) de E. crassipes e os valores de temperatura, pH, condutividade elétrica e oxigênio dissolvido da água; RESULTADOS: A dosagem de 0,5 L.m-2 foi suficiente para causar mortalidade parcial (48%) em E. crassipes após trinta e cinco dias de exposição ao petróleo. A dosagem de 3,0 L.m-2 causou mortalidade total (100%) em E. crassipes em oitenta e quatro dias de exposição. A decomposição do petróleo e da biomassa morta de E. crassipes provocam a redução do oxigênio dissolvido e do pH, e aumento da condutividade elétrica e de fósforo total na água; CONCLUSÕES: Nós concluímos que um derramamento de petróleo pode provocar mortalidade total em uma população de uma espécie de macrófita, mas não em uma outra. Isto pode alterar a diversidade de espécies de macrófitas na região impactada. No caso de Eichhornia crassipes e Pistia stratiotes, um derramamento de petróleo de Urucu pode favorecer E. crassipes, a espécie menos sensível ao petróleo.

IIRSA: outro passo na pilhagem, exploração e (des) integração dos povos e territórios sul-americanos

La llamada Iniciativa para la Integración de Infraestructura Regional Suramericana (IIRSA) es un acuerdo multinacional celebrado entre los 12 países de América del Sur desde el año 2000, materializado a través de 10 ejes de comercialización orientados a la construcción de varios proyectos de infraestructura, que incluye la construcción de una enorme red de energía, de comunicación y transporte. Estos proyectos han sido financiados principalmente por los organismos multilaterales (BID, CAF, FONPLATA) profundizando la dependencia económica y política de los países involucrados, en especial mediante el aumento de la deuda externa, las empresas transnacionales garantizarán la infraestructura necesaria para la explotación más acentuada de nuestros recursos naturales y de la mano de obra barata, asegurando el abastecimiento de sus mercados. En este sentido, el discurso de crecimiento económico regional creará los mecanismos necesarios para la reproducción ampliada del sistema capitalista, mediante la promoción de la liberalización de los mercados internacionales, tales como intenta los Estados Unidos a través del Área de Libre Comercio de las Américas. En realidad, es un Desarrollo Regional de los países del Norte, un plan estratégico de ordenamiento territorial construido por transnacionales y dictado por el imperialismo de Norteamérica. Bajo la dirección del gobierno de Brasil ha sido implementado sigilosamente, para que los jefes de Estado, sin nombrarlo, ejecuten sus planes de desarrollo como parte de esta tan evidente estrategia de saqueo, entusiasmados y convencidos de que serán generosamente recompensados. Proclaman e inauguran proyectos de infraestructura que las empresas multinacionales y transnacionales consideran indispensables para el saqueo de los recursos naturales que aún quedan, después de cinco siglos de explotación continua de América Latina. En este sentido, nuestra investigación se volvió hacia el análisis de lo sector energético de lo Eje Perú-Brasil-Bolivia, por considerarlo de suma importancia para el mantenimiento de la explotación y consolidación hegemónica de las corporaciones multinacionales en América Latina

A tutela constitucional da exploração de petróleo em águas internacionais em face do princípio do desenvolvimento sustentável: a possibilidade de responsabilização civil do dano futuro

The demands brought by a society doomed to the constant production of global risks, which whose effects are not immediately noticed effects are not perceived immediately, claim from the Law a new Theory about the Risk, that would offer a broad environmental protection, at the same time it would still be compatible with the idea of economic efficiency, required by the Modern Industry. The expansion of the methods and technologies regarding the exploitation and production of oil causes the constant expansion of the exploitable boundaries, especially in ultra-deep waters with the Pre-salt layer, in Brazil, or the still incipient research about the polymetallic nodules and other mineral sources in international waters, like the Atlântico Sudoeste, by the Programme on Ocean Science in Relation do Non Living Resources (OSNLR), a global study performed in partnership with the Intergovernmental Oceanographic Commission, from UNESCO (IOC UNESCO) and also with the Division of Ocean Affairs and Law of the Sea (UNDOALOS). Thus, we aim to analyze the correlation, and possible collisions between the right to a balanced environment and the free exercise of economic activity and the occurrence of environmental damages from the perspective of the exploitation activities of oil and other natural resources in international waters, specifically in the Area, from the constitutional principle of sustainable development and its legitimacy by the environmental international protection. Therefore, this study also aims to evaluate the legal framework for exploration and production of oil in international waters, particularly in the Area, and appraise how the constitutional instruments and mechanisms for environmental protection can impact on the international environmental protection system in order to ensure the present and future generations an ecologically balanced environment, laid down in Article 225 of the Brazilian Constitution, even with so many risks posed by the activities of exploitation and production of oil in international waters. In the meantime, we intend to also intend to investigate the possibility of future liability for environmental damage in order to ensure that constitutional principle and, consequently, and try to define the concept of environmental damage and its implications on the constitutional principle of environmental protection. Given all that was in summary, this work aims to contribute to the evolution of the new Theory of Environmental Risk, turning the law into something more than a punitive or corrective element in this society, but into a legal risk management, that may be triggered even before the consolidation of the damage

A indústria petrolífera nacional e potiguar: uma análise a partir da tecnologia em E&P

O trabalho analisa a Indústria Petrolífera em três ambientes de atuação, mundial, nacional e estadual, a partir da observação de sete variáveis, a saber: caráter do petróleo; risco; economia de escala; integração; barreiras; tecnologia e ambiente. O estudo busca perceber as interações e os transbordamentos das variáveis selecionadas em cada um dos ambientes citados, em razão os aspectos econômicos e institucionais presentes nesta atividade, cujos resultados atingem diversos setores da economia e da sociedade como um todo e balizam o próprio processo de inovação da mesma. O estudo está alicerçado no arcabouço teórico neoschumpeteriano acerca dos aspectos voltados para concorrência e inovação, além da questão institucional, e se apóia em dados da Agência Nacional do Petróleo (A.N.P.), Ministério de Minas e Energia (MME), Movimento de Combate à Corrupção Eleitoral / Tribunal Superior Eleitoral (MCCE/TSE), Organization of the Petroleum Exporting Countries (OPEC), International Energy Agency (IAE), Institut Français Pétrole (IFP), United Nations Development Programme (UNDP). Avalia-se que em termos de caracterização da indústria petrolífera nos três ambientes considerados (mundial, nacional e local), há certa similitude no que se refere ao comportamento destas variáveis, com pequenas modificações suscitadas por fatores como grau de desenvolvimento e complexidade da atividade; resultado do ambiente concorrencial e inovativo; e, pelas influências institucionais acerca de atividades e grau de inserção das mesmas no ambiente socioeconômico onde estão localizadas a atividade produtiva e o seu entorno

Economia do petróleo e desenvolvimento: estudo exploratório sobre as perspectivas do pré-sal brasileiro

A pesquisa analisa as possibilidades abertas pela exploração de petróleo na camada pré-sal, avaliando de que maneira a expansão do setor petrolífero poderá acelerar o crescimento econômico brasileiro e contribuir para novas estratégias de desenvolvimento. A hipótese inicial é que o Brasil enfrenta uma restrição estrutural de balanço de pagamentos, que poderá ser amenizada pela diminuição das importações de petróleo e derivados e pelo aumento do valor exportado no setor. Para avaliá-la são resgatados aspectos históricos e geopolíticos relacionados ao petróleo, assim como são tratadas as características microeconômicas dos recursos naturais não renováveis. Também se consideram questões de ordem macroeconômica, como a especialização produtiva da economia brasileira e sua inserção no comércio internacional, discutindo como o desenvolvimento da indústria petrolífera poderá afetá-las. Para tanto, a investigação fundamenta-se na teoria estruturalista e nos modelos de crescimento com ênfase na restrição externa. O trabalho examina ainda os casos da Rússia, Venezuela e México para avaliar a experiência de países exportadores de petróleo. Como contribuição, um modelo de crescimento é utilizado para realizar simulações acerca do Brasil, cobrindo o período 2013-2020 com a formulação de três cenários. A partir dos resultados discute-se que a necessidade de consecução das metas fiscal e de inflação pode desencadear políticas restritivas que limitam a utilização da folga fiscal e externa, oriundas do pré-sal, para induzir o crescimento. Conclui-se que um círculo virtuoso de desenvolvimento com mudança estrutural depende não apenas da modernização produtiva, mas também, e principalmente, da evolução político-institucional do país

Possibilidades de exploração da história da ciência na formação do professor de matemática: mobilizando saberes a partir da obra de Nicolau Copérnico de revolutionibus orbium coelestium

This study aims to analyze the implications that the knowledge of an important work for the History of Science, De revolutionibus orbium coelestium , by Nicholas Copernicus, can bring for the formation of Mathematics professors. The study focuses on Book I of Copernicus s work, where, in the final part, is found the Table of the Subtense Straight Lines in a Circle, a true sine table constructed by the author. The study considers two theoretical references, the History of Science and of Mathematics, in the professor s formation searched amongst others in Miguel and Miorm, Brito, Neves and Martins, and Radford, and the necessary teaching knowledge professors mst have, on the basis of Gauthier, Schulman and Imbernón amongst others, through which it is established a net of knowledge grouped in dimensions such as mathematical, psycho pedagogical, cultural and practical diversity, that guide the study analysis. In the search for more necessary elements to enrich the analysis, beyond the theoretical research in Book I, it is carried through, with under graduation pupils, future Math professors, the construction of a sine table following the project used in De revolutionibus . The study still makes a description of the life and work of Nicholas Copernicus, detaching the historical context where the author lived and the conceptions about the Universe existing at that time. The research reveals that the studied work is an important source of culture, able to provide to the Mathematics professor in formation, beyond the conceptual and procedural mathematical knowledge, a cultural knowledge that allows him to be opened to the knowledge of other areas that not his specific area, and so to acquire knowledge about the world history, the development of sciences and of the society

Passivo ambiental e o setor de exploração de petróleo em terra: abordagem teórica e percepção institucional dos impactos ambientais gerados na atividade

The search for a sustainable development is result of the exhaustion of the natural resources of the planet that demands globalizated politics with practical of compatible economic development with the protection of the quality of life for the future generations. This work presents a study on the thematic on the environmental liabilities in the organizations with focus in the industry of the oil and the production of oil in land in the state of Rio Grande do Norte. Some types of environmental liabilities are presented, as well as, some estimates techniques. Moreover, this work presents surveys of some variable that stimulate the organizations to implant technologies of reduction of the impacts in the environment as: the environmental legislation, costs, the main impacts of the production of oil in land. On the basis of the bibliographical research and in the identified variable, it was carried a case study with state and municipal technician that act in the sectors of fiscalization (IBAMA-RN and IDEMA-RN) with the objective to deepen the discussion regarding the impacts of the industry of the oil, the effectiveness of the current law, the performance of the institutions the federal level and how to prevent impacts in the environment. It was observed that the environmental liabilities are a little spread subject in the organizations, perhaps to be unknown and of few theoretical referencees at the national level, regarding to the evaluation techniques. At the same time, absentee in the national politics that conducts the oil exploration

Algoritmo Q-learning como estratégia de exploração e/ou explotação para metaheurísticas GRASP e algoritmo genético

Techniques of optimization known as metaheuristics have achieved success in the resolution of many problems classified as NP-Hard. These methods use non deterministic approaches that reach very good solutions which, however, don t guarantee the determination of the global optimum. Beyond the inherent difficulties related to the complexity that characterizes the optimization problems, the metaheuristics still face the dilemma of xploration/exploitation, which consists of choosing between a greedy search and a wider exploration of the solution space. A way to guide such algorithms during the searching of better solutions is supplying them with more knowledge of the problem through the use of a intelligent agent, able to recognize promising regions and also identify when they should diversify the direction of the search. This way, this work proposes the use of Reinforcement Learning technique - Q-learning Algorithm - as exploration/exploitation strategy for the metaheuristics GRASP (Greedy Randomized Adaptive Search Procedure) and Genetic Algorithm. The GRASP metaheuristic uses Q-learning instead of the traditional greedy-random algorithm in the construction phase. This replacement has the purpose of improving the quality of the initial solutions that are used in the local search phase of the GRASP, and also provides for the metaheuristic an adaptive memory mechanism that allows the reuse of good previous decisions and also avoids the repetition of bad decisions. In the Genetic Algorithm, the Q-learning algorithm was used to generate an initial population of high fitness, and after a determined number of generations, where the rate of diversity of the population is less than a certain limit L, it also was applied to supply one of the parents to be used in the genetic crossover operator. Another significant change in the hybrid genetic algorithm is the proposal of a mutually interactive cooperation process between the genetic operators and the Q-learning algorithm. In this interactive/cooperative process, the Q-learning algorithm receives an additional update in the matrix of Q-values based on the current best solution of the Genetic Algorithm. The computational experiments presented in this thesis compares the results obtained with the implementation of traditional versions of GRASP metaheuristic and Genetic Algorithm, with those obtained using the proposed hybrid methods. Both algorithms had been applied successfully to the symmetrical Traveling Salesman Problem, which was modeled as a Markov decision process

Escalabilidade Paralela de um Algoritmo de Migração Reversa no Tempo (RTM) Pré-empilhamento

The seismic method is of extreme importance in geophysics. Mainly associated with oil exploration, this line of research focuses most of all investment in this area. The acquisition, processing and interpretation of seismic data are the parts that instantiate a seismic study. Seismic processing in particular is focused on the imaging that represents the geological structures in subsurface. Seismic processing has evolved significantly in recent decades due to the demands of the oil industry, and also due to the technological advances of hardware that achieved higher storage and digital information processing capabilities, which enabled the development of more sophisticated processing algorithms such as the ones that use of parallel architectures. One of the most important steps in seismic processing is imaging. Migration of seismic data is one of the techniques used for imaging, with the goal of obtaining a seismic section image that represents the geological structures the most accurately and faithfully as possible. The result of migration is a 2D or 3D image which it is possible to identify faults and salt domes among other structures of interest, such as potential hydrocarbon reservoirs. However, a migration fulfilled with quality and accuracy may be a long time consuming process, due to the mathematical algorithm heuristics and the extensive amount of data inputs and outputs involved in this process, which may take days, weeks and even months of uninterrupted execution on the supercomputers, representing large computational and financial costs, that could derail the implementation of these methods. Aiming at performance improvement, this work conducted the core parallelization of a Reverse Time Migration (RTM) algorithm, using the parallel programming model Open Multi-Processing (OpenMP), due to the large computational effort required by this migration technique. Furthermore, analyzes such as speedup, efficiency were performed, and ultimately, the identification of the algorithmic scalability degree with respect to the technological advancement expected by future processors

Avaliação da remoção de sulfeto de hidrogênio do gás natural em uma coluna de absorção

Natural gas, although basically composed by light hydrocarbons, also presents in its composition gaseous contaminants such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). Hydrogen sulfide, which commonly occurs in oil and gas exploration and production activities, besides being among the gases that are responsible by the acid rain and greenhouse effect, can also cause serious harm to health, leading even to death, and damages to oil and natural gas pipelines. Therefore, the removal of hydrogen sulfide will significantly reduce operational costs and will result in oil with best quality to be sent to refinery, thereby resulting in economical, environmental, and social benefits. These factors highlight the need for the development and improvement of hydrogen sulfide sequestrating agents to be used in the oil industry. Nowadays there are several procedures for hydrogen sulfide removal from natural gas used by the petroleum industry. However, they produce derivatives of amines that are harmful to the distillation towers, form insoluble precipitates that cause pipe clogging and produce wastes of high environmental impact. Therefore, the obtaining of a stable system, in inorganic or organic reaction media, that is able to remove hydrogen sulfide without forming by-products that affect the quality and costs of natural gas processing, transport and distribution is of great importance. In this context, the evaluation of the kinetics of H2S removal is a valuable procedure for the treatment of natural gas and disposal of the byproducts generated by the process. This evaluation was made in an absorption column packed with Raschig ring, where natural gas with H2S passes through a stagnant solution, being the contaminant absorbed by it. The content of H2S in natural gas in column output was monitored by an H2S analyzer. The comparison between the obtained curves and the study of the involved reactions have not only allowed to determine the efficiency and mass transfer controlling step of the involved processes but also make possible to effect a more detailed kinetic study and evaluate the commercial potential of each reagent