Yes / In this study, a Fuzzy Bayesian network (FBN) approach was proposed to analyze the domino effects of pool fire in storage tanks. Failure probabilities were calculated using triangular fuzzy numbers, the combined Center of area (CoA)/Sum-Product method, and the BN approach. Consequence modeling, probit equations, and Leaky-Noisy OR (L-NOR) gates were used to analyze the domino effects, and modify conditional probability tables (CPTs). Methanol storage tanks were selected to confirm the practical feasibility of the suggested method. Then the domino probability using bow-tie analysis (BTA), and FBN in the first and second levels was compared, and the Ratio of Variation (RoV) was used for sensitivity analysis. The probability of the domino effect in the first and second levels (FBN) was 0.0071472631 and 0.0090630640, respectively. The results confirm that this method is a suitable tool for analyzing the domino effects and using FBN and L-NOR gate is a good way for assessing the reliability of tanks. / National Petrochemical Company (NPC) of Iran

Light Non-Aqueous Phase Liquids (LNAPLs) are used throughout the world for numerous applications, the most well-known being automotive fuels, such as petrol and diesel. The widespread production, distribution, storage and use of LNAPLs results in the ubiquitous occurrence of spillage to ground (Geller et al, 2000). Considering the hazardous nature of most LNAPLs due to their explosive and toxic characteristics, releases of LNAPLs to ground have well documented human health and ecological consequences. The occurrence of leaking underground and above-ground storage tanks at service stations and consumer installations is a common cause of contamination; and is described in literature for various countries of the world (Dietz et. al., 1986; Moschini et al, 2005; Mulroy and Ou, 1997; Harris, 1989; The Institute of Petroleum, 2002). Little failure data are however available for the South African context. In addition to this, data concerning the location and characteristics of sites storing LNAPLs in South Africa is similarly scarce. The study analysed data from three sources, namely the eThekwini Fire and Emergency Services data, GIS data and data from a local consultancy, in order to determine whether certain factors increased contamination risk posed by these facilities. The results indicated that contamination may be a result of numerous factors, but primarily line and tank failure. The type of installation was also found to have a significant influence on whether a site would be contaminated or not. In addition to the above, the results indicated that certain circumstances increase the severity of loss. The results indicated the need for more investigation to be performed into contamination as a result of LNAPL loss to ground, and the need for protective measures to be implemented for high risk sites where the likelihood and severity of a potential loss is high. Focus should then be centred on the probability of failure of non-ferrous pipework and GRP tanks to ensure adequate protective mechanisms are in place in the event of a failure of this newer infrastructure. In addition, a review of regulatory control of LNAPL storage in South Africa and the eThekwini Municipality, with reference to the international context, indicated the need for a specific department within the local government structure that manages LNAPLs with the objective of reducing contamination incidents. The continued use of underground storage of LNAPLs will always present a risk of failure/contamination due to the unseen nature of the installations and related infrastructure. It is this risk that requires regulatory management. Details of contaminated sites in South Africa should be within the public domain. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

Univ., Diss.--Hamburg, 2006. / Literaturverz. S. [215] - 225.

Thesis (M. Sc.) (Hons) -- University of Western Sydney, 2003. / "A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science (Hons.), University of Western Sydney, Australia, Water Research Laboratory, Centre for Water & Environmental Technology." Includes bibliography : leaves 168 - 183 and appendices.

A injeção da água do mar nos campos marítimos (offshore), processo este conhecido como recuperação secundária de petróleo, gera muitos resíduos e efluentes. Dentre estes, pode-se destacar a água produzida, que consiste de água de formação, água naturalmente presente na formação geológica do reservatório de petróleo, e água de injeção, aquela normalmente injetada no reservatório para aumento de produção. Sete tanques de armazenamento de água/óleo de um terminal foram monitorados quanto à presença de micro-organismos e teores de sulfato, sulfeto, pH e condutividade. Particularmente, as bactérias redutoras de sulfato (BRS), que agem às expensas da atividade de outras espécies, reduzindo sulfato à sulfeto, constituindo-se num problema-chave. Os tanques de óleo codificados como Verde, Ciano, Roxo, Cinza, Vermelho, Amarelo e Azul, apresentaram comportamentos distintos quanto aos parâmetros microbiológicos e físico-químicos. Após este monitoramento, de acordo com valores referência adotados, e levando-se em conta como principais parâmetros classificatórios concentrações de BRS, bactérias anaeróbias totais e sulfeto, os dois tanques considerados mais limpos do monitoramento foram os tanques roxo e ciano. Analogamente, por apresentarem os piores desempenhos frente aos três principais parâmetros, os tanques amarelo e cinza foram considerados os mais sujos de todo o monitoramento. Após esta segregação, esses três principais parâmetros, mais a concentração de sulfato, foram inter-relacionados a fim de se corroborar esta classificação. Foi possível observar que o sulfeto instantâneo não foi o parâmetro mais adequado para se avaliar o potencial metabólico de uma amostra. Por este motivo, foram verificados os perfis metabólicos das BRS presentes nas amostras, confirmando a segregação dos tanques, baseada em parâmetros em batelada / Seawater injection for offshore petroleum recovery known as secondary petroleum, produces a high amount of residues and effluents. Among those waste solutions, produced water, consisting of formation water, naturally present during the geological formation of oil, and injection water, normally injected in the reservatory in order to increase oil recovery, deserves special attention. Seven water/oil storage tanks from an oil producing terminal were monitored for the presence of microorganisms, sulfate, sulfide, pH and conductivity. Particullarly, sulfate-reducing bacteria (SRB), acting with the help of other microbial species, deserve particular attention, due to its ability to reduce sulfate to sulfide. The storage tanks, coded as Green, Cyano, Purple, Gray, Red, Yellow and Blue, presented distinct behavior in relation to the microbiological and physico-chemical parameters. After the monitoring, according to reference values adopted for each parameter, and considering the main contribution of SRB cells, total anaerobic cells and sulfide, two tanks were considered the cleanest ones (purple and cyano). Analogously, considering the same parameters, the yellow and gray tanks were considered the dirtiest ones. After this initial segregation, those three main parameters and sulfate concentration were inter-related in order to corroborate the obtained classification for the tanks. It was possible to observe that sulfide concentration was not the most suitable parameter to be considered to predict the metabolic potential of a specific water sample. Due to this, the metabolic profiles of the SRB cells present in the samples were quantified, considering four tanks with different bacterial populations. This profile was consistent with the classification, confirming the segregation of the tanks, based on batch parameters

A injeção da água do mar nos campos marítimos (offshore), processo este conhecido como recuperação secundária de petróleo, gera muitos resíduos e efluentes. Dentre estes, pode-se destacar a água produzida, que consiste de água de formação, água naturalmente presente na formação geológica do reservatório de petróleo, e água de injeção, aquela normalmente injetada no reservatório para aumento de produção. Sete tanques de armazenamento de água/óleo de um terminal foram monitorados quanto à presença de micro-organismos e teores de sulfato, sulfeto, pH e condutividade. Particularmente, as bactérias redutoras de sulfato (BRS), que agem às expensas da atividade de outras espécies, reduzindo sulfato à sulfeto, constituindo-se num problema-chave. Os tanques de óleo codificados como Verde, Ciano, Roxo, Cinza, Vermelho, Amarelo e Azul, apresentaram comportamentos distintos quanto aos parâmetros microbiológicos e físico-químicos. Após este monitoramento, de acordo com valores referência adotados, e levando-se em conta como principais parâmetros classificatórios concentrações de BRS, bactérias anaeróbias totais e sulfeto, os dois tanques considerados mais limpos do monitoramento foram os tanques roxo e ciano. Analogamente, por apresentarem os piores desempenhos frente aos três principais parâmetros, os tanques amarelo e cinza foram considerados os mais sujos de todo o monitoramento. Após esta segregação, esses três principais parâmetros, mais a concentração de sulfato, foram inter-relacionados a fim de se corroborar esta classificação. Foi possível observar que o sulfeto instantâneo não foi o parâmetro mais adequado para se avaliar o potencial metabólico de uma amostra. Por este motivo, foram verificados os perfis metabólicos das BRS presentes nas amostras, confirmando a segregação dos tanques, baseada em parâmetros em batelada / Seawater injection for offshore petroleum recovery known as secondary petroleum, produces a high amount of residues and effluents. Among those waste solutions, produced water, consisting of formation water, naturally present during the geological formation of oil, and injection water, normally injected in the reservatory in order to increase oil recovery, deserves special attention. Seven water/oil storage tanks from an oil producing terminal were monitored for the presence of microorganisms, sulfate, sulfide, pH and conductivity. Particullarly, sulfate-reducing bacteria (SRB), acting with the help of other microbial species, deserve particular attention, due to its ability to reduce sulfate to sulfide. The storage tanks, coded as Green, Cyano, Purple, Gray, Red, Yellow and Blue, presented distinct behavior in relation to the microbiological and physico-chemical parameters. After the monitoring, according to reference values adopted for each parameter, and considering the main contribution of SRB cells, total anaerobic cells and sulfide, two tanks were considered the cleanest ones (purple and cyano). Analogously, considering the same parameters, the yellow and gray tanks were considered the dirtiest ones. After this initial segregation, those three main parameters and sulfate concentration were inter-related in order to corroborate the obtained classification for the tanks. It was possible to observe that sulfide concentration was not the most suitable parameter to be considered to predict the metabolic potential of a specific water sample. Due to this, the metabolic profiles of the SRB cells present in the samples were quantified, considering four tanks with different bacterial populations. This profile was consistent with the classification, confirming the segregation of the tanks, based on batch parameters

Orientador: José Roberto Nunhez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-22T21:36:55Z (GMT). No. of bitstreams: 1 TorresGaravito_AnaMilena_M.pdf: 2300264 bytes, checksum: 43e45d59aa30ab0f64716f86095c8a43 (MD5) Previous issue date: 2013 / Resumo: Frequentemente os processos de agitação e misturas tão fundamentais são negligenciados na indústria como um todo petroquímico, farmacêutica, química, de alimentos, etc. No entanto, existem sistemas em que o desempenho desses processos depende fortemente do grau de homogeneidade conseguido durante a mistura. Quando o processo de mistura não está devidamente projetado e controlado, obtêm-se misturas com flutuações significativas nas suas características físicas e/o químicas, que no geral são indesejáveis e que suscitam perdas de lotes inteiros de produtos, aumentando o custo e o impacto ambiental do processo de produção. O custo final da energia utilizada no processo de agitação e mistura depende de vários fatores, sendo um deles o impelidor empregado. Para analisar um processo são considerados fatores de interesse como: melhor agitação, menor tempo de mistura e menor potência consumida. Este trabalho de pesquisa teve como objetivo a determinação experimental do número de potência em função do número de Reynolds nos regimes turbulento e laminar para impelidores de proximidade tipo âncora (reta e tubular) com e sem raspadores e para um impelidor do tipo helicoidal, usando como fluido pseudoplástico de alta viscosidade a carboximetilcelulose (CMC) diluída em água. Desta forma, foi possível selecionar a configuração que apresentava o menor consumo de potência. Para isto foi utilizado o protótipo em escala piloto desenvolvido pelo grupo de pesquisa do laboratório de Fluidodinâmica Computacional (LCDF) da Faculdade de Engenharia Química da Unicamp / Abstract: Frequently, agitation and mixing processes, so fundamental ones, are neglected in the industry sector in general, such as petrochemical, pharmaceutical, chemical and food processing industries. However, there are systems in which the performance of the process depends strongly on the degree of homogeneity achieved during the mixing process. When the mixing process is not properly projected and controlled, mixtures with significant fluctuations regarding their physical and/or chemical characteristics are obtained, and been that usually undesirable, it may cause the loss of entire product batches, increasing the production cost and the environmental impact of the production process. The final cost of the energy used in the agitation process depends on several factors, being one of them the type of impeller used. In order to analyze any process, factors of interest such as better agitation, least mixing time and least power consumption are considered. This research aim is to experimentally determine the power number as a function of Reynolds number in turbulent and laminar regimes for anchor-type impellers (straight and tubular) with and without scrapers and for a helical-type impeller, using as a high viscosity pseudoplastic fluid the carboximethyl cellulose diluted in water. For this purpose, it was used a pilot plant scale prototype, developed by the research group of the Computational Fluid Dynamic Laboratory (LCFD) of the Chemical Engineering College at Unicamp / Mestrado / Desenvolvimento de Processos Químicos / Mestra em Engenharia Química

Orientadores: José Roberto Nunhez, Nicolas Spogis / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T06:34:09Z (GMT). No. of bitstreams: 1 CabralesNavarro_FredyAntonio_M.pdf: 2052593 bytes, checksum: d8d60c68b460ac2a2cd457e16a29e929 (MD5) Previous issue date: 2011 / Resumo: O processo de homogeneização de hidrocarbonetos em tanques de estocagem de grande escala equipados com impelidores de entrada lateral desempenha um papel importante na operação de uma refinaria, visto que a qualidade do produto final depende do desempenho deste processo. A Fluidodinâmica Computacional (CFD) é a técnica mais viável para avaliar e otimizar este processo, no qual o trabalho experimental é tecnicamente complicado e custoso. Neste trabalho, a técnica CFD é empregada para simular um tanque de estocagem de diesel a escala industrial com o uso do pacote comercial ANSYS CFX 13.0. A abordagem com múltiplos sistemas de referência (MFR) é empregada para modelar a movimentação do impelidor. Os efeitos turbulentos foram incorporados mediante o modelo de turbulência Shear Stress Transport (SST). Vários arranjos impelidor(es)/tanque obtidos variando o ângulo de deslocamento horizontal em relação à linha central do tanque são usados para avaliar a influência do número de impelidores e o seu posicionamento no desempenho do processo. Perfis hidrodinâmicos, consumos de potência, tempos de homogeneização e outros parâmetros relevantes para processos de mistura são utilizados para comparar os resultados. Baseando-se nos resultados das simulações, foi possível avaliar os diferentes cenários e determinar a condição mais apropriada para levar a cabo o processo. Considerando o consumo energético, a melhor configuração é utilizando um impelidor desviado 10 º e, levando em conta o tempo de homogeneização, o melhor arranjo é com três impelidores sem deslocamento. Adicionalmente, os prós e contras das alternativas foram discutidos e os resultados mais relevantes foram reportados / Abstract: The homogenization process of hydrocarbons in large scale storage tanks equipped with side-entry impellers plays an important role in a refinery operation, since the quality of the final products depends on the performance of this process. Computational Fluid Dynamics (CFD) is the most viable technique to evaluate and to optimize this process, as experimental work is technically complicated and expensive. In this work, the CFD technique is used to simulate an industrial diesel storage vessel using the commercial package ANSYS CFX 13.0. The Multiple Frames of Reference (MFR) approach is used to model the mixer movement. The turbulent effects are incorporated by means of the Shear Stress Transport (SST) turbulence model. Several impeller(s)/tank layouts obtained by varying the horizontal offset angle from the tank center line are used to assess the influence of the number of impellers and their positioning on the performance of the process. Hydrodynamic profiles, power consumptions, homogenization times and other relevant mixing parameters are also used to compare the results. Based on the computer simulation results, it was possible to evaluate the different scenarios and to determine the most appropriate conditions to carry out the process. Considering the power consumption, one impeller deviated 10° is the configuration with the best performance and, using three impellers without deviation is the arrangement that gives the shortest mixing time. In addition, the pros-and-cons of the other alternatives are discussed and the most relevant findings are reported / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

The topic of chemical oxidative degradation in rotational molded polyethylene (high-density cross-linked) chemical (sodium hypochlorite) storage tanks is an industry problem that ranks at the top of current business issues for manufacturers of chemical storage tanks. The degradation of these tanks not only compromises the physical and mechanical properties of the tank material, but reduces the life expectancy of the tank, eventually resulting in catastrophic tank failure. Premature tank failure comes at a hefty cost. The reputation of the manufacturer is questioned often resulting in immediate loss of customer satisfaction and future business. The leaking of the chemical from the failed tank serves as a liable environmental hazard that jeopardizes the safety and welfare of its surroundings – people and environment. And the associated manufacturer of the failed tank is almost certainly responsible for the repair or replacement of the tank. All these associated problems and many more related to chemical tank failure cost this relatively small industry millions of dollars annually. The need to determine the failure mechanisms of these tanks is critically important. Such an understanding will provide industry with useful knowledge that will open the door for improvements in tank performance. There is no question that a deeper understanding of failure mechanisms will improve a tank manufacturer's reputation, increase business sales, and assure environmental safety. The addition of this knowledge will also instill consumer confidence in an industry that is considered to lack refined manufacturing processes and proven quality controls. Such advancements are keys to making rotational molding a cutting-edge, technology-driven process that prepares industry for future growth and development. The purpose of this research is to provide tested empirical data and proven expert analysis that can be utilized by companies in understanding the failure mechanisms of these tanks. The information regarding this topic was collected from various tank samples taken from Poly Processing, a leading manufacturer of rotationally molded polyethylene chemical storage tanks and producer of the examined samples, and Odyssey Manufacturing, a manufacturer of bulk sodium hypochlorite and the end user of the examined samples. In the final chapter of this research, a summary is presented of the important findings regarding the purpose of the thesis study.

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