Dissertations / Theses on the topic 'Oil refineries'

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2006.
Includes bibliographical references (leaves 70-72).
The upstream petroleum supply chain is inefficient and uneconomical because of the independence of the four complex and fragmented functions which comprise it. Crude oil exploration, trading, transportation, and refining are functions which may be integrated through unified decision-making facilitated by timely information exchange. This exchange has been problematic because the four business units with their disparate activities have not been able to capture and appropriately structure the required information. How can business executives in the oil industry assemble all of the required information to achieve system-wide optimization? To remove the silos which impede system-wide optimization, there is need to analyze people, systems and issues in the upstream section of the petroleum supply chain; as a background to understanding the current challenges faced in achieving integration. Hence, the use of secondary and primary data sources was used for this research. The secondary includes the review of relevant literature while the primary data were from two sources. The first came from an on-site interview with the heads of business units of a case study, a company which is a major player in the industry.
(cont.) The second is from telephone interviews with industry experts which include software providers, consultants and other major players in the industry. The findings are that on-time information exchange will maximize shareholders' value and improve process efficiency in the supply chain. This process efficiency makes the upstream supply chain more responsive to possible changes in the environment that affects its operation. This will allow supply chain managers to achieve both a reduction in the variability in price of end product will be obtained while achieving stable profit margins. This research concludes by advocating that the use of information systems that accurately support data exchange among the functions in the supply chain in a timely, coordinated fashion with minimal distortion is required to ensure consistency in optimal decision making. To achieve this, change management is necessary because it requires a shift to a holistic approach in making decisions. Finally, areas recommended for future research are stated.
by Beatrice N. Nnadili.
M.Eng.in Logistics

A research study is undertaken to determine if economic incentives exist for noncompliance with regulatory standards, and if accounting related disclosure of regulatory enforcement actions is a determinant of environmental performance.

The aim of this thesis is to give suggestions on what measures to take to improve the VOC emission situation in refineries in Tianjin, China, through existing technologies in refineries in Sweden. This has been done by identifying the main places of leakage in oil refineries in Sweden, identifying what VOC compounds are emitted from the plants and the amounts emitted, mapping out different measures taken by oil refineries in Sweden to minimize VOC emissions, evaluating the different measures and suggesting how to move forward with VOC control in Tianjin. Six case studies have been done in Sweden; at Preemraff Lysekil, Shell refinery in Gothenburg, Berg depot Statoil Sweden situated in Nacka, Nynas refinery situated in Nynäshamn, Scandinavian Tank Storage situated in Torshamnen and Oxelösund harbor. Two case studies at Chinese refineries were made, PetroChina Dagang Petrohemical Company and China Petroleum and Chemical Corporation, Sinopec, Tianjin Branch, both situated in Tianjin Binhai New Area. Since the data retrieved from the Chinese refineries is insufficient to make a qualitative evaluation of the state of their VOC treatment it is not possible to propose measures for these two refineries. Instead this evaluation is focused on general problems and solutions at refineries and gives an idea of what can be done to improve the VOC emission situation at refineries. The report contains an evaluation of internal measures and technical solutions at Swedish refineries and other petrochemical companies. The evaluation is focused as much as possible on the Chinese situation. The technologies have been evaluated from an environmental, technical and economical point of view. This has resulted in recommendations for refineries that wish to enhance their VOC control.
Detta examensarbete har gjorts som en avslutande del i utbildningen Civilingenjör i Kemiteknik vid Kungliga Tekniska högskolan, Stockholm. Idén för arbetet introducerades av Östen Ekengren, IVL Svenska Miljöinstitutet, och har utförts vid IVL:s kontor i Stockholm. Den har handletts från Institutionen för Industriell Ekologi, KTH. Oljeraffinaderier släpper ut stora mängder VOC. På grund av den stora produktionsskalan och fabriksområdets omfattning är det svårt att veta hur mycket och vad som släpps ut. Lättflyktiga organiska ämnen (Volatile organic compounds, VOC) är organiska föreningar som har ett tillräckligt högt ångtrycker för att förångas under normala förhållanden. Stora mängder VOC läcker från oljeraffinaderier varje år. Tianjin är en industristad med stora investeringar. På grund av den stora industriella aktiviteten i området är VOC-problemen stora. En av de stora utsläppsbovarna är den petrokemiska industrin. Tianjin Academy of Environmental Science (TAES) har frågat efter Svensk teknik att minimera VOC-utsläpp från petrokemisk industri. Målet med detta examensarbete är att ge förslag på vilka åtgärder som kan tas för att förbättra VOC-utsläppssituationen i raffinaderier i Kina genom befintlig teknik på Svenska raffinaderier. Detta har gjorts genom följande steg: Identifiera de största utsläppsområdena på oljeraffinaderier i Sverige Identifiera vilka VOC-föreningar som emitteras från raffinaderierna samt i vilken mängd. Kartlägga olika åtgärder vid oljeraffinaderier i Sverige och i Tianjin, Kina för VOC-utsläpp. Utvärdera de olika åtgärderna och föreslå hur man kan gå vidare med VOC-kontroll i Kina. Sex fallstudier har genomförts i Sverige; Preemraff Lysekil, Shell raffinaderi i Göteborg, Bergs depot Statoil Sweden i Nacka, Nynas refinery i Nynäshamn, Scandinavian Tank Storage i Torshmnen och Oxelösunds hamn, Oxelösund. Två fallstudier har genomförts vid Kinesiska raffinaderier; PetroChina Dagang Petrochemical Comapany och China Petroleum and Chemical Corporation, Sinopec, Tianjin Branch, båda placerade i Tianjin Binhai New Area. Eftersom otillräcklig data från de Kinesiska raffinaderierna har gjort det svårt att göra en kvalitativ utvärdering av hur långt de kommit i VOC-arbetet har det inte varit möjligt att föreslå åtgärder för dessa två raffinaderier specifikt. Istället har utvärderingen fokuserats på generella problem och lösningar vid raffinaderier och att ge en ide om vad som kan göras för att förbättra VOC-utsläppssituationen vid raffinaderier. VOC från oljeraffinaderier med traditionell aktivitet består i huvudsak av alkaner, alkener och aromater där alkaner utgör den största delen. Alla dessa tre grupper förekommer naturligt i råolja. Vilka föreningar som förekommer i VOC-plymen från en fabriksanläggning beror på vilken råolja som används, hur processen ser ut och vilka produkter som produceras. Sammansättningen av VOC-plymen varierar därför från raffinaderi till raffinaderi. De största emissionskällorna vid raffinaderier som producerar i första hand bensin och diesel är tankparkerna, speciellt under fyllning. Tankparker som innehåller råolja utgör den största emissionspunkten vid dessa raffinaderier. Den näst största källan är processområdet. Detta medför att tankparker och processområde är de områden där störst fokus på minimering skall ligga för raffinaderier med samma typ av verksamhet. Produktionen vid Nynas Refinery kräver en annan råolja Här är det processen som utgör den största utsläppskällan tillsammans med vattenrening. Uppvärmda bitumencisterner utan rening utgör också en stor utsläppspunkt. Eftersom processområdet och tankparkerna har många potentiella läckpunkter är det primära sättet att minimera VOC-utsläpp tätning och underhåll på hela fabriksområdet. Införandet av rutiner för detta har visat sig mycket effektivt speciellt vid Shell raffinaderi. En annan idé skulle kunna vara att inkludera VOC-utsläppsmätning i on-line system för produktkvalitet. Detta skulle medföra ett inbyggt VOC-kontrollsysem. Detta har inte gjorts än men det kan vara värt att ta en närmare titt på. Kina har stort fokus på luktkontroll. Detta är bara en liten del av VOC-problemet. Metan utgör en stor del av utsläppen från råoljecisterner, vilka är vanliga luktbovar. För att eliminera lukt är adsorbtion med aktivt kol effektivt. Filtret fångar däremot inte kortare kolkedjor som metan och etan. För att eliminera dessa är förbränning den enda lösningen. Ingen luktsanerningsmetod som presenteras i denna rapport genererar någon vinst för företagen. Gasåterföringsanläggningar (VRU) har visats vara en gynnsam metod för att behandla emissioner vid tankning. En snabb överslagsräkning baserat på den återförda mängden bensin och diesel vid Preemraff Lysekil 2008 ger en vinst på 0,9 – 1,3 miljoner Euro/år. En stor andel VOC förbränns i fackla på raffinaderier. Denna gas skulle kunna användas som bränngas eller för energiåtervinning. Penningvärdet på energin i gasen som facklas är stor. Genom att installera en kompressor kan gas som skulle facklas användas som bränngas i raffinaderierna istället. Båda de studerade raffinaderierna i Kina angav fackling som den primära VOC-åtgärden. Man kan därmed anta att stora mängder gas facklas där. Detta visar att det finns mycket att tjäna på att hitta alternativa sätt att använda gasen. Flyktiga utsläpp är en stor del av VOC-källorna vid oljeraffinaderier. Utsläppunkterna beror på typ av råolja, process och produkter. Varje raffinaderi ar unikt och måste därför mäta sin a utsläpp. Vid mätning av ett helt fabriksområde med Solar Occulation Flux-metoden, som är en on-lineteknik som mäter VOC-utsläpp i from av alkaner, fås en bild av totala utsläppen från hela fabriken. Detta är till stor hjälp vid identifiering av problemområden och behandling av dessa. När VOC-behandling skall påbörjas vid ett raffinaderi rekommenderas följande: Mätning av VOC över hela raffinaderiområdetAnvända on-lineteknik, så som SOF Identifiera sammansättning av plymen genom kanisterprov etc. Läcksökning / Underhåll Om följande tekniska lösningar går att applicera vid raffinaderiet föreslås det att de prioriteras. Införa VRU-anläggning Energiåtervinning (minimerad fackling) Införa kommunicerande kärl För fortsatt arbete rekommenderas följande. Undersöka om det finns intresse och möjlighet att införa on-line VOC-konrollsystem eller on-line konstrollsystem för produktkvalitet. Är det tekniskt möjligt och ekonomiskt hållbart? För att kunna utvärdera miljöpåverkan av NMVOC från oljeraffinaderier har en studie av effekterna från emissionerna från Preemraff Lysekil och Shell Göteborg gjorts genom att använda karakteriseringsdata från databaserna CLM2001 och EDIP97. Detta resulterade i ett värde som ger hur många gånger fler de två raffinaderierna per ton satsad råolja bidrar till ozonformationspotentialen och globala uppvärmningspotentialen i förhållande till årspersonsekvivalenten (vad en normalperson bidrar med per år). Det visade sig att de bidrar med mycket mindre än årspersonsekvialenten per ton råolja, 0,03 gåner för Preemraff och 0,02 gånger för Shell. Men med antalet ton råolja som processas per år i åtanke så blir oljeraffinaderierna en stor källa till miljöpåverkan. Toxicitetsvärdena visade att Shell hade mycket större andel toxiska utsläpp än Preemraff. I förbränning, som fackling, så förbränns VOC till CO2. Detta medför att VOC har en sekundär GWP. Om hänsyn tas till detta kan man se att den totala GWP av VOC främst utgörs av den sekundära effekten genom fackling. Denna utvärdering visar att miljöpåverkan är olika för olika raffinaderier, även de med samma typ av verksamhet.

Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil Gestão e Sistemas Ambientais
Industrial symbiosis is an application of industrial ecology that consists of a collaborative approach between different industries and firms aimed at improving their environmental and economic performance involving the exchange of waste/byproducts as substitutes for raw materials. This collaboration is conditioned by the geographic proximity between industries and may face some information, economic, regulatory or motivational barriers. The main objective of this thesis was to develop a methodology to find and evaluate new potential exchanges in light of industrial symbiosis and to apply it to Sines oil refinery case study. The methodology was divided into four phases. The first phase is where, through the analysis of similar case studies, the potential new exchanges are uncovered.The second was made based on a literature review on the main barriers to industrial symbiosis development. This phase was developed to swiftly filter potential synergies that would face barriers to its development. The other two phases were only applied to the potential synergies that successfully passed the “filter”. Those phases consisted of an environmental evaluation through a LCA and a financial analysis. The application of the methodology showed two new potential synergetic possibilities for the Sines oil refinery. The results of the evaluation of those potential synergies were very promising both environmentally and financially. This research thus demonstrates the potential and benefits associated with the development of industrial symbiosis networks if the barriers to this development can be successfully surpassed.

The influence of catalyst characteristics, i.e., acidity and porosity on the product distribution in the cracking of triglyceride-rich biomass under fluid catalytic cracking (FCC) conditions is reported. It has found that the degradation degree of triglyceride molecules is strongly dependent on the catalysts’ acidity. The higher density of acid sites enhances the conversion of triglycerides to lighter products such as gaseous products and gasoline-range hydrocarbons. The formation of gasolinerange aromatics and light olefins (propene and ethene) is favored in the medium pore channel of H-ZSM-5. On the other hand, heavier olefins such as gasoline-range and C4 olefins are formed preferentially in the large pore structure of zeolite Y based FCC catalyst (Midas-BSR). With both catalysts, triglyceride molecules are mainly converted to a mixture of hydrocarbons, which can be used as liquid fuels and platform chemicals. Hence, the utilization of the existing FCC units in conventional petroleum refineries for processing of triglyceride based feedstock, in particular waste cooking oil may open the way for production of renewable liquid fuels and chemicals in the near future
Bài báo trình bày kết quả nghiên cứu khả năng tích hợp sản xuất nhiên liệu sinh học và hóa phẩm từ nguồn nguyên liệu tái tạo sinh khối giầu triglyceride bằng công nghệ cracking xúc tác tấng sôi (FCC) trong nhà máy lọc dầu. Kết quả nghiên cứu cho thấy xúc tác có ảnh hưởng mạnh đến hiệu quả chuyển hóa triglyceride thành hydrocarbon. Tính acid của xúc tác càng mạnh thì độ chuyển hóa càng cao và thu được nhiều sản phẩm nhẹ hơn như xăng và các olefin nhẹ. Xúc tác vi mao quản trung bình như H-ZSM-5 có độ chọn lọc cao với hợp chất vòng thơm thuộc phân đoạn xăng và olefin nhẹ như propylen và ethylen. Với kích thước vi mao quản lớn, xúc tác công nghiệp FCC dựa trên zeolite Y ưu tiên hình thành C4 olefins và các olefin trong phân đoạn xăng. Ở điều kiện phản ứng của quá trình FCC, triglyceride chuyển hóa hiệu quả thành hydrocarbon mà có thể sử dụng làm xăng sinh học cho động cơ và olefin nhẹ làm nguyên liệu cho tổng hợp hóa dầu

The influence of catalyst characteristics, i.e., acidity and porosity on the product distribution in the cracking of triglyceride-rich biomass under fluid catalytic cracking (FCC) conditions is reported. It has found that the degradation degree of triglyceride molecules is strongly dependent on the catalysts’ acidity. The higher density of acid sites enhances the conversion of triglycerides to lighter products such as gaseous products and gasoline-range hydrocarbons. The formation of gasolinerange aromatics and light olefins (propene and ethene) is favored in the medium pore channel of H-ZSM-5. On the other hand, heavier olefins such as gasoline-range and C4 olefins are formed preferentially in the large pore structure of zeolite Y based FCC catalyst (Midas-BSR). With both catalysts, triglyceride molecules are mainly converted to a mixture of hydrocarbons, which can be used as liquid fuels and platform chemicals. Hence, the utilization of the existing FCC units in conventional petroleum refineries for processing of triglyceride based feedstock, in particular waste cooking oil may open the way for production of renewable liquid fuels and chemicals in the near future.
Bài báo trình bày kết quả nghiên cứu khả năng tích hợp sản xuất nhiên liệu sinh học và hóa phẩm từ nguồn nguyên liệu tái tạo sinh khối giầu triglyceride bằng công nghệ cracking xúc tác tấng sôi (FCC) trong nhà máy lọc dầu. Kết quả nghiên cứu cho thấy xúc tác có ảnh hưởng mạnh đến hiệu quả chuyển hóa triglyceride thành hydrocarbon. Tính acid của xúc tác càng mạnh thì độ chuyển hóa càng cao và thu được nhiều sản phẩm nhẹ hơn như xăng và các olefin nhẹ. Xúc tác vi mao quản trung bình như H-ZSM-5 có độ chọn lọc cao với hợp chất vòng thơm thuộc phân đoạn xăng và olefin nhẹ như propylen và ethylen. Với kích thước vi mao quản lớn, xúc tác công nghiệp FCC dựa trên zeolite Y ưu tiên hình thành C4 olefins và các olefin trong phân đoạn xăng. Ở điều kiện phản ứng của quá trình FCC, triglyceride chuyển hóa hiệu quả thành hydrocarbon mà có thể sử dụng làm xăng sinh học cho động cơ và olefin nhẹ làm nguyên liệu cho tổng hợp hóa dầu.

A proposta desta pesquisa foi avaliar a utilização de um sistema combinado de filtro anaeróbio (FAN) com filtro aeróbio (FAE) submerso ligados em série, ambos usando espuma de poliuretano como meio suporte e com fluxo ascendente, como alternativa para remoção matéria orgânica (DQO) e compostos nitrogenados em efluentes de refinarias de petróleo, além da redução da toxicidade do efluente ao micro crustáceo Mysidopsis juniae. O experimento durou 324 dias e foi divido em duas etapas. Inicialmente, o sistema foi operado por 129 dias sem recirculação entre os filtros e nesta etapa houve acréscimo de 12% nas concentrações de amônia no FAN e remoção de 80% no FAE. Quando se usou bicarbonato de sódio para alcalinizar o afluente ao sistema para manter o pH no FAE na neutralidade e alcalinidade acima de 107 mg\'CA\'CO IND.3\'/L, pôde-se alcançar remoções de amônia próxima a 100%. Quanto à remoção de DQO, o filtro anaeróbio removeu 40% e o aeróbio 65%. Em síntese, na primeira etapa o sistema removeu 80% de DQO, 89% de amônia e 35% de nitrogênio. A segunda etapa durou 195 dias e houve recirculação do efluente do filtro aeróbio para o filtro anaeróbio. Nesta etapa, o pH foi mantido na neutralidade e a recirculação foi feita de duas formas. A primeira com recirculação direta entre os filtros a uma razão (R) de reciclo de 2,0 resultou em 43% de remoção de amônia no FAN e 97% no FAE e com esta forma de reciclo houve 62,6% de remoção de nitrogênio total no sistema. A segunda forma de recirculação foi direcionar parte do efluente do filtro aeróbio ao reservatório do afluente ao sistema com R igual a 1,0 resultando em produção de amônia no FAN em 10% e remoção no FAE de, aproximadamente, 100%. Independentemente da forma de recirculação a remoção de DQO foi de 67% e 56% no filtro anaeróbio e aeróbio, respectivamente. A remoção de nitratos no FAN foi de 93% e foi independente da forma de reciclo. Houve 42,5% de remoção de nitrogênio no sistema. Na segunda etapa obtiveram-se as melhores remoções de DQO, amônia e nitrogênio, porém, tanto o afluente quanto o efluente final apresentou CL50 de 0,83% ao microcrustáceo M. juniae, assim, ambas as formas do efluente estão em desacordo com a resolução CONAMA 357/05. Os gêneros Aeromonas, Serratia e Pseudomonas foram dominantes no FAE ao fim da pesquisa.
The purpose of this study was to evaluate the use of a combined system comprised of an anaerobic filter (ANF) and a submerged aerobic filter (SAF) connected in series, both using polyurethane foam as support media and operated in a upflow mode, as an alternative for removing organic matter (COD) and nitrogen compounds in effluents from oil refineries, as well as reducing effluent toxicity to micro crustacean Mysidopsis juniae. The experiment lasted 324 days and was divided into two stages. Initially, the system was operated for 129 days without recirculation between the filters. During this stage, there was an increase of 12% on the ammonia content in the ANF followed by a removal of 80% in the SAF. When sodium bicarbonate was used to alkalize the influent to maintain the pH in the ANF close to neutral and alkalinity above 107 mg\'CA\'CO IND.3\'/L, the removal efficiency of ammonia reached values close to 100%. Regarding to COD removal, the ANF removed 40% and SAF removed 65%. In summary, in the first stage of the research the system removed 80% of COD, 89% of ammonia and 35% of nitrogen. The second stage lasted 195 days and there was a recirculation line from the SAF to the ANF. In this step, the pH was maintained close to neutral and recirculation was done in two different ways. In the first, the recirculation flow was conducted from the SAF direct to the ANF at a rate of 2.0, which resulted in 43% removal of ammonia in the ANF and 97% in the SAF. Moreover, with this form of recycling 62.6% of the total nitrogen was removed from the system. The second way was to direct part of the effluent of the SAF to the tank that contained the influent of the ANF. In this case, the recirculation rate was 1.0, and resulted in a production of 10% of ammonia in the ANF and removal of approximately 100% in the SAF. Independently of the way used for recirculation, the COD removal efficiencies was 67% and 56% in ANF and SAF, respectively. The removal of nitrate in the ANF was 93% and was independent of the form of recycling. There was a 42.5% removal of nitrogen in the system. In the second stage occurred the best removals of COD, ammonia and nitrogen. However, both the affluent and the effluent had LC50 of 0.83% to microcrustacean M. juniae. Therfore, both forms of the effluent are in disagreement with the Brazilian law Resolução CONAMA 357/05. The Aeromonas, Serratia and Pseudomonas were dominant in the SAF at the end of research.

Orientador: Arnaldo César da Silva Walter
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A conexão entre o desempenho das empresas de petróleo e as mudanças climáticas, tomando por base a literatura disponível, constitui-se numa relação pouco estudada, apesar de fundamental quando se discutem as condições de adaptação e mitigação do aquecimento global. Este trabalho trata da análise das ações tomadas em relação às mudanças climáticas por quatro grandes empresas de petróleo escolhidas (BP - British Petroleum, Shell e Statoil), escolhidas devido às suas posições estratégicas nos mercados locais e internacionais, bem como pela Petrobras, de forma a se estabelecer uma análise comparativa entre essas empresas. Para tanto foram investigadas as questões científicas das mudanças climáticas, sem se esquecer de seus críticos, assim como a relação entre energia e mudanças climáticas segundo os cenários do Energy Information Administration - EIA (do governo dos EUA) para o ano de 2008. São analisados também os cenários de contextualização, baseados nos seguintes documentos: Energy Technology Perspectives 2008, da Agência Internacional de Energia (IEA), que reporta cenários de mitigação das emissões de gases de efeito estufa tendo como horizonte 2050; documentos de campanha dos então candidatos Barack Obama e Joe Binden, atualmente presidente e vice dos EUA, respectivamente; documentos da União Européia (Directives EU) e do governo da Califórnia (California Air Resources Board), Um quadro comparativo permite verificar e concluir se as ações das empresas de petróleo estão de acordo com os cenários previstos e quais ações devem ser tomadas pela Petrobras buscando um posicionamento em seu planejamento estratégico. Uma das principais contribuições deste trabalho está em posicionar as empresas estudadas diante das mudanças climáticas, respondendo a quatro perguntas fundamentais formuladas no início do estudo
Abstract: Only modest literature data are available on the connection between the performance of oil companies and the climate changes, although this connection is crucial when discussing the conditions for adaptation and mitigation to global warming changes. This investigation report deals with the analysis of the actions taken in relation to climate change by four major oil companies BP - British Petroleum, Shell and Statoil, selected due to their strategic positions in the local and international markets, and also by Petrobras, in order to establish a comparison among these companies. The scientific issues of climate changes are investigated herein, but not forgetting of its their critics, as well as the relationship between energy and climate change scenarios according to the Energy Information Administration - EIA (the U.S. government) for the year 2008. The contextual scenarios of this investigation are also analyzed based on the following documents: Energy Technology Perspectives 2008, the International Energy Agency (IEA), which reports emissions scenarios for mitigation of greenhouse gases with the horizon in 2050, documents the campaign of the candidates Barack Obama and Joe Binden, documents of the European Union (EU Directives) and the government of California (California Air Resources Board), A comparative table allows someone to verify and conclude if the actions taken by the oil companies are complying with the envisaged scenarios and what actions should be taken by Petrobras in order to seek a position in its strategic planning. One of the main contributions of this work is to rank the studied companies by taking into account the climate changes. This ranking answers four key questions prepared at the beginning of the study
Doutorado
Planejamento de Sistemas Energeticos
Doutor em Planejamento de Sistemas Energéticos

Orientador: Wilson de Figueiredo Jardim
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Mestrado
Quimica Analitica
Mestre em Química

Traditionally when purchasing new products, the number one priority is to choose the conforming product with the lowest purchase cost. Companies procuring new equipment know that other expenses, such as those related to maintenance, are going to add significantly to the cost in the long run, but they are often unable to quantify these costs. For this reason they are limited to making the decisions solely on the initial purchase costs. Life Cycle Costing enables the purchaser to assess the products using the costs occurred over the entire life of the product. This paper discusses the benefits associated with the use of Life Cycle Costing (LCC) principles in the procurement of equipment. A LCC method for the acquisition of equipment is introduced. Included in this method is a freestanding computer program which calculates and produces results which aid in the analysis process.

Thesis submitted in partial fulfilment of the requirements for the degree Master of Technology: Chemical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2013
In South Africa, the Department of Environmental Affairs (DEA) under the National Environmental Management Act, 1998 (Act 107 of 1998) (“NEMA”) sets out a series of environmental management principles that apply to the interpretation and application of all legislation that may affect the environment. Since 1998, various specific environmental statutes that fall under the NEMA framework have been promulgated, including the National Environmental Management: Air Quality Act, Act 39 of 2004 (NEM: AQA).NEM:AQA provides norms and standards for all technical aspects of air quality management. The National Framework (Sections 7 and 8 of NEM:AQA) must provide mechanisms, systems and procedures to promote holistic and integrated air quality management through pollution prevention and minimisation at source, and through impact management with respect to the receiving environment, from local scale to international issues. Among other measures, the NEM:AQA (Section 9) requires the establishment of Ambient Air Quality Standards and Emission Standards. These standards were promulgated in December 2009 and March 2010 respectively. Air quality monitoring stations, which sample and analyse pollutant concentrations continuously, are a common method of assessing air quality in a region. But a few continuous monitors located in source given region or airshed are inadequate for assessing compliance with ambient air quality standards – they are only able to monitor concentrations at a fixed site, not through the entire region of impact. In contrast, the ambient air quality standards are applicable everywhere. Air quality models estimate ground level ambient concentrations throughout the modelling domain, and in principle (subject to proper validation) provide better estimates of area-wide concentrations and hence the basis for assessing compliance with air quality standards. The United States Environmental Protection Agency (US EPA) approved atmospheric air dispersion models AERMOD and CALPUFF were used in this thesis to predict the ground level concentrations of SO2 emitted from Chevron Refinery (Cape Town), for the year 2010. The modelling is validated by comparing measured ambient concentrations with modelled concentrations. The results showed AERMOD-modelled annual average values for 2010, based on refinery emissions only, are in good agreement with monitored values at the Table View and Bothasig sites, predicting the monitored values by -11% and +17% respectively. The 24-hr average values similarly are in good agreement with monitored values, on average over-predicting by 9% at Table View, although the fit of the day-to-day modelled vs monitored values is comparatively poor (R2=0.32); at the Bothasig site the corresponding values are - 36% and R2= 0.089. The AERMOD-modelled isopleths imply that the 2010 annual average concentrations exceeded the South African Standard of 50 μg/m3 in a small area in the immediate vicinity of the refinery. The hourly and 24-hourly average standard concentrations of 350μg/m3 and 125μg/m3 respectively are exceeded in significantly larger areas. The allowable exceedences for hourly and 24-hourly averages are also exceeded, implying that the hourly and 24-hourly standards were exceeded. CALPUFF-modelled average values for 2010, based on refinery emissions only, are in comparatively poor agreement with monitored values at the Table View and Bothasig sites, under-predicting the monitored values by -20% and -61% respectively. Since the AERMOD-modelled concentrations are in far better agreement with monitored concentrations, only AERMOD was used for further analysis. The Emission Standards promulgated in March 2010 included emission limit values for sulphur dioxide emitted from oil refineries. If the actual 2010 emission rates were adjusted downwards to match the emission standards (to be complied with from 1 April 2015), AERMOD modelling indicates that the annual, 24-hourly and hourly Ambient Air Quality Standards would not be exceeded. Based on this case study, the current Emission Standard for SO2 emissions from existing crude oil refineries is therefore coherent with the Ambient Air Quality Standards. Regulatory air dispersion modelling practices in South Africa are being standardised for model applications regulatory purposes and to ensure that dispersion modelling practices are undertaken in a compatible form to ensure that results from one dispersion model study can be compared directly to those from another. In this study both AERMOD and CALPUFF modelling complied with the draft South African guidelines for Air Quality Modelling, yet the CALPUFF- modelled outputs differed significantly from the monitored values. This emphasizes the importance of the inclusion of modelling validation in guidelines for modelling for regulatory purposes. The 2012 draft regulation should be amended to make validation of regulatory dispersion modelling compulsory rather than optional as per the draft.

Through the Global Gas Flaring Reduction (GGFR) initiative a substantial amount of effort and international attention has been focused on the reduction of gas flaring since 2002 (Elvidge et al., 2009). Nigeria is rated as the second country in the world for gas flaring, after Russia. In an attempt to reduce and eliminate gas flaring the federal government of Nigeria has implemented a number of gas flaring reduction projects, but poor governmental regulatory policies have been mostly unsuccessful in phasing it out. This study examines the effects of pollution from gas flaring using multiple satellite based sensors (Landsat 5 TM and Landsat 7 ETM+) with a focus on vegetation health in the Niger Delta. Over 131 flaring sites in all 9 states (Abia, Akwa Ibom, Bayelsa, Cross Rivers, Delta, Edo, Imo, Ondo and Rivers) of the Niger Delta region have been identified, out of which 11 sites in Rivers State were examined using a case study approach. Land Surface Temperature data were derived using a novel procedure drawing in visible band information to mask out clouds and identify appropriate emissivity values for different land cover types. In 2503 out of 3001 Landsat subscenes analysed, Land Surface Temperature was elevated by at least 1 ℃ within 450 m of the flare. The results from fieldwork, carried out at the Eleme Refinery II Petroleum Company and Onne Flow Station, are compared to the Landsat 5 TM and Landsat 7 ETM+ data. Results indicate that Landsat data can detect gas flares and their associated pollution on vegetation health with acceptable accuracy for both Land Surface Temperature (range: 0.120 to 1.907 K) and Normalized Differential Vegetation Index (sd ± 0.004). Available environmental factors such as size of facility, height of stack, and time were considered. Finally, the assessment of the impact of pollution on a time series analysis (1984 to 2013) of vegetation health shows a decrease in NDVI annually within 120 m from the flare and that the spatio-temporal variability of NDVI for each site is influenced by local factors. This research demonstrated that only 5 % of the variability in δLST and only 12 % of the variability in δNDVI, with distance from the flare stack, could be accounted for by the available variables considered in this study. This suggests that other missing factors (the gas flaring volume and vegetation speciation) play a significant role in the variability in δLST and δNDVI respectively.

Thesis (MBA)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: The oil industry is under pressure to select refinery projects that will provide higher and more predictable returns. In the past Discounted Cash Flow (DCF) techniques have been used to choose between refinery project alternatives. One of the problems with DCF techniques is that they ignore management flexibility when evaluating projects that contain embedded options. Real Option Valuation (ROV) is an approach that takes management flexibility into account and places a value on this flexibility. ROV has been used extensively by the oil industry for the evaluation of oil and gas reserves. The aim of this study is to determine the extent to which the use of ROV will improve the decision making process when evaluating a refining project containing embedded options as well as to determine the most appropriate option valuation method for refining projects. This was done by evaluating a refining project using both a probabilistic DCF approach and the various option pricing models and comparing the results. It was concluded that ROV will improve the decision making process when evaluating refining projects containing embedded options. The most appropriate option pricing method for refining projects was found to be the simulation approach since simulation is already being used by refineries to perform probabilistic DCF analysis. It is not recommended that ROV should be blindly applied to all refining projects containing embedded options. The use of ROV should be limited to larger refining projects for which probabilistic cash flows have been developed and the extent of the ROV analysis required should be determined by a careful review of the net present value (NPV) cumulative probability curves.
AFRIKAANSE OPSOMMING: Die olie industrie is onder druk geplaas om projekte te kies met 'n hoër opbrengs op kapitaal en 'n opbrengs wat meer voorspelbaar is. In die verlede is slegs die Verdiskonteerde Kontant Vloei (VKV) metode gebruik om projekte te selekteer vir die raffinadery. Een van die onderliggende tekortkominge met die gebruik van die VKV metode is dat verskillende bestuursopsies in terme van alternatiewe met ingeboude opsies, nie voldoende ondersoek word nie. Reële Opsie Waardasie (ROW) is 'n metode wat bestuursopsies in ag neem deur 'n waarde te plaas op elke beskikbare bestuursopsie. ROW het wye toepassings in die olie industrie vir die evaluasie van gas en olie reserves. Die doel van hierdie studie is om te bepaal tot watter mate die gebruik van ROW die besluitnemingsproses sal verbeter in terme van die evaluasie van projekte met ingeboude opsies vir raffinaderye en watter opsiewaardasie metode die mees geskikte is vir sulke projekte. 'n Raffinadery projek is evalueer deur beide KV en verskeie opsie-prysbepalingsmetodes te gebruik en die resultate is vergelyk. Die resultate van die studie het bewys dat die ROW metode die besluitnemingsproses verbeter. Die studie het gewys dat die mees geskikte opsie-waardasie metode vir projekte in the raffinadery die simulasie benadering is omdat simulasie alreeds vir probalisties VKV ontleding gebruik word. 'n Verdere aanbeveling is dat die ROW metode nie blindelings gevolg moet word vir alle projekte met ingeboude opsies nie. Die gebruik van ROW moet beperk word tot groter projekte waarvoor probabilistiese kontantvloei alreeds ontwikkel is. Die mate van ROW ontleding moet bepaal word deur 'n noukeurige ondersoek te doen van die kumulatiewe netto huidige waarde-waarskynlikheidskurwe.

Orientador: Arnaldo Cesar da Silva Walter
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Queima de combustíveis fósseis é a principal contribuição humana para o aquecimento global. Neste trabalho foram investigadas oportunidades de redução das emissões de gases de efeito estufa (GEE) para uma refinaria brasileira de petróleo, através das seguintes etapas: levantamento das estratégias de enfrentamento do problema adotadas por algumas empresas; seleção de uma metodologia de estimativa de emissões de GEE para companhias de óleo e gás; elaboração do inventário da refinaria nacional através do programa aplicativo SANGEA; e proposição de opções para gestão das emissões de GEE dessa refinaria. Combustão e práticas de flaring e venting são os maiores contribuintes das emissões de GEE da cadeia produtiva. Quatro opções de mitigação estão sendo exploradas pelas empresas: aumento da eficiência energética, redução de flaring e venting, mudança para fontes energéticas menos intensivas em carbono e seqüestro de carbono. Neste estudo foi mostrado que o SANGEA é uma ferramenta de estimativa adequada, pois a emissão total de GEE obtida apresentou uma diferença de 1% em relação ao valor estimado pela Petrobrás. Melhoria da eficiência energética é a principal oportunidade de redução de emissões. Para a refinaria estudada foram descritos futuros projetos da área energética que apresentaram um potencial de emissão evitada de 270.000 t CO2 /ano. Por outro lado, a instalação de novas unidades para adequação dos teores de enxofre da gasolina e do diesel resultará na emissão adicional de 208.000 t CO2 /ano. Portanto, o sucesso dos esforços para economizar energia pode ser anulado pelas exigências ambientais para adequação da qualidade dos produtos. Isto ressalta a necessidade dos formuladores de política estabelecer um balanço entre as novas exigências para combustíveis (com impactos locais) e a política de abatimento de CO2 (com impactos globais)
Abstract: Fossil fuel burning is the main human contribution to global warming. In this study, opportunities for reducing greenhouse gas (GHG) emissions were investigated for a Brazilian oil refinery, according to the following steps: survey of climate change strategies adopted by some companies; selection of a methodology for calculating GHG emissions for the petroleum industry; development of an inventory for a national oil refinery by applying SANGEA software; and proposal of options for managing GHG emissions in this refinery. Combustion, flaring and venting are the largest contributors to GHG emissions in the production chain. Four mitigation options are being explored by companies: increasing energy efficiency, flaring and venting reduction, switching to less carbon-intensive sources of energy and carbon sequestration. It was demonstrated that SANGEA is a suitable estimation tool since the calculated total GHG emission showed 1% difference compared to Petrobras estimated value. Energy efficiency improvement is the main opportunity to reduce emissions. For the case study refinery future energy saving opportunities were described and their avoided emission estimation is 270,000 metric tonnes per year of CO2. On the other hand, new process units are required to comply with the gasoline and diesel stricter sulfur specifications, producing an additional emission of 208,000 metric tones per year of CO2. Thus, the successful energy saving efforts can be nullified by environmental requirements for fuel quality. This underlines the need for policy makers to strike a balance between new fuel requirements (with local impacts) and CO2 abatement policy (with global impacts)
Mestrado
Energia, Sociedade e Meio Ambiente
Mestre em Engenharia Mecânica

The control of particle emissions from an oil refinery is often difficult, due to changing operational conditions and the limited range of available treatment options. Excessive particle emissions have often been attributed start up problems with Fluidized Catalytic Cracker Units (FCCU) and little information is available regarding the exact composition and nature of these excessive emissions. Due to the complex nature of a FCCU, it has in the past been difficult to identify and control emissions, without the use of expensive end of pipe technologies. An Australian Oil Refinery, concerned with their catalyst emissions, sponsored this study of FCCU particle emissions. Due to the industrial nature of the project, a holistic approach to the management of emissions was taken, instead of a detailed investigation of a single issue. By looking at the broader range of issues, practical and useful outcomes can be achieved for the refinery. Initially, detailed emissions samplings were conducted to investigate the degree of particle emissions under start up conditions. Stack emissions were collected during a standard start up, and analysed to determine the particle size distribution and metal concentration of the emitted material. Three distinct stages of emissions were discovered, initially a high concentration of larger particles, followed by a peak in the very fine particles and finally a reduction of particle emissions to a more steady or normal operational state. The variation in particle emissions was caused by operational conditions, hardware design and catalyst characteristics. Fluctuations in the gas velocity through the system altered the ability of the cyclones to collect catalyst material. Also, the low bed level allowed air bypass to occur more readily, contributing to the increased emissions levels seen during the initial stage of the start up. Reduced fluidity characteristics of the circulating catalyst also affected the diplegs operations, altering the collection efficiency of the cyclone. During the loading of catalyst into the system, abraded material was quickly lost due to its particle size, contributing to fine particle emissions levels. More importantly, thermal fracturing of catalyst particles occurred when the cold catalyst was fed into the hot regenerator. Catalyst particles split causing the generation of large amounts of fine particle material, which is easily lost from the system. This loading of catalyst directly linked to the period of high concentration of fine particles in the emissions stream. It was found that metals, and in particular iron, calcium and silicon form a thick layer on the outside of the catalyst, with large irregular shaped metal ridges, forming along the surface of the particle. These ridges reduce the fluidity of the catalyst, leading to potential disruptions in the regenerator. In addition to this, the metal rich ridges are preferentially removed via attrition, causing metal rich material to be emitted into the atmosphere. To overcome these high particle emissions rates from the FCCU the refinery should only use calcinated catalyst to reduce the influence of thermal process and particle fracture and generation. Although the calcinated catalyst can fracture when added to the system, it is far less than that obtained with uncalicinated catalyst. To further reduce the risk of particle fracture due to thermal stresses the refinery should consider reducing the temperature gradients between the hot and cold catalyst. Due to the economics involved with the regenerator, possible pre-warming of catalyst before addition into system is the preferred option. This pre-heating of catalyst should also incorporate a controlled attrition stage to help remove the build up of metals on the surface of the particles whilst allowing this material to be collected before it can be released into the atmosphere. The remove of the metal crust will also improve the fluidity of the system and reduce the chance of catalyst blockages occurring. Finally, modelling of the system has shown that control of key parameters such as particle size and gas velocity are essential to the management of air emissions. The refinery should look at adjusting start up procedures to remove fluctuations in these key parameters. Also the refinery should be careful in using correlation found in the literature to predicted operational conditions in the system as these correlations are misleading when used under industrial situations.

Orientador: Antonio Carlos Zuffo
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: O aumento das intensidades de precipitação verificado nas últimas décadas tem solicitado mais os itens que compõem os sistemas de drenagem, mostrando a deficiência de alguns projetos de décadas passadas. Aliado a isto, a sociedade tem a necessidade premente de conservação dos recursos hídricos, por causa da escassez de água. Numa refinaria de petróleo este assunto é particularmente importante por causa dos grandes volumes de água utilizados e consumidos no processo industrial, assim como também por causa das grandes dimensões das áreas de processo e de estoque de matéria-prima e produtos acabados, que têm potenciais riscos ambientais associados (óleo cru, naftas, benzeno, "slop", enxofre). Quando a água precipita sobre estas áreas gera diferentes tipos de escoamentos, que podem ser simplesmente escoamento superficial livre (água pluvial), se livres de contaminação proveniente da área industrial, ou efluentes que devem ser tratados, caso venham a contaminar-se em sítios específicos dessas grandes áreas industriais. Neste trabalho pretende-se reunir os conceitos de hidrologia e de precipitações intensas, assim como os conceitos relacionados à produção do escoamento limpo ou efluente contaminado e aplicá-los aos elementos reais da Refinaria Presidente Bernardes (RPBC) em um Sistema de Informação Geográfica - SIG. Desta forma, constrói-se a análise-diagnóstico do problema considerando toda a dinâmica complexidade ambiental, econômica e legal que envolve a planta industrial na drenagem das suas águas.
Abstract: The increase on the rains intensity veryfied on last decades has requested the conveyances over than their capacity, showing deficiencies on old designed systems. At the same time, society has the crying need of water resources conservation, justified by the water's scarcity. In an oil refinery this subject is particularly important because of the great amounts of water that are used and consumed into the industrial process, and also because of the great dimensions of the process and stock of raw material and products areas, which has substances with great environmental risks associated (crude oil, naftas, benzene, slop, sulphur). When the water falls over these areas creates differentflows, that may become storm water flow, when free from the refinery contamination, or may become polluted effluents that must be treated, when contamined in specific industrial area sites. This work intends to join the concepts of hydrology and rain intensity, and also the concepts related to the clean and contamined discharge rate that are produced into the industrial plant and aply them to the Refinery Presidente Bernardes - Cubatão, into a Geographic Information System Database (GIS). By this way, it builds analysis-diagnosis of the problem considering the whole environmental, economics and legal complexity dynamics that involves the water drainage into the industrial plant.
Mestrado
Recursos Hidricos
Mestre em Engenharia Civil

The control of particle emissions from an oil refinery is often difficult, due to changing operational conditions and the limited range of available treatment options. Excessive particle emissions have often been attributed start up problems with Fluidized Catalytic Cracker Units (FCCU) and little information is available regarding the exact composition and nature of these excessive emissions. Due to the complex nature of a FCCU, it has in the past been difficult to identify and control emissions, without the use of expensive end of pipe technologies. An Australian Oil Refinery, concerned with their catalyst emissions, sponsored this study of FCCU particle emissions. Due to the industrial nature of the project, a holistic approach to the management of emissions was taken, instead of a detailed investigation of a single issue. By looking at the broader range of issues, practical and useful outcomes can be achieved for the refinery. Initially, detailed emissions samplings were conducted to investigate the degree of particle emissions under start up conditions. Stack emissions were collected during a standard start up, and analysed to determine the particle size distribution and metal concentration of the emitted material. Three distinct stages of emissions were discovered, initially a high concentration of larger particles, followed by a peak in the very fine particles and finally a reduction of particle emissions to a more steady or normal operational state. The variation in particle emissions was caused by operational conditions, hardware design and catalyst characteristics. Fluctuations in the gas velocity through the system altered the ability of the cyclones to collect catalyst material. Also, the low bed level allowed air bypass to occur more readily, contributing to the increased emissions levels seen during the initial stage of the start up. Reduced fluidity characteristics of the circulating catalyst also affected the diplegs operations, altering the collection efficiency of the cyclone. During the loading of catalyst into the system, abraded material was quickly lost due to its particle size, contributing to fine particle emissions levels. More importantly, thermal fracturing of catalyst particles occurred when the cold catalyst was fed into the hot regenerator. Catalyst particles split causing the generation of large amounts of fine particle material, which is easily lost from the system. This loading of catalyst directly linked to the period of high concentration of fine particles in the emissions stream. It was found that metals, and in particular iron, calcium and silicon form a thick layer on the outside of the catalyst, with large irregular shaped metal ridges, forming along the surface of the particle. These ridges reduce the fluidity of the catalyst, leading to potential disruptions in the regenerator. In addition to this, the metal rich ridges are preferentially removed via attrition, causing metal rich material to be emitted into the atmosphere. To overcome these high particle emissions rates from the FCCU the refinery should only use calcinated catalyst to reduce the influence of thermal process and particle fracture and generation. Although the calcinated catalyst can fracture when added to the system, it is far less than that obtained with uncalicinated catalyst. To further reduce the risk of particle fracture due to thermal stresses the refinery should consider reducing the temperature gradients between the hot and cold catalyst. Due to the economics involved with the regenerator, possible pre-warming of catalyst before addition into system is the preferred option. This pre-heating of catalyst should also incorporate a controlled attrition stage to help remove the build up of metals on the surface of the particles whilst allowing this material to be collected before it can be released into the atmosphere. The remove of the metal crust will also improve the fluidity of the system and reduce the chance of catalyst blockages occurring. Finally, modelling of the system has shown that control of key parameters such as particle size and gas velocity are essential to the management of air emissions. The refinery should look at adjusting start up procedures to remove fluctuations in these key parameters. Also the refinery should be careful in using correlation found in the literature to predicted operational conditions in the system as these correlations are misleading when used under industrial situations.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental Engineering
Faculty of Environmental Sciences
Full Text

Orientador: Valéria Maia Merzel
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Com o intuito de otimizar o consumo de água do meio ambiente, o reuso de efluentes têm sido cada vez mais empregado. Dentre as diferentes tecnologias utilizadas no tratamento de efluentes para reuso, os sistemas de osmose inversa se destacam por oferecer vantagens como: economia, alta produtividade e alta eficiência na remoção de sais. Entretanto, estes sistemas estão constantemente sujeitos à contaminação por micro-organismos, o que leva à perda da eficiência e aumento nos custos operacionais e de manutenção. Neste contexto, este trabalho tem por objetivo a caracterização da diversidade bacteriana de um sistema de membranas de osmose inversa que trata efluente de uma refinaria de petróleo, a fim de determinar quais são os micro-organismos relacionados com a formação de biofilme. A diversidade planctônica do sistema, i.e., água de alimentação, foi analisada através de plaqueamento e cultivo e de bibliotecas de genes RNA ribossomal 16S. A diversidade bacteriana associada às membranas foi analisada através de fingerprinting genético (DGGE ¿ Denaturing Gradient Gel Electrophoresis) e construção de bibliotecas de genes ribossomais 16S. A partir das amostras de água de alimentação, foram obtidos 37 isolados bacterianos e 211 clones. A análise das membranas foi realizada através do sequenciamento e identificação de 13 bandas excisadas a partir do fingerprinting genético, assim como pela construção de duas bibliotecas gênicas, com 73 e 57 clones cada uma. Dentre os gêneros encontrados nas diferentes amostras, os mais representativos e com potencial para formação inicial de biofilmes foram: Acidovorax, Bosea, Methylibium, Novosphingobium, Rhizobium, Shinella, Sphingomonas, Sphingobium, Devosia, Microbacterium e Sphingopyxis. De acordo com a literatura, alguns destes gêneros são constantemente encontrados em sistemas aquáticos e são importantes na formação inicial de biofilmes em sistemas de osmose inversa. O conhecimento da diversidade de micro-organismos presentes nestes sistemas fornece subsídios para entender a dinâmica e os mecanismos de formação de biofilmes na superfície de membranas, permitindo o o desenvolvimento de estratégias de controle e remoção mais específicas
Abstract: In order to reduce the environmental water consumption, reuse of wastewater has been increasingly employed. Among the different technologies used in the treatment of wastewater for reuse, reverse osmosis system stands out because of its advantages such as economy, high productivity and high efficiency in the removal of salts. However, these systems are constantly subjected to contamination by microorganisms, which causes loss of efficiency and increase in operating and maintenance costs. In this context, this study aims to characterize the bacterial diversity of a reverse osmosis membrane system treating effluent of an oil refinery in order to determine which are the microorganisms related to biofilm formation. The planktonic diversity of the system, i.e. feed water, was analyzed by cultivation techniques and 16S ribosomal gene clone libraries. Bacterial diversity associated with membranes was analyzed through genetic fingerprinting (DGGE - Denaturing Gradient Gel Electrophoresis) and the construction of 16S ribosomal gene libraries. Approximately 37 isolates and 211 clones were obtained from the feed water samples. Analysis of the membranes was performed by sequencing and identification of 13 excised bands from DGGE gel, as well as the construction of two 16S rRNA gene libraries. Among the genera found in the samples, the most representative and with potential to initial biofilm formation were Acidovorax, Bosea, Methylibium, Novosphingobium, Rhizobium, Shinella, Sphingomonas, Sphingobium, Devosia, Microbacterium and Sphingopyxis. According to the literature, some of these genera are constantly found in aquatic systems and are important in the initial formation of biofilms in reverse osmosis systems. Knowledge of the diversity of microorganisms in these systems provides subsidies to understand the dynamics and mechanisms of biofilm formation on the surface of membranes, allowing further development of control and more specific removal strategies
Mestrado
Genetica de Microorganismos
Mestra em Genética e Biologia Molecular

Thesis (MBA)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Business turnarounds usually involve drastic changes in an organisation. Change involves people and their emotions - positive and negative. Central to change stands a leadership team. Continuous change is a constant in the equation of competitiveness in today's economy. It is inevitable and definitely not an easy process, however, it becomes so much easier with the right people in the right positions together with a leader who mapped the route for the change vehicle. The right people do not need that much motivation to be inspired on the journey of implementing and sustaining change. This study concentrated mainly on the leadership skills observed during the change process at Callex Refinery, Cape Town. The author observed during the initiating and implementation stages of the change process that the leader did not build a coalition team, managers became less available and visible, face-to-face communication fell short of what was needed and a lack of feedback on performance resulted in mediocre performance. This resulted into lacklustre performances of the people. It is the responsibility of the leader to create a sense of urgency among his people. The leader continuously reminds his people where they are in relation to their vision; what is required to achieve the vision; how they will get there through trusting relationships, learning and development, teamwork and collaboration inside and outside the walls of the organisation. Great leaders create a climate of trust that is based on mutual respect and caring; the leader empowers his team in a caring environment. Mediocre results prevail in the absence of effective leadership. Effective leaders remind their people through communication why change is inevitable. They engage in dialogue, reflect, listen actively and lead by example whilst showing a sense of curiosity. Effective leaders grow new leaders. These leaders pay attention to what they will leave behind after they leave.
AFRIKAANSE OPSOMMING: Besigheidskentering gaan gewoonlik gepaard met drastiese veranderinge in 'n organisasie. Mense en hul emosies - positief of negatief - word gewoonlik by die veranderingsproses betrek. Midde in die verandering is 'n leierskapspan. Voortdurende verandering is 'n gegewe in vandag se mededingende ekonomie. Dit is onvermydelik en beslis nie 'n maklike proses nie, tog raak dlt makliker met die regte mense in die regte posisies saam met 'n leier wat die roetekaart opstel vir die veranderingstuig. Die regte mense het nie soveel motivering nodig om hul te inspireer op hul reis na die implementering en volhouing van verandering nie. Hierdie werkstuk konsentreer hoofsaaklik op die leierskap vermoë waargeneem gedurende die veranderingsproses by Caltex Raffinadery in Kaapstad. Die skrywer het gedurende die begin- en implementeringstadiums van die veranderingsproses opgelet dat die leier nie 'n koalisie span gebou het nie, bestuurders minder sigbaar geword het, van aangesig tot aangesig kommunikasie was nie wat dit moes wees nie en 'n gebrek aan terugvoer oor werkverrigting het uitgeloop op middelmatige werkverrigting. Dit het flou werkverrigting van werknemers tot gevolg gehad. Dit is die verantwoordelikheid van die leier om by sy mense 'n bewuswording van dringendheid te skep. Die leier moet voortdurend sy mense herinner aan waar hulle is in verhouding tot hul visie; wat verwag word om die visie te vol bring; hoe hulle daarby uit gaan kom deur vertrouensverhoudinge, leer en ontwikkeling, spanwerk en samewerking binne en buite die mure van die organisasie. Goeie leiers skep 'n klimaat van vertroue wat gebaseer is op respek en omgee: die leier bemagtig sy span in 'n sorgsame omgewing. Middelmatige resultate seëvier in die afwesigheid van effektiewe leierskap. Effektiewe leiers herinner mense deur kommunkiasie, hoekom verandering onvermydelik is. Hulle neem deel in tweesprake, reflekteer, luister aktief en lei deur hul voorbeeld terwyl hulle ook 'n mate van nuuskierigheid toon. Effektiewe leier kweek nuwe leiers. Hierdie leiers skenk aandag aan watter nalatenskap hulle gaan agterlaat as hulle self moet weggaan.

Petroleum refineries emit a variety of airborne substances which may be harmful to human health. HEIDI II (Health Effects Indicators Decision Index II) is a computer-based decision analysis tool which assesses airborne emissions from Canada's oil refineries for reduction, based on ordinal ranking of estimated health impacts. The model was designed by a project team within NERAM (Network for Environmental Risk Assessment and Management) and assembled with significant stakeholder consultation. HEIDI II is publicly available as a deterministic Excel-based tool which ranks 31 air pollutants based on predicted disease incidence or estimated DALYS (disability adjusted life years). The model includes calculations to account for average annual emissions, ambient concentrations, stack height, meteorology/dispersion, photodegradation, and the population distribution around each refinery. Different formulations of continuous dose-response functions were applied to nonthreshold-acting air toxics, threshold-acting air toxics, and nonthreshold-acting CACs (criteria air contaminants). An updated probabilistic version of HEIDI II was developed using Matlab code to account for parameter uncertainty and identify key leverage variables. Sensitivity analyses indicate that parameter uncertainty in the model variables for annual emissions and for concentration-response/toxicological slopes have the greatest leverage on predicted health impacts. Scenario analyses suggest that the geographic distribution of population density around a refinery site is an important predictor of total health impact. Several ranking metrics (predicted case incidence, simple DALY, and complex DALY) and ordinal ranking approaches (deterministic model, average from Monte Carlo simulation, test of stochastic dominance) were used to identify priority substances for reduction; the results were similar in each case. The predicted impacts of primary and secondary particulate matter (PM) consistently outweighed those of the air toxics. Nickel, PAH (polycyclic aromatic hydrocarbons), BTEX (benzene, toluene, ethylbenzene and xylene), sulphuric acid, and vanadium were consistently identified as priority air toxics at refineries where they were reported emissions. For many substances, the difference in rank order is indeterminate when parametric uncertainty and variability are considered.

This thesis examines how the balancing of economics, the market, individual participation and the environment is difficult in terms of trying to achieve emancipatory outcomes for all. There is no definite resolution, and none was expected for a topic such as this, as the outcomes are all compromises, but with possibilities for action through a pragmatic political system. Emancipation must be worked for in order to be reached and maintained via this pragmatism, with the hardest outcomes being that for the environment and participation by individuals. What is resolved, though, is that market liberalisation and strict regulation are not equitable solutions for the State to follow.

A common logistics problem in the petroleum industry is the scheduling of the pipeline transfer of petroleum fuels from oil refineries to distribution terminals. With a fixed set of pipelines, each with its own restrictions and constraints, the scheduler must organize the products and timing of transfers through each pipeline so as to deliver the required quantity of each product to the appropriate terminals to meet the demands of the market. Of the many possible approaches to the scheduling problem which are reviewed in this thesis one basic approach was chosen for future research. Specifically this thesis results from an investigation of the feasibility of using a tree-search algorithm based upon a similar approach successfully used in paper machine trim scheduling.

The stormwater basin at the Murphy Oil USA Inc petroleum refinery in Meraux, Louisiana contained approximately 6000-9000 cubic yards of oily sludge. Oily sludge of this type would be classified hazardous waste by the recently promulgated Toxicity Characteristic Leaching Procedure regulation (Federal Register, March 29, 1990). Land ban regulations (Federal Register, August 17, 1988) would prevent the land disposal of such waste A search of the literature showed that oil and grease and the specific land ban organics (benzene, toluene, ethylbenzene, xylene, naphthalene, phenanthrene, pyrene, anthracene, benzoanthracene, chrysene and benzopyrene) were aerobically biodegradable in landfarms and wastewater treatment systems. Literature also showed that the benzene, toluene, ethylbenzene and xylene would be partially volatilized The objective of the research was to perform a feasibility study to determine if the stormwater sludge was biodegradable and to follow up the feasibility study with a full scale operation to determine degradation rates of the land ban organics. A final objective was to determine if land ban standards could be met due to aerobic biodegradation A 100' x 120' x 9' reactor was built in the stormwater basin using two sheetpile walls. Six 20 hp aerators were used to mix and aerate the reactor. Mixed liquor samples were caught every other week and analyzed for levels of solids and organics. First order reaction rates were calculated for hydrocarbon oil and grease and the land ban organics Both the feasibility study and the full scale reactor operations demonstrated that the oil and grease and land ban organics were biodegradable. First order oil and grease degradation rates of 0.0135 - 0.0160 days$\sp{-1}$ were measured. Total BTEX levels in the sludge was decreased from 193.6 mg/kg to 1.3 mg/kg. Total polynuclear aromatic hydrocarbons were reduced from 2710 mg/kg to 0.62 mg/kg. Land ban standards were not met in the first phase, which operated at an average temperature of 77$\sp\circ$F, but were met in the second phase, which operated at an average temperature of 104$\sp\circ$F
acase@tulane.edu

Some oil refining companies have recently entered the field of exploration and production (E&P). Both the relatively high financial performances of E&P companies and the shrinking refining margin may motivate refiner’s decision to enter E&P. However, in making this decision, there are other factors to be considered. This study utilizes vertical integration and diversification theories to develop an integrated framework. This framework determines the factors which should be involved in a firm’s decision to enter another business area. In this theoretical approach and its application to Korean refining companies’ decision to enter into E&P, we discuss both the cost benefits and the advantages to acquiring strategic assets of the new business. As sources of short-term cost benefits, the paper discusses site specificity and regional performance. As long-term requirements, the paper explores the need to acquire E&P strategic assets. In early-stage decision making, the best mode may be a small equity investment in regional consortia. As a company acquires more and more strategic assets, it can decide to pursue global opportunities and/or to acquire an E&P company.
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