Dissertations / Theses on the topic 'Petroleum refineries'

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2012.
Electric motors consume over 60% of the world's generated electricity. In South Africa approximately 65% of the energy generated is consumed by electric motors (Niekerk, 2009). About 95% of motors in use in South Africa are Standard-Efficient Motors (SE-motors) that operate at an average efficiency of 84% to 90%, depending on the size of the motor and the load driven by them. High-Efficient motors (HE-motor) run at an efficiency of 2% to 8% higher than that of SE-motors. In recent years, a drive to replace SE-motors with HE-motors has been promoted for the purpose of Demand Side Management (DSM). The rationale of using HE-motors as a tool of DSM is to harness a small difference in operating efficiency per motor, which can result in a huge reduction in electricity consumption, depending on the number of HE-motors that will replace SE-motors. Reducing the demand for electricity is the key driving factor for DSM in South Africa, so as to relieve the already stressed power generation capacity. Other consequential factors of DSM are to reduce the amount of pollutant gases emitted into the atmosphere. To the electricity users DSM will be a great incentive, as reduced consumption of electricity will decrease the amount of money spent on electricity. Much has been written on the ability of HE-motors to reduce electricity consumption, cost of electricity and global pollution. ESKOM has even demonstrated the faith they have in these motors by giving rebates to motor users who are willing to exchange their existing SE-motors with new HE-motors. The rebates are paid by ESKOM through a newly established DSM program. However, it must be mentioned that savings through HE-motors is not a perfect guarantee. HE-motors have inherent design limitations that may inhibit the saving of energy. To achieve higher efficiency, HE-motors are designed to operate on a smaller slip that consequently increases their speed compared to that of SE-motors (Cheek et al., 1995). Higher rotor speed impacts energy saving abilities of HE-motors when they are used to drive fans, pumps and compressors, normally referred to as centrifugal loads. An increase in speed results in a proportional increase in flow. Power consumed by a motor goes up as a cube of the speed, and the flow rate increases linearly with speed. Motor loads in the petrochemical industry are generally centrifugal, and that is why this thesis focuses on refineries.

The study analyses the relative separation of the effects of changes in a nation's dollar exchange rate and crude oil's dollar price on a country's short-run crude oil derived demand. It examines the role of the dollar exchange rate on domestic and international petroleum flows and discusses the short-run inefficiencies that occur due to adjustment times in a country's domestic petroleum market. A four-equation, structural model of a country's short-run petroleum demand function for its two petroleum flows (crude oil and imported product) was used. Using the translog function, estimates of direct and indirect dollar exchange rate effects were estimated. To account for the role of a nation's refinery industry on international petroleum flows, a measure of the industry's flexibility was developed. The industry is said to be flexible when it can alter its inputs' naturally occurring product fractions to more closely meet the country's final demand. The index developed in this study measures the industry's increase in its output product slate's weighted average API, relative to the weighted average API of its crude oil and feedstocks inputs, adjusted for the crude oil's naturally occurring product fractions.

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.

Naphthenic acids (NAs) are carboxylic acids found in crude oil and petroleum products. The objectives of the research presented here were to: a) assess the occurrence and fate of NAs in crude oil and refinery wastewater streams; b) evaluate the biotransformation potential and inhibitory effects of NAs under nitrifying, denitrifying and methanogenic/fermentative conditions; c) investigate the factors affecting NA biotransformation under aerobic conditions and the microbes involved; and d) assess the toxicity of individual model NAs using quantitative structure-activity relationships (QSAR) and examine the effect of structure on NA biotransformation potential. NAs are ubiquitous in refinery wastewater streams and the desalter brine was found to be the main source of NAs in refinery wastewater. A commercial NA mixture was not biodegraded under nitrate-reducing or methanogenic/fermentative conditions. NAs were degraded under aerobic conditions by an NA-enriched culture; however, a residual fraction was not degraded under all conditions studied. The results indicated that NAs are not inherently recalcitrant and the residual fraction was due to the individual NA concentrations being below the minimum substrate concentrations at which they are no longer degraded. A fraction of the NA mixture was completely mineralized to carbon dioxide, with the remaining portion biotransformed to more oxidized intermediates. Overall, the results indicated that NAs were degraded under aerobic conditions; however, biological treatment of NA-bearing wastewater will not completely remove NA concentrations and thus, biological treatment must be combined with physical/chemical treatment to achieve complete NA removal.

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.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
As concentrações de arsênio em óleo cru podem variar de 10 a 30 mg kg-1. O selênio é encontrado em efluentes da indústria petrolífera, devido a sua presença no óleo cru, entre 0.03 - 1.4 mg.L-1 dependendo de sua origem geoquímica. Devido a semelhanças em suas propriedades químicas, o arsênio apresenta uma grande afinidade pelo enxofre, e comporta-se de modo similar ao selênio, seguindo o enxofre por toda a rota de refino do petróleo, localizando-se, principalmente, nos strippers de água ácida, local onde ocorre a separação/absorção do enxofre. Nesta fase do processo de refino, onde pode ocorrer a mais severa corrosão, estes ametais permanecem, provavelmente, imobilizados no fundo das torres podendo ser carreados à Unidade de Tratamento de Águas. Antes de serem lançadas ao meio ambiente, estas águas devem ser tratadas visando sua adequação a Legislação Brasileira (CONAMA, Res. 357/05). A eficiência de eliminação depende do processo empregado e está diretamente relacionada às espécies presentes nestas águas. A Cromatografia de Íons (CI) acoplada ao ICP-MS foi a escolha para o desenvolvimento deste trabalho - a especiação de arsênio e selênio em correntes aquosas do processo de refino. Foi alcançada uma boa resolução cromatográfica utilizando-se coluna de troca iônica e NaOH (0,1mol.L-1) como fase móvel e célula supressora para a minimização do sinal de fundo e de uma possível deposição de sais. Os Limites de Detecção alcançados para as espécies de arsênio foram de 0,15 e 0,18 (mi)g.L-1 para As (III) e As (V), respectivamente. Os Limites de Detecção para as espécies de selênio foram de 0,04, 0,05 e 0,05 (mi)g.L-1 para Se (IV), Se (VI) e SeCN, respectivamente, estes resultados estabelecidos empregando- se uma alça de amostragem de 100 (mi)L. O conteúdo total dos elementos estudados foi determinado por duas técnicas analíticas, ICPMS e GFAAS e a recuperação cromatográfica calculada por ambos os resultados. O método desenvolvido foi testado em três materiais de referência certificados, BCR 713, 714 e 715, tendo sido obtida uma concordância com os valores certificados. Ao final, a metodologia foi empregada em amostras de águas oriundas de diferentes etapas do processo de duas refinarias de petróleo. Todas amostras provenientes da saída das Estações de Esgoto Industrial (ETDI), apresentavam concentração de selênio e arsênio totais abaixo do limite estabelecido pela Legislação Brasileira. A metodologia proposta mostrou-se adequada para realização de análise de especiação de arsênio e selênio em matrizes complexas, como as existentes nas etapas de Craqueamento Catalítico e Unidades de Tratamento de Águas Residuais, assim como em amostra de interesse ambiental, como as da Estação de Tratamento de Efluentes Industriais. O método proposto mostrou-se adequado para a avaliação, monitoramento e melhor entendimento das transformações em unidades do processo de refino, assim como pode contribuir para uma adequação no tratamento de efluente.
The concentrations of arsenic in oil can vary of 10 the 30 mgkg-1. The selenium is found in effluent of the petroliferous industry, had its presence in the oil, between 0.03 -1,4 mg.L-1 depending on its geochemistry origin. For chemical reasons, arsenic shows a high affinity to sulfur, similar as selenium, thus following this element through the whole petroleum refining process, reaching the sour water strippers, where separation of sulfur from other inorganic species takes place. In this phase of the refining process, when it can occur the most severe corrosions, these ametais remain, probably, immobilized in the deep one of the towers being able to be carry out the Water Unit Treatment. Before launched to the environment, these waters must be treated aiming at its adequacy Brazilian Legislation (CONAMA, Res. 357/05). The elimination efficiency depends on the employed process and directly is related to the species gifts in these waters. The Ions Chromatography (CI) coupled to the ICP-MS was the choice for the development of this work - speciation of arsenic and selenium in stream watery of refining process. A good chromatographic resolution was reached using column of ionic exchange and NaOH (0,1mol.L- 1) as mobile phase and cell suppressor for the minimizes the signal from the background and a possible deposition lens and coins in ICPMS. The reached Limits of Detention for the species of arsenic had been 0,15 and 0,18 (mi)g.L-1 for As (III) and As (V), respectively. The Limits of Detention for the species of selenium had been of 0,04, 0,05 and 0,05 (mi)g.L-1 Se (IV), Se (VI) and SeCN, respectively, these established results using a loop of 100 (mi)L. The total content of the studied elements determined by two analytical techniques, ICPMS and GFAAS and the chromatographic recovery calculated by both results. The developed method was tested in three certified reference materials, BCR 713, 714 and 715, having been gotten an agreement with the certified values. Finally, the methodology was applied in the samples of different stages of the process of two oil refineries. All samples proceeding from effluent were below oft he limit established for the Brazilian Legislation. The methodology proposal revealed adequate for accomplishment, monitoring an speciation for arsenic and selenium in complex matrices, as existing in the stages of Fluid Catalytic Cracking and the Units of Treatment of Residual Water, as well as in an environmental samples.

The State of Kuwait has three large refineries, namely, Mina Al Ahmadi Refinery, Mina Abdullah Refinery and Shuaiba Refinery. These refineries process and refine Kuwait Crude Oil through different process units. There are many heaters, boilers and flares that form a part of the complicated equipment which enhance the different petroleum processes. Fuel gas is used as a firing fuel for those heaters and boilers. As a result, stack emissions like SO2, NOx, CO are predominantly present in the flue gases and this study focuses on those emissions and their impact on the surrounding residential area. The area of interest will be Umm Al-Hyman residential area. This study accumulates emission inventories from the three refineries and the respective ground level concentration of the pollutants in the neighboring residential area. It also focuses on the impact of emissions from the refinery operations on the ground level concentrations in the surrounding areas by using the inventory model and latest emission factors to provide accurate emission estimates. The models were developed and the results were verified with the actual data from the area of impact. As a result of the findings of the major pollutants, namely SO2, NOx & CO, it is found that SO2 and CO are not exceeding Kuwait EPA Ambient Air Quality Standards for Residential Areas normally. However, NOx is observed to exceed occasionally. Even though, NOx emissions from refineries sources represented by plume models were much less, there is a consistent increase in the measured NOx. Furthermore, in 2007, the measured hourly, daily and annual NOx concentration exceeded the international standard many times. The increasing trend in NOx is attributed to continuous increase in population and the number of motor vehicles. The study will go further step in recommending engineering solutions and best practices to reduce the pollutants concentrations which will help in the reduction of human health risks and protect the environment.

COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
De acordo com a legislação federal no Brasil (CONAMA: Res. 20/86, Art. 21), a concentração total máxima de selênio permissível em efluentes de fontes poluidoras deve ser tão baixa quanto 0,05 mg L-1. Em refinarias de óleo, nas quais óleo cru proveniente de xisto marinho selenífero é processado, os efluentes podem conter concentrações muito mais altas, exigindo a remoção deste elemento por processos de coagulação/precipitação. O comportamento de selênio nestes processos depende, criticamente, de sua forma química; selenocianato não é eficientemente removido por tratamentos convencionais de precipitação com uso de Fe(OH)3. O conhecimento sobre especiação de selênio no rejeito hídrico é portanto importante para o desenvolvimento de adequadas estratégias de tratamento. Neste trabalho, um novo método para análise de especiação de selenito (Se-IV), selenato (Se-VI) e selenocianato (SeCN-) é descrito, e são apresentados os primeiros resultados sobre a distribuição destas espécies em rejeitos hídricos oriundos de uma planta de refino de óleo brasileira. O método é baseado em separação das espécies por cromatografia de íons seguida por detecção em linha de 77Se, 78Se e 82Se usando ICPMS. O sistema cromatográfico empregado consiste de uma bomba HPLC equipada com válvula injetora manual e uma coluna de troca aniônica (Metrosep A Supp1); esta última interfaceada com o detector (ICPMS) utilizando nebulizador concêntrico-câmara ciclônica como sistema de introdução de amostra. Detecção condutimétrica e amperométrica das espécies de selênio foram também avaliadas, usando-se um cromatógrafo comercial de íons. Vários eluentes, já descritos na literatura para análise de especiação de selênio inorgânico, foram testados (carbonato/bicarbonato, tampão ftalato, ácido p-hidroxibenzóico, etc.) e permitiram, na maioria dos casos, uma boa separação entre Se(IV) e Se(VI), no entanto, resultaram todos em tempos de retenção muito longos e como conseqüência, alargamento do pico para o íon SeCN-1. Esta desvantagem foi eficientemente eliminada usando-se uma solução de ácido cianúrico (0,003 mol L-1), modificado com acetonitrila (2% v/v) e perclorato (0,002 mol/L) como fase móvel. Típicos tempos de retenção (s) para os três analitos aqui estudados foram: selenito (210), < selenato (250) e selenocianato (450). Repetitividades em posição de picos foram melhores que 1%, e na avaliação de área de pico melhores que 3 %. Limites de detecção (em ng) para as espécies usando o instrumento ELAN 5000 e uma alça de amostragem de 500-uL foram 0,04, 0,05 e 0,09, respectivamente. Não se dispunha de materiais de referência certificados para este estudo, contudo, resultados em efluentes de complexa composição e fortificados com os íons de interesse, mostraram aceitáveis recuperações (85% - 115%) e repetitividades (RSD < 5%), validando este método para o propósito previsto. Uma vez otimizado, o método foi aplicado a efluentes hídricos de uma refinaria de óleo. Em todas as amostras analisadas, selenocianato foi de longe a espécie mais abundante, atingindo concentrações de até 90 ug L-1, seguida por selenito. As concentrações de selenato estavam abaixo do limite de detecção em todas as amostras, explicável pelas características redutoras destas águas. As concentrações totais de selênio em todas as amostras, avaliadas por geração de hidretos (HG-ICPMS) e, alternativamente, por ICPOES, excederam aquelas obtidas pela análise de especiação, indicando a presença de outras espécies de selênio, não observadas pela metodologia aqui usada. Trabalhos estão em progresso para identificar e quantificar estas espécies.
According to federal laws in Brazil (CONAMA: Res. 20/86, Art. 21), the maximum permissible total concentration of selenium in effluents from polluting sources must be as low as 0,05 mg L-1. In oil refineries, in which crude oil from seleniferous marine shales are processed, wastewater may contain much higher concentrations, thus requiring removal of this element by coprecipitation/ coagulation procedures. The behavior of selenium in such processes depends critically on its chemical form; e.g. selenocyanate is not efficiently removed by the conventional treatment using Fe(OH)3 precipitation. Knowledge on the speciation of selenium in wastewater is therefore important for the development of adequate treatment strategies. In this work, a new method for the speciation analysis of selenite (Se-IV), selenate (Se-VI) e selenocyanate (SeCN-) is described and first results are presented on the distribution of these species in wastewater samples from a Brazilian oil refinery plant. The method is based on their ion chromatographic separation followed by on-line detection of 77Se, 78Se and 82Se using ICPMS. The chromatographic system employed consisted of HPLC pump equipped with a manual syringe loading injector, and an anion exchange column (Metrosep A Supp1, Metrohm); the latter interfaced with the ICPMS detector via a concentric nebulizer/cyclonic spray chamber sample introduction device. Suppressed conductivity detection and constant potential amperometric detection of these selenium species were also evaluated using a commercial IC-system. Several eluants, already described in the literature for the speciation analysis of inorganic selenium, were tested (e.g. carbonatehidrogencarbonate and phthalate buffer, p-hydroxy benzoic acid, etc) permitting in most cases a good separation of Se(IV) and Se(VI), however resulting all in very long residence times (>20min) and associated peak broadening for the polarizable SeCN - ion. This drawback could be effectively avoided using a solution of cyanuric acid (0.003 mol L-1), modified with acetonitrile (2% v/v) and perclorate (0.002 mol L-1), as the mobile phase. Typical residence times for the three analyte species here studied were: selenite (210 s) < selenate (250 s) < selenocyanate (450 s), with repeatabilities in peak position better than 1% and peak area evaluation better than 3 %. Limits of detection (in ng) for these species using an ELAN 5000 instrument and a 500-uL sample injection loop are 0.04, 0.05 and 0.09, respectively. No certified reference materials were available for this study, however, results on spiked effluent samples of complex composition showed acceptable recoveries (85% - 115%) and repeatibilities (RSD < 5 %), thus validating this method for its intended purpose. Once optimized, the method was applied to wastewater samples from a Brazilian oil refinery plant. In all samples so far analyzed, selenocyanate was by far the most abundant selenium species reaching concentrations of up to 90 uL-1, followed by selenite. Selenate concentrations were below the quantification limit in all samples, explainable by the reducing character of these waters. Total concentrations of selenium in most samples, assessed by hydride generation ICPMS and alternatively by ICPOES, exceeded those obtained from speciation analysis, indicating the presence of other selenium species, not observed by the here used methodology. Work is in progress to identify and quantify these species.

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 (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.

Thesis (MSc)--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: Landfarming is a widely used method for the disposal of contaminants in the petrochemical industry. It involves ploughing the contaminants into the top soil layer allowing biological breakdown. A historically landfarmed site was identified at a South African petrol refinery. The refinery used to dispose so-called American Petroleum Institute (API) -sludge onto a landfarming site. API-sludge consisted of a mixture of oil and water soluble contaminants originating from a process of separating refinery waste from reusable water and oil. Landfarming on this site was discontinued after excessive quantities of sludge were ploughed into the soil over time and it became obvious that effective biodegradation could not take place. An environmental assessment had to be carried out to assess to what extent the soil has recovered from the contamination and after remediation was done over time. Bioassays together with chemical analyses were executed to determine the level of pollutants in the soil and to assess the integrated effects of their bioavailable fractions. The landfarming site of the refinery was divided into two sections namely, a more contaminated north-site and less contaminated south-site. Soil samples were collected from both sites as well as from an off-site (control site). The soils were analysed physically, chemically and used in the bioassays. Two additional control soils were also used, OECD-soil and LUFA2.2 soil. Chemical analysis of the site soils showed the presence of heavy metals and high levels of diesel range organic hydrocarbons. The north-site had higher levels of contaminants compared to the south-site. Three species of soil organisms were used in standardised tests: Eisenia andrei, Enchytraeus doerjesi and Folsomia candida were exposed to the respective soils to study their survival, growth, reproduction success and avoidance behavior. Exposures to both site-soils were not acutely toxic to any organisms. F. candida had a decrease in juvenile production in both north- and south-site soils (289.42 ± 58.62 and 253.33 ± 122.94 respectively) compared to the control soil (479.89 ± 30.42). E. doerjesi showed an increase in produced juveniles exposed to north- and south-site soil (339.75 ± 76.92 and 414.00 ± 17.78 ) compared to control soil (57 ± 34.39). E. andrei had similar cocoon production when exposed to south-site soil than in off-site soil (19.00 ± 5.3 and 18.5 ± 9.7 respectively) but significantly less in north-site soil (1.25 ± 0.7). Only E. doerjesi showed avoidance of north-site soil. To determine the sensitivity of the organisms to the API-sludge, they were exposed to concentration series of API-sludge-spiked control soils. The effect concentrations were calculated as the concentration of API-sludge that will decrease the studied endpoints by 50% of the control soil (EC50). The EC50s varied for each species exposed in the different control soils showing that the toxicity of the API-sludge is to a certain extent dependent on the physical soil properties of the substrate. The reproduction of F. candida were most sensitive to the API-sludge in off-site soil (EC50 = 90 mg/kg) and the E. doerjesi the least sensitive in LUFA2.2 soil (EC50 = 36000 mg/kg). Five plant species were exposed to API-sludge-spiked potting soil and the germination success, early growth rate and biomass were studied. The plants were not as sensitive to API-sludge as the soil animals. Lettuce and grass were affected the most by API-sludge and beans were the most resilient species. With the addition of low levels API-sludge to the substrate, the growth rate of beans was stimulated. This study showed that the south-site has been successfully remediated and most soil organisms exposed to these soils were not affected by the levels of toxicants present. However, exposures to north-site soil still had negative effects on soil organisms. It is recommended that hydrocarbon contamination should be further remediated in the north-site soil before landfarming should be allowed to continue.
AFRIKAANSE OPSOMMING: Ploegverwerking is ‘n algemene remediëringsmetode vir die verwerking van afvalmateriaal in petrochemiese industrieë. Dit behels die inploeg van toksiese afvalmateriaal in die boonstegrondlaag sodat dit biologies afgebreek kan word. ‘n Voorbeeld van ‘n histories ploegverwerkte grondstuk is geidentifiseer by ‘n Suid-Afrikaanse olieraffinadery. Die raffinadery het in die verlede van die grondstuk gebruik gemaak om sogenaamde Amerikaanse Petroleum Instituut-slik (API-slik) daarin te ploeg. Die API-slik bestaan uit ‘n mengsel van olie- en wateroplosbare kontaminante afkomstig van die proses waardeur die raffinadery se afvalprodukte van hernubare water en olie geskei word. Nadat oormatige konsentrasies slik in die grond ingewerk is en bioremediasie nie meer doeltreffend kon voortgaan nie, is die ploegverwerking gestaak. ‘n Omgewingimpakstudie moes uitgevoer word om te bepaal tot watter mate die grond herstel het nadat remediasie oor tyd uitgevoer is. Toksisiteitstoetse en chemiese analises is uitgevoer om die vlakke van besoedeling sowel as die biobeskikbare fraksie daarvan in die grond te bepaal. Die ploegverwerkte area van die raffinadery is in twee verdeel naamlik, ‘n meer gekontamineerde noordelike area en ‘n minder gekontamineerde suidelike area. Grondmonsters is van die onderskeie areas asook van ‘n ongekontamineerde veld (as kontrole) naby die ploegverwerkte area versamel Die gronde is fisies- en chemies geanaliseer en toksisiteitstoetse is uitgevoer. Twee addisionele kontolegronde is ook tydens die blootstellings gebruik naamlik, OECD- en LUFA2.2-grond. Die chemiese analises van die ploegverwerkte toetsgronde het getoon dat daar steeds swaarmetale en hoë vlakke van dieselgekoppelde organiese koolwaterstowwe in die gronde teenwoordig is. Kontaminante was in hoër konsentrasies teenwoordig in die grond van die noordelike gebied as in dié van die suidelike gebied. Drie spesies van grondorganismes is gebruik tydens standaard toksisitetitstoetse. Eisenia andrei, Enchytraeus doerjesi en Folsomia candida is blootgestel aan die onderskeie toets- en kontrolegronde waarna hul oorlewing, groei, voortplantingsukses en vermydingsreaksies bestudeer is. Blootstellings aan die ploegverwerkte toetsgronde het geen akute toksisiteit vir enige van die spesies getoon nie. F. candida se juveniele produksie was laer in beide noordelike- en suidelike toetsgronde (289.42 ± 58.62 en 253.33 ± 122.94 onderskeidelik) as in die kontolegrond (479.89 ± 30.42). E. doerjesi blootstellings het ‘n toename in juveniele getalle getoon in die noordelike- en suidelike toetsgronde (339.75 ± 76.92 en 414.00 ± 17.78) in vergelyking met die ongekontamineerde kontolegrond (57 ± 34.39). Kokonproduksie by E. andrei was soorgelyk in die suidelike toetsgrond en ongekontamineerde kontrolegronde (19.00 ± 5.3 en 18.5 ± 9.7 onderskeidelik) maar beduidend minder as in noordelike toetsgrond (1.25 ± 0.7). Slegs E. doerjesi het ‘n beduidende vermydingsreaksie vir die noordelike toetsgronde getoon. Om die sensitiwiteit van die organismes aan vars API-slik te bestudeer, is hulle blootgestel aan konsentrasiereekse van API-slik in die onderskeie kontrolegronde. Die effektiewe konsentrasie (EK50) is bereken as die konsentrasie van API-slik wat die bestudeerde eindpunte met 50% sal verminder in vergelyking met die kontrolegrond Die EK50-waardes vir al die spesies het verskil na blootstelling aan die onderskeie kontrolegronde. Dus, die toksisiteit van die API-slik is tot ‘n sekere mate ook afhanklik van die fisiese grondeienskappe van die blootsellingssubstraat. Die voortplanting van F. candida was die gevoeligste eindpunt vir die blootstelling aan API-slik in kontolegrond (EK50 = 90 mg/kg) en E. doerjesi was die minste gevoelig in LUFA2.2 grond (EK50 = 36000 mg/kg). Vyf plantspesies is ook blootgestel aan API-slikgekontamineerde potgrond en die saadontkiemingssukses, vroeë groeikoers en biomassa is bestudeer. Alhoewel plante nie so sensitief was vir die API-slik soos die gronddiere nie, was blaarslaai en gras die meeste geaffekteer tydens die blootstellings. Boontjies was die ongevoeligste en met die toevoeging van lae konsentrasies API-slik (2.5% API-slik), is hul groeikoers selfs gestimuleer. Uit die studie was dit duidelik dat die suidelike deel van die grondstuk meer suksesvol as die noordelike geremidieer is en dat meeste grondorganismes wat daaraan bloot gestel is nie geaffekteer is deur die vlakke van kontaminasie wat steeds teenwoordig is in die grond nie. Die toetsgronde uit die noordelike deel het egter steeds negatiewe effekte op die grondorganismes gehad. Dit word voorgestel dat die koolwaterstof kontaminasie verder geremidieër behoort te word in die noordelike deel van die grondstuk voordat verdere ploegverwerking van die afval daar gedoen word.

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.

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: During the last 30 years I have been involved in the theory and practice of thermal engineering and in particular, in the areas of air-cooled heat exchangers and cooling towers for the power, refrigeration, process and petrochemical industries in South Africa and internationally. During this period, I have authored and co-authored more than 120 papers that were published in technical journals or presented at conferences nationally or internationally. Most of these papers are included in a manuscript entitled "Air-cooled Heat Exchangers and Cooling Towers", in which Ipresent a systematic approach to the thermal performance evaluation and design of industrial air-cooled heat exchangers and cooling towers. This original publication also includes the relevant practice applicable to the design of cooling systems, based on my experience as a consultant to industry. Design offices throughout the world presently follow our design methods, or at least employ many of our research results. Our work has furthermore contributed to the development of improved cooling system designs (e.g. new dephlegmator header designs), components (e.g. single-row flattened finned tubes) and product improvement and quality control (e.g. performance testing and measurement of thermal contact resistance between fin and tube during production). Many of our research findings have found application in the modification of existing cooling systems. The manuscript has also been used as reference work during the presentation of short courses to practising engineers and consultants in industry and to engineering graduates at the University of Stellenbosch. A two-volume edition of this manuscript was published by PennWell Corp., Tulsa, Oklahoma, USA in 2004.
AFRIKAANSE OPSOMMING: Gedurende die laaste 30 jaar was ek betrokke by die teorie en praktyk van lugverkoelde warmteoordraers en koeltorings vir die kragopwekkings-, verkoelings-, proses- en petro-chemiesenywerhede in Suid-Afrika sowel as in die buiteland. Gedurende hierdie periode was ek outeur en mede-outeur van meer as 120 publikasies wat in tegniese tydskrifte, of by plaaslike of oorsese konferensies aangebied is. Die meeste van hierdie publikasies vorm deel van 'n manuskrip getiteld "Air-cooled Heat Exchangers and Cooling Towers" waarin ek 'n sistematiese benadering tot die bepaling van die termiese vermoë en ontwerp van industriële lugverkoelde warmteoordraers en koeltorings aanbied. Hierdie oorspronklike publikasie bevat ook die relevante praktyk wat van toepassing is op verkoelingsaanlegte. Ontwerpkantore wêreldwyd volg tans hierdie ontwerpsmetodes, of gebruik ten minste baie van ons navorsingsresultate. Ons werk het verder bygedra tot die ontwikkeling van verbeterde verkoelingsaanlegte (bv. nuwe deflegmatore), komponente (bv. enkelbuisry platvinbuise ) en verbeterde produkte en kwaliteitskontrole (bv. toetsing van verkoelingsvermoë oftermiese kontakweerstand tussen vin en buis gedurende produksie). Baie van ons bevindinge het toepassing gevind in die modifikasie van verkoelingsaanlegte. Die manuskrip is ook as verwysing gebruik gedurende die aanbieding van kort kursusse aan ingenieurs in die praktyk en aan nagraadse studente aan die Universiteit van Stellenbosch. 'n Twee-volume uitgawe van die manuskrip is deur PennWell Corp., Tulsa, Oklahome, VSA in 2004 gepubliseer.

Orientador: Antonio Carlos Bannwart
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Este estudo teve como objetivo a análise de processos industriais, os mais abrangentes possíveis, visando sua otimização do ponto de vista energético-econômico. Neste intento, buscou-se apresentar não apenas um único ponto de otimalidade, mas um conjunto de opções que permita a um decisor escolher a situação mais conveniente. No desenvolvimento deste estudo foram utilizados um conjunto de Métodos de Otimização, dentre os quais podem ser destacados a Metodologia Pinch de Recuperação de Energia, baseada em uma redistribuição de potenciais térmicos dentro do processo analisado, e os Métodos originários da Programação Matemática, em especial a Programação Linear. Analisou-se em profundidade o caso, relativo à lndúsrtria de refino de Petróleo, de uma etapa de Craqueamento Catalítico da Refinaria de Paulínia, da PETROBRÁS. Entretanto, o conjunto de procedimentos aplicados neste trabalho mostrou-se eficiente quando da análise de outros segmentos industriais, em particular das lndústrias Química, de Alimentos e Petroquímica, como apresentado no decorrer deste trabalho. Este estudo mostra que é perfeitamente possível fazer-se uma análise energética e uma avaliação econômica de sua implantação, de uma maneira muito satisfatória e rápida
Abstract: This work deals with the industrial process analysis, includingvarious types and sizes, looking for their optimization fiom the economic and energetic point of view. Not only a single point of optimality was searched but a set of options which could permit to a decision maker to choose the best situation in each case. ln the development of this study were utilized a set of Optimization Methods, among which it can be mentioned the "Pinch Point Methodology" to heat recovery in networks, which is based in a redistribution of the thermal potentials of the process analyzed, and the methods originated tfom the Mathematics Programming, in special the Linear Programming. A deep analysiswas made on the case relative to an oil refinery.More precisely a part ofthe catalytic cracking of the Paulinia's Oil Refinery of PETROBRAS. The set of procedures applied in this work, it can be shown efficient when the analysis is applied to other industrial branches, in particular in the Chemistry, Food and Petrochemistry industries, as shown in throughout this work. This study shows that is possible to make an energetic analysis and an economic cost evaluation on the implementationof a process, in a fast and sactisfatory manner
Doutorado
Termica e Fluidos
Doutor em Engenharia Mecânica

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

Durante muitos anos tem-se usado a técnica de programação linear (Linear programming- LP) para abordar o problema do planejamento da produção em refinarias de petróleo. Esta técnica é baseada na linearização do comportamento não linear dos processos num conjunto particular de condições operacionais. Contudo, modelos lineares não são uma boa representação da operação dos processos de refino, pois estes envolvem diferentes operações físicas (separação de fases, mistura de correntes intermediárias, etc.) e químicas (reações de craqueamento, reações de hidrotratamento, etc.) caracterizadas pelo seu comportamento não linear. Como conseqüência, os resultados (plano de operação) de modelos de planejamento da produção baseados na técnica de programação linear são de difícil implementação na operação. Por outro lado, recentes avanços na capacidade de cálculo dos computadores, assim como nas ferramentas matemáticas (algoritmos de otimização) utilizadas para solucionar os modelos de planejamento da produção, permitem a implementação de modelos não lineares de processos em modelos de planejamento da produção. Este trabalho é focado na formulação de modelos de processos adequados (boa aproximação da operação e baixo custo computacional) para o planejamento da produção em refinarias de petróleo. Inicialmente, é abordada a formulação de um modelo empírico para unidade de destilação o qual foi validado com sucesso usando um simulador rigoroso de processos. A seguir, um modelo empírico para uma unidade de craqueamento catalítico fluidizado (FCC) foi gerado e validado a partir de dados obtidos num simulador rigoroso de processo da PETROBRAS. Estes modelos empíricos superam as limitações dos modelos lineares e não lineares para unidades de destilação e unidades de FCC previamente propostos por outros autores. Em seguida, os modelos empíricos desenvolvidos foram implementados no planejamento da produção (para um único período) de duas refinarias: uma de pequena escala (só duas unidades de processo) e uma de média escala (com 7 unidades de processo). Os modelos de planejamento resultaram em dois problemas de programação não linear que foram resolvidos usando três solvers (CONOPT 3, IPOPT e MINOS) disponíveis na plataforma computacional GAMS (General Algebraic Modeling System). Os modelos de planejamento da produção foram resolvidos com sucesso num tempo computacional inferior a um segundo (CPU time < 1 s) pelos solvers.
For many years production planning problems in the petroleum refineries have been addressed using the linear programming (LP) technique. This technique is based on linear process models (linearization of nonlinear process behavior at a particular set of operating conditions). Nevertheless, the linear process models are not suitable for refinery process modeling, since refinery processes involve both physical (phase separations, blending operations, etc.) and chemical operations (cracking reactions, hydrotreating reactions, etc.) that are characterized by their nonlinear nature. Due to this fact, the results (operating plans) from production planning models based on the linear programming technique are operationally not reliable. On the other hand, recent advances in the computer hardware and in the mathematical tools (optimization algorithms) used for the solution of production planning problems, allow the implementation of nonlinear process models in the production planning models. This work deals with the formulation of non linear empirical process models for petroleum refinery planning. Firstly, the formulation of non linear empirical process model for refinery process is addressed. Two processes were studied: distillation and fluid catalytic cracking (FCC). An empirical model for crude distillation units was developed and successfully validated using rigorous simulations carried out in HYSYS® and the empirical model for a FCC unit was developed and successfully validated using a rigorous FCC simulator from PETROBRAS. These empirical models overcome the limitations of both linear and nonlinear empirical models for crude distillation and FCC units previously developed by others authors. Subsequently, the empirical models developed in this work were successfully implemented in the production planning model for two refineries: a small scale refinery (with two process units) and a medium scale refinery (with 7 process units). The production planning models resulted in two nonlinear programming problems that were solved using three different solvers (CONOPT 3, IPOPT and MINOS) available in GAMS (General Algebraic Modeling System) platform. The computational time for the solution of the production planning models were less than 1 second (CPU time < 1 s).

Thesis (MBA)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: South Africa's main requirements for power are in the form of electricity and liquid fuels The country's electricity is generated mainly from coal while the liquid fuels requirement is mainly from crude oil. Both coal and crude oil use are coming under increasing pressure locally because of pollution and accompanying environmental awareness. Internationally both energy sources are also increasingly being abandoned as preferred energy sources, in first world countries, in favour of cleaner energy sources.ln view of these developments in the macro environment South Africa's gas to liquids refinery built in the early 1990's seems a well placed past investment ahead of its time. This study project looks at the economic feasibility of the continued existence of the PetroSA gas to liquid plant in Mossel Bay.The study looks at South Africa as well as Southern Africa's energy resources , the effect of changing legislation on the future use of energy resources and the economics of the Mossel Bay facility. The study finds that South Africa's abundance of coal reserves, its lack of oil and gas reserves and the slow pace of environmental legislation delivery means that gas is unlikely to become a major source of energy in South Africa.The Mossel Bay gas to liquids plant is profitable but its high fixed costs and certain growth of this cost component means that the continued feasibility of operations is dependant on favourable movements in the exchange rate and oil price. To answer the question about whether to continue operating or close down the analysis found that although although early closure would provide a return of more than 15 percent it would be even more viable financially to make an investment for more gas and continue operations.The main reason for the better than average projected returns is the high oil price .The decision to close down the Mossel Bay plant is not likely to be based on financial considerations alone. The recommendation is thus to continue operations untill 2016.The investment required to secure more gas would , even in the worst case scenario, provide a satisfactory return on investment.
AFRIKAANSE OPSOMMING: Suid Afrika se energie behoeftes is hoofsaaklik vir elektrisiteit en brandstof. Die meerderheid van die land se elektristeit word deur middel van steenkool opgewek terwyl ru-olie gebruik word om brandstof te vervaardig. Beide steenkool en ru-olie word al hoe meer onder druk geplaas as gevolg van besoedeling en 'n meer omgewing bewuste publiek. Op internasionale vlak , in eerste wereld lande word die gebruik van steenkool en ru-olie al hoe meer afgeskaf ten gunsle van skoner kragbronne. In die lig van hierdie verwikkeling in die makro omgewing mag dit op die oog af Iyk of PetroSA se gas na vloeistof aanleg in Mosselbaai, wat reeds in die vroee 1990's gebou is, as 'n goeie destydse strategiese belegging voorkom. Hierdie studie projek ondersoek die ekonomiese lewensvatbaarheid van die voorgesette bestaan van die PetroSA se Mosselbaai gas na vloeislof aanleg. Die studie kyk na Suid-Afrika sowel as die groter Suider Afrika se natuurlike energiebronne, die invloed van verandering in wetgewing op die toekomstige gebruik van energiebronne en die ekonomiese kenmerke van die aanleg in Mosselbaai. Die bevinding van die studie is dat Suid-Afrika se oorvloed van steenkool, sy tekort aan natuurlike gas en die stadige pas waarteen omgewings-wetgewing ontwikkel word, daartoe lei dat gas nie 'n volmatige energiebron in Suid Afrika sal word nie. Die aanleg in Mosselbaai is huidiglik winsgewind maar sy hoe vastekoste en groei hiervan belemmer sy vooruitsigte vanuit 'n finansiele oogpunt. Die winsgewindheid van die aanleg is afhanklik van 'n verswakkende Suid Afrikaanse geldeenheid en verhogende ru-olie pryse. Die vraag onstaan dus of die aanleg moet toemaak en of produksie moet voortgaan. Die ondersoek vind dat alhoewel die sluiting van die aanleg 'n opbrengs van meer as 15 persent sal lewer dit selfs meer finansieel aantreklik is on te belê in meer gas sodat produksie kan voortgaan. Die hoofrede vir die bogemiddelde opbrengs is die hoe oilieprys. Dit is onwaarskynlik dat die oorweging om die Mosselbaaise aanleg sluit suiwer op finansieele oorwegings sal rus. Die aanbeveling is dus om voort te gaan met produksie tot 2016. Die belegging wat nodig is vir meer gas sal selfs onder die mees pessimistiese omstandighede steeds 'n bevredigende opbrengs lewer.

Orientador: Rubens Maciel Filho
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: Esta tese apresenta um estudo de estratégias de esquemas de controle em unidades de destilação a vácuo de refinarias de petróleo, com o uso de dados e informações de uma refinaria brasileira, de modo a se desenvolver uma simulação representativa do processo, onde uma diferença global máxima de 5% entre os resultados de simulação e os dados de saída reais foi obtida. A simulação foi executada com alto nível de detalhamento, com cálculos de queda de pressão, dimensionamento de sistemas de bombeamento e uso de internos de coluna comerciais. Uma análise paramétrica foi executada para a verificação das variáveis mais influentes do processo. A simulação em estado estacionário resultante foi então convertida para o regime dinâmico, onde um esquema de controle equivalente ao esquema de controle da planta real foi implementado. Este esquema de controle foi submetido a um conjunto de perturbações usuais ao processo real, produzindo respostas dinâmicas do processo para cada perturbação aplicada. Pela análise das dinâmicas destas respostas e das respostas do sistema em malha aberta, um esquema de controle alternativo foi proposto e verificado da mesma maneira que o esquema de controle equivalente. Malhas de controle específicas para quantificar a qualidade dos produtos, tendo por base o índice ASTM D86 foram inseridas. A comparação entre os dois esquemas de controle por meio das respostas dinâmicas na qualidade dos produtos, considerando como parâmetro o ISE (Integral Squared Error) das malhas de cada esquema para comparação, apresentou uma redução média do erro em 70% na qualidade dos produtos principais
Abstract: A petroleum vacuum distillation unit study on control scheme strategies is developed in this work. Real plant data and information is gathered from a Brazilian Refinery to develop a representative simulation of the process, which had achieved a maximum 5% overall difference from the plant results. The simulation was set to be highly detailed, including pressure drop calculations, pumping system and the use of commercial column internals (packing and plates) in it. A parametric analysis was carried in order to verify the most influent variables in the process, with respect to temperature profiles, product flows and product qualities. The resultant steady state simulation was then converted into dynamic regime, when a control scheme equivalent to the real plant control scheme was implemented. This control scheme was then subjected to a set of common perturbations that occur in the real process, producing the dynamic response of the process to each perturbation applied. By analyzing the dynamics of these responses and the open loop responses, an alternative control scheme is proposed and verified in the same manner the later one was. A specific control loop was proposed to account a petroleum product quality index, such as ASTM D86 95% recovery. The comparison of the control schemes by means of the dynamic responses considering the correlated ISE (integral squared error) of each scheme has shown an average error reduction of 70% in the main products quality
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química

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 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

博士
國立成功大學
化學工程學系碩博士班
96
The scope of this study is concerned with the petroleum supply network operated by a typical oil company, in which the crude oil is consumed to produce ethylene, propylene, liquefied petroleum gas, butadiene, benzene, toluene, xylene, gasoline, kerosene, diesel and other by-products. These petrochemical products are usually manufactured with a cluster of strategically-located conversion refineries. A complete petroleum supply chain consists of at least 13 different types of production units, i.e., the atmospheric distillation units, the vacuum distillation units, the cokers, the fluid catalystic cracking units, the naphtha crackers, the butadiene extraction units, the hydrotreaters, the aromatics extraction units, the reforming units, the xylene fractionation units, the parex units, the xylene isomar units, and the tatoray units. Traditionally, the production plan of an industrial supply chain is created first and a compatible schedule is then identified accordingly. Since the detailed scheduling constraints are often ignored in the planning model, there is no guarantee that an operable schedule can be obtained with this hierarchical approach. To address this issue, a single mixed-integer linear program (MILP) has been formulated in this study to coordinate various planning and scheduling decisions simultaneously for optimizing the supply chain performance. Solving this MILP model yields the proper procurement scheme for crude oils, the schedules for producing various petrochemical products, and the corresponding logistics. The appropriate sources (suppliers) of raw materials, the economic order quantities, the best purchasing intervals, and also the transportation schedules can be identified accordingly. In particular, the optimal production schedule of olefins, aromatics and other petrochemical products over the specified planning horizon is configured by selecting throughput, operating conditions and technology option for each unit in the chain, by maintaining the desired inventory level for each process material, by securing enough feedstock, and by delivering appropriate amounts of products to the customers. On the basis of the above-mentioned basic MILP model, two modified versions have been developed for specific applications. A deterministic planning model has been constructed for the supply chains of light aromatic compounds, i.e., benzene, toluene, o-xylene and p-xylene. From the optimal solutions, it is clear that the proposed approach can be used not only to generate the most economic production plan on the basis of given supply and demand rates, but also select the best process configuration in a multi-train supply chain. On the other hand, a stochastic programming (SP) model has also been formulated according to the basic model to synthesize the optimal planning strategy of petroleum supply chain under uncertain supplies and demands. The uncertain parameters in this model include: the supply rates of raw materials (i.e., petroleum), intermediate oils (i.e., heavy naphthas, light naphthas and mixed xylenes) and consumer products (i.e., liquefied petroleum gas, diesel, kerosene and gasoline), and the demand rates of the aforementioned consumer products. By solving the SP model, the best production and transportation strategies can be determined for every possible scenario.

碩士
國立成功大學
化學工程學系碩博士班
101
Integration of hydrogen resources has always been a popular cost-reduction measure in the petroleum refining industry. A mixed-integer nonlinear programming model will be developed for generating the cost-optimal hydrogen network designs according to the pressures, flow rates and hydrogen concentrations of the inlet and/or outlet streams of various hydrogen producers and consumers. Although existing models could also be used to produce low-cost designs, it should be noted that only the compressors and pressure swing adsorption (PSA) columns were considered in the previous studies. To account for the current trends of stricter environmental regulations, the hydrogen resources must be integrated properly to achieve two distinct objectives, i.e., minimum total annual cost (TAC) and minimum CO2 emission rate. For this purpose, the mathematical models of additional units, i.e., fuel cells and steam reforming plants (for producing H2), will be added in the mathematical programs. The trade-off issues between the economic and environmental incentives will then be handled by establishing the Pareto front of the aforementioned multi-objective optimization problem. Finally, realistic case studies will be carried out to confirm the feasibility and effectiveness of the proposed approach.

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.

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.