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Impact des minéraux sodium et phosphore sur les propriétés de catalyseurs Cu/FER dédiés à la réduction sélective des oxydes d'azote par l'ammoniac / Impact of sodium and phosphorous on the properties of Cu/FER for the selective catalytic reduction of nitric oxides by ammoniaTarot, Marie-Laure 04 May 2018 (has links)
Afin de limiter les rejets de polluants dans l’atmosphère par les véhicules, les normes Euro ont été mises en place en Europe à partir des années 1990. Ces normes sont de plus en plus strictes. Par exemple, pour les cas des poids lourds, le maximum d’émission des NOx a été divisé par cinq lors du passage Euro V (2009) à Euro VI (2014). Parallèlement à cela, certaines flottes captives de poids lourds roulent au 100 % biodiesel. Or, ce carburant contient des minéraux (Na, K, P) qui peuvent interagir avec la ligne de dépollution des gaz d’échappement.Dans ces travaux, l’étude a porté sur l’impact de Na et P déposés séparément ou simultanément sur des catalyseurs de réduction catalytique sélective des oxydes d’azote par l’ammoniac (NH3-SCR) à base de zéolithe Ferrierite (FER) contenant du cuivre.En mettant en relation les activités catalytiques en NH3-SCR et les différentes caractérisations mises en œuvre avant et après ajout des minéraux, il a été conclu que l’ajout de sodium entrainait une perte d’activité à basse température (< 300 °C) liée à l’empoisonnement des sites acides du catalyseur, et que la perte d’activité à haute température (> 450 °C) est liée à la formation de CuO. Cette formation de CuO est due à un échange entre le cuivre et le sodium lors de l’empoisonnement par voie aqueuse. Pour l’empoisonnement au phosphore, la désactivation à basse température (< 300 °C) apparait liée à une interaction entre le cuivre et le phosphore. Cette interaction entraine une augmentation de la température de réduction du cuivre. L’ajout simultané de sodium et phosphore entraine une désactivation des catalyseurs plutôt similaire à celle du phosphore qu’à celle du sodium. / In order to decrease the air pollution due to vehicles, European legislation have been implemented since the 90’s. The European norm are stricter. For example, the NOx emissions limit for trucks were divided by five between Euro V (2009) and Euro VI (2014). In parallel, some trucks use exclusively 100 % biodiesel. Unfortunately, biodiesel contains some minerals (Na, K, P) with can interact with the exhaust gas post-treatment system.This work presents the impact of Na and/or P deposits on Selective Catalytic Reduction catalysts with dedicated to the NH3-SCR process, based on copper/Ferrierite (FER).By combining the results of NH3-SCR catalytic activity and characterisations before and after adding minerals, the main parameters of deactivation were highlighted. Sodium deactivation at low temperature (< 300 °C) is due to the decrease of acidity. The deactivation at high temperature (> 450 °C) is due to the formation of copper oxide when sodium was added in water. This formation of CuO results of an exchange of Na and Cu in the exchange positions of the zeolite. Phosphorous addition mainly leads to a catalytic deactivation at low temperature (< 300 °C), the deactivation seems to be link to Cu-P interaction. This interaction leads to the increase of the reduction temperature of copper. Overall, the simultaneous addition of sodium and phosphorous leads to a decrease of catalytic activity similar to the one with phosphorous alone.
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Zneškodňování spalin znečištěných NOx / Treatment of flue gas polluted by NOxHanák, Libor January 2009 (has links)
There is an overview of secondary methods for NOX removal from stationary sources in the first part of master’s thesis. There are well known methods as SCR o SNCR, but also new and experimental ones. An accent is putting on catalytic filtration, especially on cloth filter, which will be used for experiments. An important part of master’s thesis is a project of new experimental unit for experiments with cloth and ceramic catalytic filters as well as with a bit of cloth filtration material. Unit has compact proportions, high-class measurement and control and wide application spectra. Other advantages of this equipment are fast and easy cleaning and installation. This unit, called INTEQ II, can be used in plants or in laboratories. There is prediction model created together with new technology. It enables calculation of efficiency at catalytic filters with variable conditions without many experiments. This model is elaborate and will be finished with dates from measuring. There in only summary of planned experiments in this thesis, because measurements at new unit have not done yet. Experiences with operations at unit INTEQ I were used for proposal of new equipment and for experiments planning.
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Redukce NOx obsažených ve spalinách / Reduction of NOx contained in flue gasJaník, Prokop January 2012 (has links)
Research in the field of NOX abatement has grown significantly in the past two decades. The general trend has been to develop new catalysts with complex materials in order to meet the stringent environmental regulations. The master’s thesis deals with the cleaning flue gases through a filter element which is from porous ceramics. There is catalyst implemented for NOx reduction throug the method of selective catalytic reduction in the filter element. There is also description of experimental unit for flue gas cleaning. Part of the thesis is creation of prediction model which allows to predict efficiency reduction in the filtration device operating conditions with some accuracy.
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MECHANISMS OF CALCIUM-MEDIATED ARRHYTHMOGENESIS IN HEART FAILUREHoeker, Gregory Scott January 2008 (has links)
No description available.
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Identifying risks of AdBlue spray on stainless steel surfaces / Identifiering av risker med AdBlue-spray på rostfria stålytorTvinne Flyg, Evelina January 2021 (has links)
Utsläppskontroll, reglerad av allt strängare lagstiftning, ställer höga krav på utvecklingen av noggranna efterbehandlingssystem för avgaser. När det gäller utsläpp från dieselmotorer utgör NOx-minskning en av de största utmaningarna. För tunga fordon tacklas denna utmaning ofta genom ett SCR-system. SCR-systemet kan omvandla upp till 95% av NOx-utsläppen till kväve och syre, genom utnyttjande av ett selektivt reduktionsmedel över en katalysatoryta. Ammoniak är ett sådant reduktionsmedel men är inte i sig ett lämpligt val för mobila tillämpningar på grund av de miljö-, hälso- och säkerhetsproblem som är förknippade med denna förening. Istället används en ofarlig vattenlösning med urea, kallad AdBlue, som vid injektion i varm avgas sönderdelas till tillräckliga mängder ammoniak som behövs vid SCR-katalysatorn för att minska den NOx som produceras relativt motorns belastningspunkt. AdBlue-injektion i avgasströmmen kan emellertid komplicera ett redan komplext system ur ett materialvalsperspektiv. Även om urea inte anses vara ett särskilt korrosivt ämne råder en viss osäkerhet kring biprodukterna som kan bildas vid ofullständig nedbrytning av urea. I avgassystem nämns ofta dessa ureaderivat i samband med ett fenomen då smält urea skapar en flytande film på avgassystemets ytor som då genererar fasta biproduktavslagringar vid filmens yttre kanter. Denna studie syftar till att identifiera några av riskerna kopplade till AdBlue-injektion på ytor av rostfritt stål. Därav undersöks nedbrytningsbeteendet hos de austenitiska rostfria stålen 1.4828 och 1.4835 efter vätning med AdBlue-spray under statiska förhållanden i avgaser, 350 ℃ och 700 kg/h. Testbänksproceduren ger ett kostnadseffektivt sätt att sålla ut potentiella rostfria stål i en realistisk avgasmiljö innan komponenttestning. Testet av 1.4828 inkluderar även ett dragprov, för att undersöka betydelsen av plastiska deformationer. Därtill undersöks en martensitisk stålkomponent, som tidigare använts i en avgasmiljö under AdBlue-injektion, för att ytterligare bilda en uppfattning om de risker som ett material under dessa förhållanden måste uthärda. Rostfria stål undersöktes efter exponering med konfokalmikroskopi och SEM/EDS. Avlagringar som hittades på 1.4835 studerades med FTIR. Resultaten visar riskerna med ett dåligt materialval och eventuell frånvaro av oxidfilm som kan relateras till termisk stress, ureanedbrytningsreaktioner med oxidförbrukande egenskaper eller mekaniskt avlägsnande, t.ex. erosion / Emission control, regulated by evermore strict legislation, put high demands on the development of meticulous exhaust gas aftertreatment systems. In diesel engine emissions, NOx reduction poses one of the major challenges. For heavy duty vehicles, this challenge is often tackled by the use of an SCR system, capable of converting up to 95 % of NOx emissions into nitrogen and oxygen, by use of a selective reductant over a catalyst surface. Ammonia is such a reductant but is not in itself an appropriate choice for mobile applications due to the environmental, health and safety concerns associated with this compound. Hence, an aqueous solution of urea, trademarked AdBlue, is used as a harmless reservoir that upon injection into hot exhaust gas decompose into sufficient amounts of ammonia needed at the SCR catalyst to reduce NOx produced, relative to the load point of the engine. AdBlue injection into the exhaust gas stream can, however, complicate an already complicated system from a material choice perspective. Although, urea is not deemed a particularly corrosive compound, concerns have been raised towards its derivatives often mentioned in relation to a melted urea wall film phenomenon, on exhaust surfaces, generating, solid by-product deposits at the peripheral areas of the film. This work aims to identify some of the risks coupled with AdBlue injection on stainless steel surfaces. Hence, degradation behaviour of austenitic stainless steel grades 1.4828 and 1.4835, is studied after wetting with AdBlue spray in static exhaust gas conditions, 350 ℃ and 700 kg/h. The test bench procedure, provide a cost-effective way of screening potential stainless steels in a realistic exhaust gas environment before component testing. The test of 1.4828 includes a comparison of the grade with and without plastic deformation. Additionally, a martensitic steel component, used in an exhaust gas environment under AdBlue injection, was added to this work to further portray the risks that a material under these conditions must endure. Stainless steels are examined post exposure using confocal microscopy and SEM/EDS. Deposits found on 1.4835 were studied with FTIR. The results portray the risks of a poor material choice and possible absence of oxide film that could be related to thermal stress, decomposition reactions involving oxide consuming properties, or mechanical removal e.g. erosion.
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Adsorption und Desorption von Ammoniak an Fe/BEA-SCR-Katalysatoren in Gegenwart von WasserHahn, Christoph 19 August 2021 (has links)
In dieser Arbeit wurden ein Fe/HBEA-SCR-Katalysator physikalisch-chemisch charakterisiert und die Kinetik der Adsorption und Desorption von NH3 und H2O untersucht. Der Katalysator wurde mittels N2-Physisorption, 57Fe-Moessbauer- und DRUV-vis-Spektroskopie analysiert. Zusätzlich wurde eine systematische Charakterisierung der sauren/basischen Zentren unter Verwendung des HBEA-Mutterzeoliths mit drei verschiedenen Si/Al-Verhältnissen durchgeführt, die 27Al-MAS-NMR-, 1H-MAS-NMR-Spektroskopie und FTIR-Spektroskopie mit Pyridin als Sondenmolekül beinhalteten. Die mechanistische Untersuchung der NH3- und H2O-Sorption wurde mittels in-situ-DRIFT-Spektroskopie durchgeführt, während die Kinetik mittels temperaturprogrammierter Desorption einschließlich verschiedener Adsorptionstemperaturen untersucht wurde. Es zeigte sich, dass NH3 und H2O hauptsächlich an schwach sauren terminalen SiOH-Gruppen adsorbieren, was zu schwachen Adsorbaten führt, während der Protonentransfer an verbrückten OH-Gruppen die gebildeten Adsorbate thermisch stabilisiert. Das an Lewis-Zentren koordinierte Ammoniak zeigte die höchste thermische Stabilität auf den HBEA-Zeolithen, wohingegen H2O an diesen Zentren dissoziiert. Auf der Grundlage dieser mechanistischen Erkenntnisse wurde ein kinetisches Mean-Field-Modell entwickelt, das zwei verschiedene Arten von Adsorbaten impliziert. Diese spiegeln die Tief- und Hochtemperatur-Desorption von NH3 und H2O wider. Die kinetischen Parameter wurden der Literatur entnommen und mit numerischen Anpassungsrechnungen ermittelt, während prä-exponentielle Faktoren der H2O-Adsorption aus der kinetischen Gastheorie abgeleitet wurden. Zur Validierung der NH3-Sorptionskinetik wurden die NH3-Adsorption, das anschließende Spülen mit N2 und die abschließenden TPD-Phase unter Berücksichtigung der unterschiedlichen Adsorptionstemperaturen simuliert, wobei die H2O-Sorptionskinetik die gemessenen TPD-Profile bei verschiedenen Temperaturen zufriedenstellend reproduzieren kann. Die beiden kinetischen Modelle wurden über die Geschwindigkeitsansätze der Adsorption an den schwach-sauren OH-Gruppen gekoppelt, um die H2O-Verdrängungsadsorption von NH3 zu simulieren. Das erhaltene Modell kann die beobachtbaren experimentellen Trends wiedergeben. Zusätzlich wurde die thermodynamische Konsistenz der kinetischen Modelle zur NH3- und H2O-Sorption mittels DSC-Messungen, dem Van't-Hoff-Ansatz und Literaturdaten bezüglich gemessener Adsorptionswärmen nachgewiesen.:1. Einleitung und Motivation 1
2. Zielstellung 5
3. Grundlagen 7
3.1 Heterogene Katalyse 7
3.1.1 Sorptionsvorgänge an Feststoffoberflächen 8
3.1.2 Oberflächenreaktionen 10
3.2 Modellierung von Oberflächenreaktionen 12
3.2.1 Kinetik heterogen katalysierter Reaktionen 12
3.2.2 Stoffbilanzen 14
3.2.3 Numerische Lösungsverfahren 17
3.3 Entstehung von Stickstoffoxiden im Motor 21
3.4 NOx-Reduktionstechnologien in Dieselfahrzeugen 23
3.5 NH3-SCR-Verfahren in Dieselfahrzeugen 25
3.6 SCR-Katalysatoren und Mechanismen 27
3.7 Aufbau und Eigenschaften von Zeolithen 29
3.8 Sondenmoleküle zur Charakterisierung der Oberflächenazidität von oxidischen Feststoffen 33
3.8.1 Ammoniak 33
3.8.2 Pyridin 34
3.8.3 Wasser 35
4. Experimenteller Aufbau 36
4.1 Verwendete Zeolithe und Imprägnierung 36
4.2 Physikalisch-chemische Charakterisierung der Zeolith-Katalysatoren 37
4.2.1 N2-Physisorption 37
4.2.2 DRUV/Vis-Spektroskopie 38
4.2.3 57Fe-Mößbauer-Spektroskopie 39
4.2.4 NMR-Spektroskopie 40
4.2.5 Rasterelektronenmikroskopie 41
4.2.6 Röntgendiffraktometrie 42
4.3 Infrarotspektroskopie zur Analyse der Gaszusammensetzung und Oberflächengruppen 43
4.3.1 Nichtdispersive Infrarotspektroskopie 43
4.3.2 Fourier-Transformations-Infrarotspektroskopie 44
4.4 Untersuchungen zur SCR-Aktivität des Fe/HBEA-Katalysators 45
4.5 Temperaturprogrammierte Desorption 46
4.6 Charakterisierung der Oberflächenaziditäten 48
4.6.1 In situ DRIFT-Spektroskopie ohne Vorbehandlung 48
4.6.2 In situ DRIFT-Spektroskopie mit NH3 und H2O-Vorbehandlung 48
4.6.3 Transmissions-IR-Spektroskopie mit Pyridin-Vorbehandlung 49
4.7 Dynamische Differenzkalorimetrie 50
5. Experimentelle Ergebnisse 51
5.1 Physikalisch-chemische Eigenschaften der untersuchten Zeolithmaterialen 51
5.2 Ergebnisse der SCR-Messung am Katalysator Fe/HBEA 57
5.3 Ergebnisse der TPD-Untersuchungen an den Zeolithmaterialen 58
5.3.1 NH3-TPD-Versuche 58
5.3.2 H2O-TPD-Versuche 65
5.3.3 TPD-Versuche nach Co-Adsorption von NH3 und H2O 70
5.4 DRIFT-spektroskopische Untersuchungen 73
5.4.1 Ergebnisse der in-situ-DRIFTS-Experimente 73
5.4.2 NH3-DRIFTS-Experimente 74
5.4.3 H2O-DRIFTS-Versuche 90
5.4.4 DRIFTS-Versuche mit Ko-Adsorption von Wasser und Ammoniak 95
5.4.5 Ergebnisse der IR-Versuche mit Pyridin als Sondenmolekül 101
5.5 Messung der NH3-Adsorptionsenthalpie am Fe/HBEA-Katalysator und HBEA-12,5-Zeolith 104
6. Diskussion der experimentellen Ergebnisse 106
6.1 Physikalisch-chemische Eigenschaften der Zeolithe und SCR-Aktivität des Katalysators Fe/HBEA 106
6.2 Oberflächenazidität der HBEA-Zeolithe 110
6.2.1 Aluminiumkoordination der untersuchten Zeolithe 110
6.2.2 Art und Wirkung der vorhandenen Oberflächen-OH-Gruppen 112
6.3 Ammoniakadsorption und -desorption an den Zeolithoberflächen 119
6.4 Einfluss der Eisenbeladung auf die Adsorption und Desorption von NH3 bei HBEA-12,5 129
6.5 Wasseradsorption und -desorption an Fe/HBEA 133
6.6 Einfluss von Wasser auf die Adsorption von Ammoniak 143
7. Modellierung 148
7.1 Kinetik der Ammoniakadsorption und -desorption 148
7.2 Kinetik der Wasseradsorption und -desorption 156
7.3 Modellierung der Konkurrenzadsorption von H2O und NH3 162
8. Diskussion der Ergebnisse der Modellierung 166
8.1 Kinetisches Modell zur Beschreibung der NH3-Sorption 166
8.2 Kinetisches Modell zur Beschreibung der H2O-Sorption 175
8.3 Modell zur Ko-Adsorption von H2O und NH3 178
8.4 Thermodynamische Konsistenz der Sorptionsmodelle 183
9. Zusammenfassung und Ausblick 192
Anhang 198
A. Charakterisierung des Verweilzeitverhaltens der TPD-Anlage 198
B. Fehlerbetrachtung zur Gasanalytik 202
Abbildungen 204
Symbolverzeichnis 224
Abbildungsverzeichnis 226
Tabellenverzeichnis 233
Literaturverzeichnis 235
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Är det möjligt att använda SCR-rening av rökgaserna vid inblandning av avfall i biobränslet? / Is it possible to use SCR-technology on the exhaust if waste is mixed in the biofuel?Lind, Ola January 2004 (has links)
<p>Waste appears to be a low-cost fuel compared to biofuel. This Masters thesis was conducted for Vattenfall Utveckling AB and deals with how waste in the fuel affects the performance of a SCR-catalyst. Different mechanisms of deactivation were surveyed, focusing on the poisoning mechanism. A literature study was carried out, which was used as a reference when analysing the results.</p><p>Small samples (9x2x2 cm, 64 pieces) cut out from a full-scale unused honeycomb catalyst were exposed up to 1500h in two different combustion plants, Johannes in Gävle (co-combustion) and Högdalen in Stockholm (waste-combustion). The activity was measured mainly at 300°C but also at 250, 350, 375 and 400°C. SEM/EDS-analysis (about 20 samples) and wet chemical analysis (about 20 samples + 2 fly-ash samples) was then performed on the samples. A sample from each boiler was sent for BETanalysis.</p><p>The results from the analysis above were compared to earlier studies conducted on bio-fuel plants in order to investigate what might have deactivated the catalyst samples. Also a small multivariate data analysis (MVDA) was performed. The results from the study show that the catalyst samples exposed in Johannes have slightly less than 60 % of the activity left after 1500h, for Högdalen only 20 % of the activity remains after 1500h. For Johannes when only firing biofuel the corresponding figure is 74 % and in a coal-fired boiler just over 80 % of the activity remains after 1500h. For catalysts with a higher initial activity the deactivation rate is slower. The main mechanism of deactivation is poisoning from alkali metals. In Johannes the poisoning is mainly due to water-soluble potassium. In Högdalen water-soluble potassium, sodium and acid soluble lead causes the deactivation. Potassium stands for just over half of the poisoning effect, sodium just over 1/3 and lead for less than 1/6. SEM/EDS-analysis shows that the potassium content is about 3 times higher the first centimetre from the inlet, than the rest of the sample. The difference in potassiumconcentration between the surface and the walls of the catalyst is rather small. The concentration of lead on the other hand was found to be constant along the catalyst, but the concentration on the surface is much higher than in the walls. Erosion, sintering and plugging have not been studied in detail. Erosion tends to be a bigger problem in Johannes than in Högdalen, probably due to the texture of the fly ash. It does not seem to be any risk of sintering where the test-bench was exposed. For Johannes plugging was estimated to affect around 25 % of the channels in the samples after 1000h of exposure. Solely exposure for fly ash wasn’t found to affect the activity significantly.</p> / <p>Avfall framstår som ett billigt bränsle jämfört med biobränsle. Detta examensarbete utfördes åt Vattenfall Utveckling AB och studerar hur prestanda för katalysatorn i en SCR-anläggning (för NOx-rening) påverkas vid inblandning av avfall i bränslet. Olika deaktiveringsmekanismer kartlades, med en tyngdpunkt på mekanismen förgiftning. Även en litteraturstudie genomfördes, för att användas som referens vid resultatanalysen.</p><p>Små provbitar (9x2x2 cm, 64 stycken) utsågade ur en fullskalig oanvänd honeycombkatalysator exponerades upp till 1500h i två anläggningar, Johannes i Gävle (sameldning) samt Högdalen i Stockholm (avfallseldning). Aktiviteten mättes, därefter gjordes SEM/EDS-analyser (cirka 20 prov) och våtkemiska analyser (cirka 20 prov + 2 stycken flygaska). Ett prov från varje panna skickades på BET-analys. Analyserna ovan jämfördes med tidigare studier utförda på biobränsleeldade anläggningar för att ta reda på vad som kan ha deaktiverat katalysatorerna. Även en mindre multivariat dataanalys (MVDA) utfördes.</p><p>Resultat från studien är bland annat att katalysatorproven exponerade i Johannes har knappt 60 % av aktiviteten kvar efter 1500h, för Högdalen är motsvarande siffra runt 20 %. Det kan jämföras med 74 % för Johannes om bara biobränsle eldas och drygt 80 % för katalysatorer i en koleldad panna efter samma exponeringstid. Katalysatorer med en högre begynnelseaktivitet deaktiverades långsammare. Den huvudsakliga deaktiveringsmekanismen är alkaliförgiftning. I Johannes beror förgiftningen främst av vattenlösligt kalium. I Högdalen sker förgiftningen sannolikt av både vattenlösligt kalium och natrium, samt syralösligt bly. Av förgiftningen i Högdalen står kalium för lite drygt hälften, natrium för drygt 1/3 och blyet för resten. SEM/EDS-analyserna visade att kalium finns i cirka 3 gånger så hög koncentration den första centimetern från inloppet på proverna för att sedan bli ganska konstant. Det är ingen större skillnad i kaliumkoncentration på ytorna eller i väggarna. För bly är koncentrationen mer jämn i längdled, men i väggarna avsevärt lägre halter än på ytorna. Erosion, sintring och igensättning har inte studerats utförligt. Vad som kan sägas är att erosionen verkar vara ett större problem i Johannes än i Högdalen, troligen på grund av annan textur på flygaskan. Det verkar inte föreligga någon risk för sintring vid platsen för exponeringen. Igensättningen uppskattades i Johannes till 25 % av kanalerna i proverna efter 1000h exponering. Exponering för enbart flygaska i 500h påverkade inte aktiviteten signifikant.</p>
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Estimation, model selection and evaluation of regression functions in a Least-squares Monte-Carlo frameworkDanielsson, Johan, Gistvik, Gustav January 2014 (has links)
This master thesis will investigate one solution to the problem issues with nested stochastic simulation arising when the future value of a portfolio need to be calculated. The solution investigated is the Least-squares Monte-Carlo method, where regression is used to obtain a proxy function for the given portfolio value. We will further investigate how to generate an optimal regression function that minimizes the number of terms in the regression function and reduces the risk of overtting the regression.
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Estudo de viabilidade técnica aplicado ao desenvolvimento do conceito de plataforma ULFPSO com utilização de riser rígido em catenária livre. / Technical feasibility study applied to the ULFPSO platform concept with steel catenary riser.Vilameá, Eduardo Marçal 14 June 2017 (has links)
A exploração de bacias petrolíferas do pré-sal, principalmente campos gigantes como o campo de Libra, na bacia de Santos, traz consigo demandas por sistemas capazes de operar com poços de alta capacidade de produção e em grandes profundidades. Nesse cenário, linhas de produção ou injeção (risers) rígidas em catenária livre apresentam a forma mais simples de solução para essas demandas. A utilização de risers rígidos em catenária livre, como já sabido, permite uma maior produtividade por linha devido a possibilidade de utilização de dutos de maiores diâmetros, ao mesmo tempo em que resistem a maiores pressões, possibilitando a exploração de forma mais eficiente de poços em grandes profundidades. No entanto, este tipo de solução, devido a sua natureza de maior rigidez quando comparado com dutos flexíveis, é submetida a esforços dinâmicos elevados impostos no topo do riser pela grande movimentação da embarcação, principalmente em operações em águas profundas, inviabilizando sua aplicação em unidades do tipo FPSOs convencionais, construídos a partir da conversão de um navio petroleiro. Este problema dinâmico é agravado pelas condições ambientais da região, que são mais severas do que as observadas na Bacia de Campos, tornando difícil a aplicação das tecnologias existentes. A alta produtividade dos poços do pré-sal da Bacia de Santos também estimula a utilização de plantas de processo de alta capacidade de processamento de óleo, maiores do que as utilizadas até hoje no offshore brasileiro. Estimativas iniciais mostram que estas plantas gigantes demandam uma área de convés muito maior do que as plataformas convencionais, e, mais do que isso, de uma maior largura (boca) da embarcação. Para atender requisitos tão conflitantes, foi desenvolvido o conceito ULFPSO (Unidade Flutuante de Produção, Armazenamento e Alívio Ultra-Larga), que se caracteriza por sua proa e popa circulares e pela presença do moonpool, de forma a viabilizar a conexão dos risers mais próximos ao centro de gravidade da plataforma, reduzindo assim o esforço dinâmico. Adicionalmente a forma do casco é otimizada para redução do nível de movimentos verticais, reduzindo os esforços dinâmicos nos risers. Nesta dissertação de mestrado serão apresentados os estudos relativos à comprovação de viabilidade do conceito, dividido em três etapas: A primeira com foco no entendimento do problema e dimensionamento preliminar da unidade; A segunda focada na avaliação experimental do conceito; E finalmente, a terceira, com objetivo de avaliar o modelo de síntese para otimização do projeto do casco, com base nos resultados obtidos nas fases anteriores. / The offshore exploitation of oil fields in the pre-salt, especially giant fields such as Libra, in the Santos basin, brings with it demands for systems capable of operating with high capacity production wells and at ultra-deep waters. In this scenario production or injection steel catenary risers present the simplest solution for these demands. As known in industry, the use of steel catenary risers in free-hanging configuration allows greater productivity per line due to the possibility of using pipes of larger diameters, at the same time withstand higher pressures, allowing for more efficient wells operation at great depths. However, due to its nature more rigid compared to flexible pipe, this kind of solution is subjected to high dynamic forces imposed on the top of the riser by the large movement of the vessel, especially in deepwater operations, impeding their application in FPSO conventional units, constructed from the conversion of an oil tanker. This dynamic problem is compounded by environmental conditions of the region, which are harsher than those observed in the Campos Basin, making it difficult to apply other extant technologies. The high productivity of the pre-salt of Santos Basin wells stimulate the use of plants to high-capacity oil processing process, larger than those used today in the Brazilian offshore. Initial estimates show that these plants require a much larger deck area than conventional platforms and, more than that, a greatest width (breadth) of the vessel. To satisfy such conflicting requirements, the ULFPSO (Ultra Large Floating Production, Storage and Offloading) concept was developed, which is characterized by its circular bow and stern and the presence of the moonpool, to enable the connection of the risers closest to the platform\'s center of gravity, thereby reducing the dynamic tension. Additionally, the hull shape is optimized to reduce vertical movements, reducing dynamic stresses on the riser. In this master\'s thesis will be presented studies on the proof of concept viability, divided into three stages: The first focused on understanding the problem and preliminary sizing of the unit; The second focused on the experimental evaluation of the concept; And finally, the third, to evaluate the synthesis model for optimizing hull design, based on the results obtained in the previous phases.
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Katalytische Umsetzung von Rauchgaskomponenten in imprägnierten kornkeramischen Filterelementen experimentelle und rechnerische Modelluntersuchungen /Hackel, Philipp Marius. January 2007 (has links)
Zugl.: Karlsruhe, Universiẗat, Diss., 2007.
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