• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Avaliação da qualidade de ignição para utilização de petróleos pesados e asfálticos como combustíveis marítimos / Evaluation of the ignition quality for use of heavy oils and asphalt as marine fuel

Antonio Fernandez Prada Junior 29 August 2007 (has links)
As correntes pesadas do refino de petróleo podem ser utilizadas para a produção de óleos combustíveis para uso industrial ou marítimo, sendo esse último conhecido como óleo bunker. Para tal, é necessária a diluição dessas correntes pesadas com frações de refino mais leves para ajuste da viscosidade. Enquanto o uso industrial do óleo combustível vem sendo significativamente reduzido em função de restrições ambientais, o mercado de óleo bunker apresenta crescimento importante face a expansão do comércio marítimo mundial. No Brasil, há um aumento da produção de petróleos pesados, extrapesados e asfálticos, que exigem complexos esquemas de refino para a sua conversão em frações mais leves. Dessa forma, ocorre uma redução da quantidade de correntes disponíveis para a produção de bunker, além da variação da qualidade das correntes usadas na sua formulação. Esta dissertação avalia a utilização de petróleos pesados e asfálticos na produção de bunker, sem a necessidade do processamento tradicional em refinarias de petróleo. A comparação da qualidade de ignição e de combustão da nova formulação deste produto com o combustível marítimo preparado a partir de correntes residuais é realizada por duas metodologias diferentes. Após a realização de um pré-tratamento, a mistura formulada a partir dos cortes dos petróleos apresenta melhor desempenho que os combustíveis formulados com as correntes residuais. Além disso, este trabalho compara o efeito de diferentes diluentes e a contribuição da corrente pesada utilizada na qualidade de ignição e de combustão do produto / Heavy streams from crude oil refining can be used to prepare fuel oils for industrial or maritime purposes, the latter known as bunker fuel. In order to prepare them, it is necessary to set viscosity to its appropriate value by dilution with lighter fractions from petroleum refining. While industrial usage of fuel oils is decreasing significantly due to environmental restrictions, the bunker fuel market shows an important increasing face to the growing in world maritime trading. Production of heavy, extra heavy and asphaltic crude oils in Brazil is rising and more complex refining process are required to convert them into lighter petroleum products. Because of that, the amount and the quality of available streams to prepare bunker fuel are decreasing. The present dissertation evaluates the feasibility of using heavy and asphaltic crude oils to prepare bunker fuel without traditional processing into petroleum refineries. The comparison of ignition and combustion quality considering the bunker fuel prepared from residual streams are made considering two different methodologies. After pre-treating the crude oils to prepare bunker fuels, that mixture shows a better ignition and combustion performance than those prepared with residual streams. Finally, this study compares the effect of different diluent streams and the heavy fraction contribution to products ignition and combustion quality
2

Avaliação da qualidade de ignição para utilização de petróleos pesados e asfálticos como combustíveis marítimos / Evaluation of the ignition quality for use of heavy oils and asphalt as marine fuel

Antonio Fernandez Prada Junior 29 August 2007 (has links)
As correntes pesadas do refino de petróleo podem ser utilizadas para a produção de óleos combustíveis para uso industrial ou marítimo, sendo esse último conhecido como óleo bunker. Para tal, é necessária a diluição dessas correntes pesadas com frações de refino mais leves para ajuste da viscosidade. Enquanto o uso industrial do óleo combustível vem sendo significativamente reduzido em função de restrições ambientais, o mercado de óleo bunker apresenta crescimento importante face a expansão do comércio marítimo mundial. No Brasil, há um aumento da produção de petróleos pesados, extrapesados e asfálticos, que exigem complexos esquemas de refino para a sua conversão em frações mais leves. Dessa forma, ocorre uma redução da quantidade de correntes disponíveis para a produção de bunker, além da variação da qualidade das correntes usadas na sua formulação. Esta dissertação avalia a utilização de petróleos pesados e asfálticos na produção de bunker, sem a necessidade do processamento tradicional em refinarias de petróleo. A comparação da qualidade de ignição e de combustão da nova formulação deste produto com o combustível marítimo preparado a partir de correntes residuais é realizada por duas metodologias diferentes. Após a realização de um pré-tratamento, a mistura formulada a partir dos cortes dos petróleos apresenta melhor desempenho que os combustíveis formulados com as correntes residuais. Além disso, este trabalho compara o efeito de diferentes diluentes e a contribuição da corrente pesada utilizada na qualidade de ignição e de combustão do produto / Heavy streams from crude oil refining can be used to prepare fuel oils for industrial or maritime purposes, the latter known as bunker fuel. In order to prepare them, it is necessary to set viscosity to its appropriate value by dilution with lighter fractions from petroleum refining. While industrial usage of fuel oils is decreasing significantly due to environmental restrictions, the bunker fuel market shows an important increasing face to the growing in world maritime trading. Production of heavy, extra heavy and asphaltic crude oils in Brazil is rising and more complex refining process are required to convert them into lighter petroleum products. Because of that, the amount and the quality of available streams to prepare bunker fuel are decreasing. The present dissertation evaluates the feasibility of using heavy and asphaltic crude oils to prepare bunker fuel without traditional processing into petroleum refineries. The comparison of ignition and combustion quality considering the bunker fuel prepared from residual streams are made considering two different methodologies. After pre-treating the crude oils to prepare bunker fuels, that mixture shows a better ignition and combustion performance than those prepared with residual streams. Finally, this study compares the effect of different diluent streams and the heavy fraction contribution to products ignition and combustion quality
3

Metanol som marint bränsle : Alkohol som en lösning, inte ett problem

Hillberg, Torbjörn, Holmberg, Emil January 2014 (has links)
Sedan industrialismens start har människan påverkat klimatbalansen genom förbränning av fossila bränslen. Rökgasemissionerna förorsakade av internationell sjöfart kan inte tillskrivas någon särskild nations ansvar på grund av dess globala och komplicerade verksamhet. FN:s sjöfartsorgan IMO har således åtagit sig ansvaret att minska sjöfartens miljöpåverkan. Införandet av nya miljömål har resulterat i strängare globala och nationella regler som tvingar sjöfartsnäringen till omfattande anpassningar under kort tid. Som lösning för att uppfylla kommande krav gällande rökgasemissioner har flertalet alternativa bränslen diskuterats. Drift på metanol medför låga rökgasemissioner och anses därav ha potential till att bli ett hållbart bränsle inom sjöfarten. Studiens syfte har varit att undersöka vad rederier, maskintillverkare och klassningssällskap anser om metanol som ett alternativt bränsle. Inledningsvis genomfördes en litteraturstudiedel som sedan låg till grund under utformandet av intervjufrågorna. Resultatet visar att metanol anses ha stor potential i jämförelse med andra alternativa bränsle. Då metanol kan produceras från överskottsenergi och transport kan ske med befintlig infrastruktur betraktas det både miljövänligt och ekonomiskt försvarbart. Likväl medför det kraftigt varierande metanolpriset att rederier hämmas att satsa på utvecklingen som krävs för att realisera metanoldrift av fartyg. / Since the start of industrialization humans have affected the climate balance by burning fossil fuels. Exhaust gas emissions caused by the international shipping cannot be attributed to any particular nation because of its global and complex business. The International Maritime Organisation has therefore undertaken the responsibility to reduce the environmental impact of shipping. The introduction of new environmental goals has resulted in stricter global and national regulations that force the shipping industry to make significant adjustments in a short period of time. As a solution to meet future requirements for exhaust gas emissions several alternative fuels have been discussed. Operating vessels on methanol results in low exhaust gas emissions and is therefore considered to have the potential to become a sustainable fuel for the shipping industry. The aim of this study was to investigate what shipping companies, machine manufacturers and classification societies considers about methanol as an alternative fuel. Initially, a literature study was implemented which formed the basis of the interview questions. The result shows that methanol is considered to have great potential compared with other alternative fuels. Since methanol can be produced from excess energy and transportation can be done with existing infrastructure methanol is considered both environmentally friendly and economically viable. Nevertheless, the highly fluctuating methanol price can causes shipping companies to hesitate in the financing of developments that is necessary for the realization of methanol operation on board vessels.
4

Energy analysis and cost estimation of a potential On-shore Power Supply system in the Port of Gävle

Gutierrez Saenz, Juan January 2019 (has links)
The Port of Gävle is one of the most important harbours in Sweden as far as size and freight capacity is concerned. Marine traffic is increasing greatly, thus environmental pollution as well as noise and vibrations are of major concern in port cities. Shore to ship power supply systems might be a feasible solution to curtail emissions because the Auxiliary Engines are instead shut down while the ship stays alongside the quay. The literature review shows they are reliable and very appealing in all respects, thereby contributing to sustainable development. Taking into account the kind of vessels that call at the Port of Gävle, a High Voltage Shore Connection is recommendable, in compliance with the International Standards. An own technical survey is developed to gather all the information, as well as personal interviews to collect first-hand data. Technical issues such as the synchronisation procedure and the ground system with regard to safety are briefly discussed. Due to the lack of data, calculations consist of average values: peak and average demand, and fuel consumption during a typical call. Considering updated energy prices for both electricity and fuel, results show that an on‑shore power supply system make energy costs decrease by 71% at berth in comparison with burning marine fuel, which is saved by around 4 tonnes per call. Additionally, up to 5126 tonnes of CO2 are avoided per year, among other pollutants. Shore‑side power has proven to be profitable and appealing to the Port of Gävle; however, vessels need to be retrofitted, which implies relatively high investments. Collaboration agreements and shipping companies’ willingness to undergo changes are key issues that still need to be solved.

Page generated in 0.0801 seconds