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  • 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.
431

Influência do biodiesel nas emissões poluentes de um motor turbo diesel

Moreira, Sérgio Manuel dos Santos Reis January 2008 (has links)
Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2008
432

Estudo da influência do biodiesel no funcionamento de um motor diesel

Pimenta, Daniel José Teixeira January 2008 (has links)
Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2008
433

Produção de biodiesel a partir de sementes oleaginosas de mamona.

Araújo, José João Miranda January 2010 (has links)
Tese de mestrado integrado. Engenharia do Ambiente. Faculdade de Engenharia. Universidade do Porto. 2010
434

Estudo sobre a utilização de óleos de origem vegetal em motores diesel não modificados

Espasandin, Rafael Lozano January 2011 (has links)
Estágio realizado na empresa Technická univerzita V Liberec e orientado pelo prof. Doutor Michael Vojtisek-Lom / Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2010
435

Melhoria do processo de produção de biodiesel: : avaliação de vias de valorização do glicerol

Leite, Pedro Filipe Silva January 2011 (has links)
Tese de Mestrado Integrado. Engenharia do Ambiente. Faculdade de Engenharia. Universidade do Porto. 2011
436

Production of Biodiesel from Oleaginous Organisms Using Underutilized Wastewaters

Godfrey, Valerie 01 May 2012 (has links)
Driven by the rising costs, decreasing convenience, and increased demand of fossil fuels, the need for alternative, sustainable energy sources has caused a spark in interest in biomass-based fuels. Oleaginous organisms such as yeast, algae, and bacteria have been considered as microscopic biofactories for oils that can be converted into biodiesel. The process of growing such organisms using current technology requires an alarming amount of freshwater, which is another resource of growing concern. The research detailed within explains how several sources of underutilized wastewater can serve as growth medium in the biodiesel production process. Using only nitrogen and in one case phosphorus as external supplements, algae were shown to grow on produced water from oil and gas industry waste, local municipal wastewater, environmental brackish water from the Great Salt Lake, and wastewater from the potato processing industry. In each case, growth and biodiesel production in wastewaters was as good as or better than laboratory media. The bacterial organism Rhodococcus opacus PD630 and the yeast organism Cryptococcus curvatus were also used to grow on the dairy manufacturing wastewater whey permeate, a large source of underutilized fixed carbon, with successful lipid production. C. curvatus was also used to successfully grow and form large amounts of biodiesel from ice cream factory wastewater and from wheat straw hydrolysate. In each case, the need for freshwater and outside nutrients was nearly entirely replaced, with the exception of some nitrogen supplementation, with a wastewater nutrient source, thus adding to the sustainability of biomass-based fuels.
437

Modelo dinámico para la optimización de un sistema eléctrico en base a biodiesel / Dynamic model for optimization of electrical system based on biodiesel

Sánchez Ramírez, Marcelo Ignacio January 2013 (has links)
Memoria para optar al Título Profesional de Ingeniero en Recursos Naturales Renovables / Las necesidades de energía eléctrica en áreas aisladas han requerido diversos mecanismos de solución, entre ellos el uso de generadores eléctricos en base a biodiesel. La gran cantidad de parámetros o elementos interrelacionados dificulta la toma de decisiones o proyecciones a futuro, y por lo tanto, la posibilidad de replicar iniciativas similares con una confiabilidad viable. Por ello, se desarrolló un modelo computacional de simulación dinámica que permite interpretar la realidad en la producción de una planta de biodiesel, además de optimizar la producción de energía eléctrica e incluso la replicabilidad de proyectos similares frente a realidades distintas. Los antecedentes de origen para la generación del modelo fueron obtenidos por el Proyecto FONDEF D10ER2002 ejecutado por la Facultad de Ciencias Agronómicas de la Universidad de Chile en la provincia de Cauquenes, región del Maule. Allí se utilizaron aceites reciclados provenientes de las principales ciudades de la provincia para satisfacer las necesidades energéticas de dos pequeñas comunidades rurales, promoviendo el reciclaje y el cuidado ambiental. Durante enero y abril de 2013 se obtuvieron los antecedentes del aceite recolectado y el biodiesel generado para desarrollar un modelo de simulación dinámica en base al mecanismo desarrollado previamente, que presenta una serie de pasos previos establecidos y validados para la generación de este tipo de modelos.
438

Alternativa drivmedel : Vilket alternativt drivmedel uppfyller bäst Försvarsmaktens behov? / Alternative fuels : Which alternative fuel meets the Swedish Armed forces requirements?

Djuvfeldt, David January 2009 (has links)
<p>This essay is written within my education for Technical Officer in the Swedish armed forces. The essay describes the alternative fuels that the Swedish armed forces can make use of if the supply of fossil fuels is insecure. The alternative fuels that are described and compared are; Synthetic diesel, Organic diesel, Methanol and Ethanol. The essay describes the process of producing the alternatives, the need for modification and the economics for each alternative. The alternatives are compared and assessed for their ability to secure the supply of fuel to the Swedish Armed Forces. The result of the study is that, while synthetic diesel has the best chemical constitution but is not produced in Sweden, the best alternative fuel for the Swedish armed forces at this moment is organic diesel.</p>
439

Alternativa bränslen Vässarö : Vilka möjligheter har Vässarö rederi att byta till ett bränsle som har mindre påverkan på miljön?

Knochenhauer, Albin January 2013 (has links)
Vässarös rederi bedriver idag transporter av gods och dessutom passagerartrafik, till och från Vässarö, med vanlig diesel som bränsle. I detta arbete undersöks vilka alternativa bränslen som skulle kunna användas i Vässarös fartyg. Syftet med detta arbete är att undersöka hur Vässarös rederi kan byta till ett bränsle som har mindre påverkan på miljön. Information har sammanställts om flera bränsletyper och intervjuer har genomförts med motortillverkare, bränsleleverantörer och ett skärgårdsrederi som genomfört tester med syntetisk diesel. Resultatet visar att ett tänkbart alternativt bränsle är syntetisk diesel och det bränslet skulle ej kräva modifieringar av motor eller bränslesystem och ej heller nya förvaringsrutiner. Biodiesel skulle, efter vissa modifieringar på motor och bränslesystem och även förändrade förvaringsrutiner, också vara ett alternativ. Båda bränslealternativen har kraftigt högre priser och leveransmöjligheterna är krångligare än vid dagens bunkringsförfarande.
440

Biocatalyst Selection for a Glycerol-oxidizing Microbial Fuel Cell

Reiche, Alison 24 April 2012 (has links)
Using glycerol from biodiesel production as a fuel in a microbial fuel cell (MFC) will generate electricity and valuable by-products from what is currently considered waste. This research aims to screen E. coli (W3110, TG1, DH5, BL21), P. freudenreichii (subspecies freudenreichii and shermanii), and mixed cultures enriched from compost (AR1, AR2, AR3) as anodic biocatalysts in a glycerol-oxidizing MFC. Anaerobic fermentation experiments were performed to determine the oxidative capacity of each catalyst towards glycerol. Using an optimized medium for each strain, the highest anaerobic glycerol conversion from each group was achieved by E. coli W3110 (4.1 g/L), P. freudenreichii ssp. shermanii (10 g/L), and AR2 (20 g/L). These cultures were then tested in an MFC system. All three catalysts exhibited exoelectrogenicity. The highest power density was achieved using P. freudenreichii ssp. shermanii (14.9 mW m-2), followed by AR2 (11.7 mW m-2), and finally E. coli W3110 (9.8 mW m-2).

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