Tese: Use of Biofuels in Compression Ignition Engines - Potential of Diesel-Biodiesel-Ethanol Blends
Aluno(a) : Florian Alain Yannick PradelleOrientador(a): Sergio Braga
Área de Concentração: Termociências
Data: 10/03/2017
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.29914
Resumo: In order to partially replace the demand of diesel from fossil fuels, to reduce high import costs and to comply with environmental standards, sustainable policies have led to partially replace diesel oil by biodiesel. However, other technologies, such as diesel-biodiesel-ethanol mixtures, are being investigated. The major challenge of these mixtures is to improve the miscibility and the stability of alcohol in diesel. In this study, an additive, from renewable compounds, capable of improving the miscibility of anhydrous ethanol in diesel with 15% by volume of biodiesel was formulated. This additive has improved the range of concentration and temperature in which stable mixtures were observed. Some physicochemical properties of the additivated mixtures were measured to evaluate aspects of consumption, combustion quality, behaviour at low temperature, interaction between the fluid and the surface, and safety. The results showed that blends with, at least 1.0%, by volume of additive and 20% by volume of anhydrous ethanol are stable at temperatures above 10°C and respected most Brazilian specifications for diesel. Experimental tests on a compression ignition engine were performed with these mixtures. The results showed that the diesel substitution alters the characteristics of combustion: the increased ethanol content implied an increase of the ignition delay, a decrease of peak pressure and a faster heat release, but later in the expansion phase. Despite these non-optimized conditions for injection and combustion in the presence of ethanol, results showed a better burning of ethanol to produce a kW.h, in comparison to the values found in flex fuel spark ignition engine, in addition to a small increase in the indicated efficiency of the engine.