INVESTIGATION OF THE EFFECTS OF THE DIFFERENT BIODIESELS’ BLENDS ON ENGINE PERFORMANCE

Abstract

Internal combustion (IC) compression ignition (CI) engines running on diesel, play a dominant role of today’s economies, particularly in the agriculture and transport sectors. However, because of diesel associated concerns greenhouse gases (GHG) emissions, coupled with depletion of its reserves together and fluctuations in prices, the biodiesel has gained popularity as a promising alternative fuel. Unfortunately, engines running on biodiesel are associated with decreased power output, poor fuel atomization and increased nitrogen oxides emissions. Biodiesels have been blended with diesel to improve on its properties, however, it has been a difficult to obtain the best blending level, since they are sourced from a variety of vegetable oils whose fuel parameters and interactions differ considerably, causing variation in their combustion processes. Thus, the research aimed to investigate the effects of biodiesels’ blends with diesel on engine performance parameters. Five biodiesels from waste vegetable oil, canola, sunflower, oleander, and coconut oil were characterized and blended with diesel at 10, 15, 20, 25 and 30% by volume. The blends were tested in a 3.5 kW CI engine at maximum speeds and loads. Experiments indicated the biodiesel blends lead to reduced lower heating value, increased density and kinematic viscosity compared to diesel. The blends resulted into increased fuel consumption and nitrogen oxides, while, reducing on brake thermal efficiency and carbon monoxide emissions.