Performance and Emission Characteristics of Diesel Engine Fuelled With Diesel-Biodiesel-Ethanol Blends

For the past few decades, a lot of effort has been made to reduce the dependency on petroleum fuels for power generation and transportation all over the world. Among the proposed alternative fuels, biodiesel and ethanol produced from feedstock were generally considered to be renewable. However biodiesel and ethanol cannot entirely replace petroleum-based fuels, so in order to solve this issue biofuel and diesel blend can be used on existing engines to achieve both environmental and energy benefits. Biodiesel and ethanol added to diesel fuel are known to act as an oxygenated additive, apart from its role as biofuel. In this work, commercial diesel, jatropha biodiesel and various blend of diesel-ethanol-biodiesel in varying proportions ranging from 90-80 % of diesel, 0-15 % of biodiesel, 0-15 % of ethanol, were tested in a single cylinder, four stroke, direct injection diesel engine to investigate the performance and emission characteristics of engine under five different engine loads at a constant speed of 1500 rpm. Engines performance was evaluated by determining the brake specific fuel consumption and brake thermal efficiency. For pollution evaluation the emissions of carbon monoxide (CO), nitrogen oxides (NOx) and unburned hydrocarbon (UHC) have been measured. In comparison with the commercial diesel fuel, biodiesel and DEB blends, DEB blends has an increase of specific fuel consumption, especially at lower engine loads, with maximum of 34.38 %. Brake thermal efficiency of fuel blends is slightly higher than diesel. CO emission for fuel blends having 85 % of diesel has shown smaller decrease at higher loads. NOx emission has increased at higher loads for most of the fuel blends when compared to diesel fuel. Unburned hydrocarbon has reduced considerably at medium loads for most of the fuel blends. Among the various fuel blends D80B5E15 has good performance and emission characteristics when compared to diesel and other fuel blends. D80B5E15 blend would be a better replacement for commercial diesel fuel. Other blends which has good performance, has shown poor emission characteristics and vice versa.