Engine performance and emission of a diesel engine operating on waste cooking oil biodiesel

In this research waste cooking oil from restaurants was used to produce pure biodiesel through transesterification, and this converted biodiesel was then used to prepare biodiesel/diesel blends. Experiments were performed on a four strokes, six cylinder, direct injection, and naturally aspirated diesel engine operating on 5%, 10%, 20% and 30% blends with Diesel fuel. The purpose of this research is to investigate the effects of waste oil biodiesel inclusion in diesel fuel on the brake specific fuel consumption (bsfc) of a higli speed diesel engine, its brake thermal efficiency, emission concentrations changes and temperature of the exhausts. At a higher speed of 1800 rpm, the bsfc of the fully loaded engine for the B20 blend is nearly the same as that for diesel fuel, whereas B30 suggests that bsfc is higher by 11.65%. The bsfc of blend B5 appeared to be nearly the same as that of blend B10, both of them having lower bsfc by 2.9% relative to Diesel fuel. The brake thermal efficiency depends actually on both the biodiesel inclusion percent in the diesel fuel and the engine performance conditions. The results indicate that higher than 10 vol % of biodiesel in diesel fuel lowers the fuel energy conversion efficiency for the biofuel. Emissions of NOx appear to increase with increasing biodiesel concentration in the blend, and at the highest load point, the biggest CO emission of 0.08 % vol was measured for diesel fuel, and the lowest of 0.05 % vol was obtained for blend B30, indicating more complete combustion with increasing biodiesel concentration in the blend due to its oxygenated nature.