REDUCTION OF NOx EMISSIONS BY CHANGING THE INJECTION TIMING IN A DIESEL ENGINE FUELLED BY BIODIESEL

Measurements of power and emissions were made in an indirect injection diesel engine with various mixtures of biodiesel from cottonseed oil and diesel (B0, 1320, 1350, 1380, B 100) under various loads at a chassis dynamometer. Data were taken with changing the injection timing -5 degrees before and +5 degrees from its factory setting that was -10 degrees. Measurements were also taken at three different speeds (30 km/h at second gear, 50 km/h at third gear and 80 km/h at fourth gear). Values of exhaust gases (CO2, NOx, CO, HC, O-2 and smoke) were measured with the biodiesel blends and compared with the values of pure diesel as a fuel. The NOx emissions at -5 degrees were reduced by 5.7% from the factory setting for B100. There was also an increase of NO. and a decrease of smoke with increasing the biodiesel content.