EFFECT OF INJECTION PRESSURE ON THE EMISSION CHARACTERISTICS OF A DIESEL ENGINE USING DIESEL-RICE BRAN BIODIESEL BLENDS

Biodiesel as alternative fuel has been widely studied dueto its merits such as lower sulfur, lower aromatic hydrocarbon and higheroxygen content. Rice bran oil is extracted from the germ and inner husk of therice and is not a common source of edible oil. The aim of this paper is tostudy the effect of injection pressure on the emission characteristics of asingle cylinder diesel engine using diesel and the blends of diesel and ricebran biodiesel, B10 (90% diesel + 10% rice bran biodiesel), B20 (80% diesel +20% rice bran biodiesel) and B30 (70% diesel + 30% rice bran biodiesel). Theinjection pressure is varied from 180 bar to 240 bar with an interval of 20bar. The exhaust gas emissions such as carbon monoxide (CO), hydrocarbon (HC),oxides of nitrogen (NOx), carbon dioxide (CO2) and smokeopacity are measured at the rated power and speed at different injectionpressures. It is observed that the minimum CO, HC and smoke emissions arerecorded at 220 bar. The NOx, emissions are increased and CO2 emissionsdecreased with the injection pressure. The optimum injection pressure is 220bar and the blend is B20 with respect to emissions.