Impact of pine oil biofuel fumigation on gaseous emissions from a diesel engine

Abstract

This study aims to investigate the emission reduction potential of pine oil, a plant based bio-fuel, when fumigated in a single cylinder diesel engine. Despite the feasibility of using pine oil as a potential candidate for diesel engine application, big revelation has not been made on its utility in a diesel engine. Therefore, we embarked on a research work to capitalize the renewable source of energy from bio-derived fuel, pine oil, which is much greener to the environment. Pine oil, an oxygenated fuel, possesses lower viscosity, boiling point and flash point, similar to other plant based fuels like ethanol and eucalyptus oil. However, due to its lower cetane number, the operation of it in a diesel engine demands ignition support and the lower viscosity of it necessitates modification with the fuel injection system to avert long term durability issues. Therefore, contrary to the regular method of using biofuels in blends with diesel, this study has attempted to fumigate pine oil in the inlet manifold while diesel was injected through the main injection system. By this measure, homogenized pine oil/air mixture was inducted into the cylinder and ignited by the auto-ignition of diesel. From the experimental investigation, it has been observed that pine oil can replace diesel up to 60% and 36%, at low and full load conditions, respectively. Significantly, smoke emission has been drastically reduced by 64.2% than normal diesel operation at full load condition, with a slight increase in NOX (oxides of nitrogen) emission. Moreover, CO (carbon monoxide) and HC (hydrocarbon) emissions have been found to be 67.5% and 47.8% lower than that of diesel at full load condition. On the other hand, CO and HC emissions were noted to be increased at low load condition; however, the RAE (relative average emission) of HC, CO and smoke was found to be reduced.