Exhaust Emissions of a Medium Power Diesel Engine Operated with Biodiesel

Abstract

The purpose of this study was to identify from experimental researches the results regarding the nitrogen oxides (NOx) emissions and hydrocarbon emissions (HC), emissions of a four-stroke, four cylinder, direct injection of a Romanian medium power diesel tractor engine at partial loads operating on diesel fuel (DF), rapeseed methyl ester (RME), degummed and filtered (5 μm) pure rapeseed oil (RO100) and its blends with diesel fuel: 20% pure rapeseed oil-80% diesel fuel (RO20), 50% pure rapeseed oil-50% diesel fuel (RO50), 75% pure rapeseed oil-25% diesel fuel (RO75) compared to diesel fuel. The main properties of the tested fuels (density, kinematic viscosity, oxidation stability, acid value, peroxide number, coke content, water content and cetane number) have been determined. The value of NOx emissions for the experimented biofuels is smaller up to 53% (for RO100) and increases up to 37% (for RO75) for different engine loads as compared to the diesel fuel. The HC emission shows a decrease for all biofuels used in the experiment ranging between 4% (for RO100) and 63% (RO75) at different loads relative to the diesel fuel.