The use of biodiesel or oxygenated fuels from renewable sources in diesel engines is of particular interest because of the low environmental impact that can be achieved. The present paper reports results of an experimental investigation performed on a light duty diesel engine fuelled with biodiesel, gasoline and butanol mixed, at different volume fractions, with mineral diesel.
The investigation was performed on a turbocharged DI four cylinder diesel engine for automotive applications equipped with a common rail injection system. Engine tests were carried out at 2500 rpm, 0.8 MPa of brake mean effective pressure selecting a single injection strategy and performing a parametric analysis on the effect of combustion phasing and oxygen concentration at intake on engine performance and exhaust emissions.
The experiments demonstrated that the fuel properties have a strong impact on soot emissions. Blends composed of diesel-gasoline or diesel-butanol determined the maximum reduction in smoke emissions compared to the diesel fuel. No significant difference for NOx emissions was found between the investigated fuels highlighting that oxygen availability within the fuel may not produce an increase in NOX formation under late premixed combustion.