On the influence of low octane gasoline and biodiesel on diesel engine operating characteristics

Biodiesel is a promising alternative fuel, but it has drawbacks. This research aims to diminish the NO_x dilemma for diesel and biodiesel by utilizing straight-run naphtha as an additive. It has a low carbon footprint of production from light distilled crude oil without any requirement for the thermal cracking process. The diesel was blended with naphtha at percentages of 5%, 10%, and 15% that abbreviated by N5, N10, and N15, respectively. The biodiesel/diesel blend was mixed with the same naphtha concentrations forming the blends B30N5, B30N10, and B30N15, respectively. Experiments were applied on a single-cylinder engine at 2,000 rpm and different loads. The findings revealed that N15 declined the brake specific fuel consumption (bsfc) at most loads relative to neat diesel. Contrarily, biodiesel blends reflected a spiking trend of bsfc at tested loads. Notably, the NO_x emissions declined with N15 blend at high loads relative to neat diesel. The blends B30N15 and B30N10 reduced NO_x at high loads compared to the diesel/biodiesel blend. The straight-run naphtha was found to be a promising additive because the balanced composition of the iso-paraffins and n-paraffins. Hence, it dominated the ignition tendency and reduced NO_x emissions due to its cooling effect.