Effect of biodiesel/diesel-based microemulsions on the exhaust emissions of a diesel engine

Abstract

This paper describes the use of blends of diesel/biodiesel to obtain new microemulsion systems and their application as fuels for diesel engines. The blends were prepared using 5 vol.% (B5) and 20 vol.% (B20) biodiesel in diesel. The microemulsions were composed by either B5 or B20 as oil phase, nonylphenol ethoxylate with five oxyethylene units as nonionic surfactant, and distilled water as aqueous phase. Properties such as viscosity, flash point, density, and corrosiveness were evaluated. In comparison with diesel, increases in viscosity, density, and flash point were observed. Although increase in corrosiveness could be expected, this was not detected with the blends, which were fueled in a diesel engine to evaluate gaseous emissions. A reduction in CO, NOx and smoke emissions was observed, together with an increase in the emissions of unburned hydrocarbons. Therefore, the results indicate that the exhaust emissions of these novel microemulsion systems presented lower pollutants than neat diesel