Assessment of the use of oxygenated fuels on emissions and performance of a diesel engine

Abstract

Requirements as torque, power, specific fuel consumption and emitted compounds are highly influenced by the chemical composition of the fuel being burned. Thus, the aim of this study was to assess the use of oxygenated fuels on emissions of NOx, CO, HC, CO2 and particle number and size distribution (11.5 b Da b 365.2 nm). In this paper a cycle diesel engine coupled to a dynamometer bench was used, where three types of fuels were employed, B5 (diesel with 5% of biodiesel); B5E6 (ternary composition containing 89% diesel, 5% of biodiesel and 6% of ethanol); and B100 (100% of biodiesel). The performance of a diesel engine was also evaluated to see the impact of the oxygenated fuels in this kind of engine. The use of ethanol with high latent heat of vaporization and low cetane number added to the binary blend (B5) shown an increase in the HC emissions and a reduction in NOx emissions when compared to B5. The use of pure biodiesel (B100) with high oxygen content showed a reduction in the HC emissions, but presented the highest emissions for both NOx and particle number of smaller diameter among the studied fuels. The use of more oxygenated fuels reduced the power output and increased the fuel consumption, but the exergy analysis showed that the energy efficiency of these fuels could be considered similar to the B5 fuel.