Possibility of using biodiesel from sunflower oil as an additive for the improvement of lubrication properties of low-sulfur diesel fuel

Harsh requirements regarding the exhaust gases emission have conditioned the development of new systems in the engine, as well as the development of ecological fuels. Sulfur extraction considerably impairs the lubrication properties of diesel fuel. This has consequences in the rapid wear of the elements that constitute the fuel injection system. Additives for the improvement of lubrication properties are added with the aim of eliminating the adverse effect of fuel. The problem related to the use of those additives lies in the fact that they contain heavy aromatic solvents such as methyl naphthalene, methyl naphthalene and biphenyl which are harmful to health. Therefore, the aim of this research is to determine whether there is a possibility to use biodiesel for the improvement of lubrication properties of fossil diesel with low sulfur content instead of standard additives. In this research biodiesel obtained from sunflower oil was blended with fossil diesel which did not have additionally added additives for the improvement of lubrication properties. The obtained results were compared with the other researches on the use of fossil diesel with added standard additives. The blends of fossil diesel and biodiesel content of 1-7% v v(-1) were used here. The experimental research used different test fuels for the testing of chemical and lubrication properties of fuel, tractor engine performance and exhaust gas emissions. By adding biodiesel, fossil diesel properties remained within the limits set by the standard EN 590 while lubrication properties were significantly improved. On the other hand, power of tractor engine did not change significantly. Although biodiesel had lower heating value with respect to fossil diesel, blending 5, 6 and 7% v v(-1) of biodiesel caused slight increase in the engine power. Tests of exhaust gas emissions indicated that the addition of biodiesel reduced the content of CO2 and CO. The problems related to the use of biodiesel as an additive can be reduced by oxidation fuel stability, increased specific fuel consumption; reduced thermal efficiency and increased NOx emission. (C) 2013 Elsevier Ltd. All rights reserved.