Inhibition of NO emission by adding antioxidant mixture in Jatropha biodiesel on the performance and emission characteristics of a C.I. engine

In this paper, the effect of adding an antioxidant mixture in Jatropha biodiesel as fuel, in a single cylinder, direct injection compression ignition engine was experimentally investigated and the level of pollutants in the exhaust and performance characteristics of the engine were analyzed. Nine test fuels were prepared with three antioxidants, namely, Succinimide (C4H5NO2), N,N-dimethyl-p-phenylenediamine-dihydrochloride (C8H14Cl2N2), and N-phenyl-p-phenylenediamine (C6H5NHC6H4NH2) added to neat biodiesel at 500 parts per million (ppm), 1000 ppm and 2000 ppm and the observed experimental results were compared with those of neat biodiesel and neat diesel as base fuels. The comparison showed that NO emission was reduced drastically for the test fuels with the antioxidant addition of 2000 ppm. The maximum reduction of 10% of NO emission was observed for the antioxidant mixture in neat biodiesel, with a slight increase in unburned HC, CO and smoke opacity. In addition, the obtained experimental results reveal that the addition of two antioxidants as mixture in neat biodiesel caused improved NO emission reduction for all test fuels.