Effect of reformulated fuel strategy on compression ignition engine compatibility using antioxidant additive and clean Karanja methyl ester

Abstract

The present work aims at investigating the compatibility of antioxidant with biodiesel through the tribological assessment of a compression ignition engine. In this research work, 2,6-di-tert-butylphenol, a novel antioxidant, has been blended with clean Karanja oil methyl ester at the rate of 500 ppm. The compression ignition engine has been operated for 256 h of long-term durability tests in two different phases using clean Karanja biodiesel (KBD100) and 500 ppm antioxidant-blended clean Karanja biodiesel (KBD100@E). The study revealed that the compression ignition engine operated with KBD100@E fuel has exhibited low lubricating oil degradation when compared to clean Karanja biodiesel at same 256 h of operation. The long-term endurance test also showed that the kinematic viscosity, flash point and total base number of lubricating oil collected from KBD100@E-fueled engine were observed to lower than KPD100-fueled engine. Similarly, the wear metal concentrations were higher in lubricating oil of KPD100-fueled engine than that of antioxidant-added KBD fuel and diesel fuels. Furthermore, the surface roughness results also showed that the cylinder liner surface of KPD100-fueled engine was more smoothened compared to KBD100@E-fueled engine. The wear of piston rings was also noted to be more severe for KBD100-fueled engine when compared to diesel and KPD100@E-fueled engines. Finally, it has been concluded that the compression ignition engine life can be improved by the addition of antioxidant with biodiesel fuel.