HFRR Studies on Methyl Esters of Nonedible Vegetable Oils

Abstract

The article describes the systematic studies on the lubrication properties of biodiesel, low sulfur diesel fuel, and their blends. Biodiesel from nonedible oils ( e. g., Jatropha curcas, Pongamia glabra, Madhuca indica, and Salvadora oleoides) were prepared by base-catalyzed transesterification using methanol; high-speed diesel (HSD) used was from Panipat refinery. The lubricity evaluation of biodiesel and its blends (5-50%) was carried out as per the ISO-12156 method using high-frequency reciprocating rig (HFRR) test rig. The results indicate that addition of biodiesel to HSD improves the lubricity and provides a stable film on the metal surface. Addition of biodiesel substantially reduces wear scar diameter (WSD). The results were also comparable with pure ester-type compounds synthesized in our laboratory. We concluded that the preferred range of blending biodiesel is 5-20%. WSD of neat HSD is around 0.37 mm, whereas that of all four biodiesels is below 0.20 mm, which is around 50% or less than HSD used. The reduction in WSD at 5% blend is not appreciable except in the case of Salvadora biodiesel, which contains a high percentage of sulfur. At 20% level, around 45% reduction in WSD can be achieved.