Impact of dual biofuel approach on engine oil dilution in CI engines

Biodiesel can be considered to be the most capable alternate fuel for partial or complete replacement of the fossil fuel. Previous studies on biodiesel-oil blends have demonstrated that the use of double biofuels in engine can be a promising aspect for the complete elimination of diesel from compression-ignition (CI) engines. But its use increases the lubricating oil dilution to some extent due to the chemistry of biodiesel. The present experimental investigation describes the effect of biodiesel-oil blend, oxidized biodiesel-oil blend and diesel dilution in the engine oil by means of high frequency reciprocating rig (HFRR) and pin on disc (POD) friction monitor. Moreover, fresh lubricating oil, lubricating oil which was turned out from AB70EU30 operated engine with modified parameters after 100 h and lubricating oil which was turned out from diesel operated engine after 100 h were also considered for experimentation for clear comparison in results. The effects of engine oil dilution were studied on cylinder liner and piston ring as well as on cam and tappet on valve train. The present study revealed that the 10% dilution of biodiesel-oil blend in lubricating oil shows promising result in terms of coefficient of friction and diameter of wear scar as compared to other tested feedstocks. The effect of oxidation of the biodiesel-oil blend on the performance of engine oil is also assessed in the present study. Analytical ferrography of the used oil was also done to study the wear debris in oil.