Assessment of Lubricity of Biodiesel Blends in Reciprocating Wear Mode 2004-01-3068

Rising scarcity of conventional fuels has forced the development of bio-origin alternative fuels for the existing power generating machinery. These new alternative fuels need to be investigated for their long-term effect on the engine hardware. The biodiesel developed from vegetable oil has been used to partially replace the conventional mineral diesel fuel for diesel engine application. Experimental condition monitoring Study indicated lower wear of vital parts for the biodiesel blend fuelled engine pointing towards inherent lubricity properties of the biodiesel fuel. This phenomenon was experimentally verified in the present investigations. Series of experiments were conducted on SRV optimol wear tester by sliding a pin made of piston material against a disc made of cylinder liner and the lubrication was provided by the selected fuel blends. Various blends of biodiesel containing methyl ester of linseed oil (LOME) in different percentages (0, 20, 40 and 60%) in mineral diesel oil were tested as lubricating fluids in these experiments. The reciprocating friction and wear tests for long duration under various loads indicated lower coefficient of friction for biodiesel lubricated system as compared to the mineral diesel lubricated system. Increasing amount of LOME in diesel oil blend resulted in lower coefficient of friction and specific wear rates. Lower friction and wear of both piston ring and liner disc confirmed that the biodiesel fuel has inherent lubricity properties and its use leads to improved hardware health of diesel engine. After wear tester experiments, the residual lubricating fluids were tested for the chemical changes incurred due to thermal and mechanical stresses by infrared spectroscopy. Surface texture studies were also conducted on the worn surface by Scanning electron microscope to study the type of wear and extent of damage of using different lubricating fluids. FTIR and SEM studies were in conformity with the earlier experiments. SEM studies confirmed lesser damage to the surfaces lubricated by fluids containing LOME.